Setting the Contrast Brightness and Color Intensity Curves

The Curves function is the most sophisticated tool for adjusting the color, contrast, and brightness of an image. It does, however, require some effort to learn how to use it. It is easier to work with some of the other tools, such as Levels (tonality correction), Brightness-Contrast, and Color Balance or Hue-Saturation. You can access the Curves tool by choosing Colors > Curves or Tools > Color Tools > Curves. I'll use the example images in this section to briefly explain how this tool...

The Sharpen Filter

Before I start with the following examples, I'd like to point out that that these filters can also greatly improve photographs that are not out of focus. You can gain more visible detail with most pictures through additional sharpening. I use one way or another for sharpening almost all of my photographs. The results make the effort worthwhile. Try it out We applied the Sharpen filter (Filters > Enhance > Sharpen) in section 2.5.12. This filter has the effect of greatly increasing the...

So Far So Good How to Proceed from Here Tips and References

Congratulations You made it through the tutorial. You've learned all the basic techniques to touch up and edit digital photos and images. You became acquainted with the most important tools necessary for producing collages from image elements. You now should have a fairly good idea of how to create your own image and text elements and insert them into an image. If you are looking for further suggestions and assistance for working with GIMP, you can find tutorials as well as pages with tips and...

A GIMP 28 Preview

GIMP was created by a group of independent, noncommercial programmers and is continuously being developed further. In January 2004, GIMP 2.0 was released, followed by version 2.2 in December of the same year. GIMP 2.4 appeared in October 2007, followed by version 2.6 a year later in October 2008. The developers have begun their work on a new and more stable GIMP 2.8. It is still hard to say when it will be released, but some of the goals of the developers are identifiable. Nevertheless, the...

Preparing the Clone Tool Options

Before you start editing your image, take a look at the Tool Options for the Clone Tool. As mentioned earlier, these settings can be accessed in the bottom dock window of the Toolbox or by double-clicking the icon in the GIMP The Clone Tool options are as follows Mode The Mode drop-down menu determines how the color is applied to the image and what effect it will have. If you choose Normal mode, color will be applied without elements being mixed or stacked from the underlying image background....

Creating New Brush Pointers in GIMP and Importing Adobe Photoshop Brushes

To create new brush pointers for future use, just select the Brushes dialog from the dock or access it from the Windows > Dockable Dialogs > Brushes menu option. The Brushes selection window with ready-made brushes. By clicking the little button at the top right, you can access a menu that will let you select the size and alignment of the symbols and layout for this window. The Brushes selection window with ready-made brushes. By clicking the little button at the top right, you can access a...

Thank

This is the second, extended edition of my book in English. First, I'd like to say thank you to my translator, Mr. Thomas Barkley. I think he did quite a job on de-Germanizing this book, especially breaking up my German tapeworm sentences, thus making it readable to my English-speaking readers. And another big Thank You goes to my copy editor, Mrs. Judy Flynn, for her great work on debugging this book. My thanks for the ongoing constructive collaboration goes to all at Rocky Nook and...

Downloading and Installing GIMP

For Linux users, GIMP 2.7 is only downloadable as source code. Thus, Linux users have to compile the application themselves. RPMs and other installation packages are not available. Developer's versions are sporadically available for Windows (*-setup.exe). Linux and Windows users can find the source code or setup binaries on the website of SourceForge When installing GIMP 2.7, you should bear in mind that if you have an older GIMP version installed and want to continue using it, you have to...

Introduction to Fonts

This section will cover features that you'll need to know when dealing with fonts. Sans-serif fonts, such as Arial, Avant Garde, Verdana, and Helvetica, possess a clean, sober, contemporary style. They are often used for titles, captions, and heading. They are not suitable for lengthy reading material because the harder lines can tire the eyes. Serifs are stylistic flourishes, like cross strokes or curves, added to the end of the strokes in a character. Popular serif fonts include Times New...

Typing Text and Defining the Text Attributes

Pntit prl-l l fRfiR 7 layprO 7JIWfi-1. i 1 3 File Edit Select View Image Layer Colors Tools Filters Video Windows Help .1.-1 to i Testtext is text for testing, how text can be tested. TesttestisteKttor resting, how toit cat) te tested. Tim text lias been texted px-- loostpl Rectangle 524x176 2,93 1) GIMP's Text Editor. The text boundary box surrounding the text is visible in the image window. The text is adapted to the new frame size. GIMP's Text Editor. The text boundary box surrounding the...

Typing in GIMPthe Text Tool

The Text tool in GIMP's Toolbox allows you to create dynamic text in an image. It's called dynamic because the process is based on vector representation in spite of the fact that the text is added to an image as a pixel element. Vector representation allows you to post-edit the text as well as its attributes, such as color and font type or font size. When you type text onto an image, the process creates independent text layers, which means that the text is not baked on a background or another...

Real Help GIMPs Help Function

With this book at hand, you should easily get along with GIMP. But if you would like to go into more depth and learn about all of the possible settings, you might try using the Help function. It must be rather tedious for software programmers to develop help programs and documentation. They seem to be written after the fact. For GIMP, this definitely has been the case. Sometimes you may rely on the Help function and it responds by opening a window that says Eeek The Help function is missing...

Preface to the Extended Second Edition

A good three years have passed since the first publication of my book GIMP 2 for Photographers. In the meantime, the new GIMP 2.6 has become available. Essentially, the subdivision in separate dialog boxes has remained the same. However, there have been various modifications in the segmentation and layout of the menu bars as well as in the appearance, characteristics, and handling of windows. New tools and functions have been added to the menus. Some tools offer new additional functions such as...

About GIMP

GIMP is an acronym for GNU Image Manipulation Program. GIMP was bred from the Linux world and is an open-source software program covered by the General Public License (GPL). GNU means GNU's Not Unix and refers to a collection of software based on the UNIX operating system and maintained by the Free Software Foundation. GIMP is the Photoshop of the Linux world it is the best free image editing program. GIMP 2.6 was introduced in October 2008. This enhanced version of GIMP meets the functionality...

Using GIMP 26 About This Book

If you are reading this book, you are probably interested in learning how to touch up your digital photographs or create your own graphics or logos. However, before investing hundreds of dollars on expensive software, you may want to make sure that manipulating digital photographs is something you truly enjoy. That's where GIMP 2.6 a free digital image editing program comes in. You most likely want to learn how to use this free software to improve your photographs. This book is designed to...

Crop and Rotate

The functions under this tab provide, as the name implies, the tools to crop, rotate, and shrink your images. You can also flip the image horizontally or vertically. I used it right in the beginning to set the picture upright. The image is set at an aspect ratio of 13 18. In the preview window, you can see black beams on the left and right that indicate where the image will be cropped. By clicking the left mouse button on the preview image, you can determine the section to be cropped. The image...

The Perspective Clone Tool

Originally, to introduce a new image element into another image with the correct perspective, GIMP only had the transformation tools, such as the Perspective tool. Since GIMP 2.4, we have the additional choice of the Perspective Clone tool to copy sections from an image with the help of a clone tool. These sections can then be placed into the intended image in the correct perspective. The intended use of this tool is to cover up trouble spots in digital photography with image content in the...

Why You Need Smooth Brushesthe Clone Tool

The Clone Tool uses image data and patterns to draw not only colors, but also color structures. These structures are actually pieces of your image that you previously copied from a defined area in the same image. This tool is capable of doing more than just working with normal opacity. Since you can set the tool's opacity from opaque to transparent, you can use this glazing technique to create smooth transitions, using a soft, feathered pointer. The Clone Tool is considered the touchup tool....

Adjusting the Display with a Calibrating Program

The previously mentioned changes in your default settings lay a good foundation for a good color rendering on your monitor and for editing your images. Should your images still have strong variances in color and brightness in your prints, you can try adjusting with a calibration program. There are programs that are able to achieve a comprehensive and exact calibration of your monitor. They use a device that measures and calibrates your monitor. An affordable calibration program for amateur...

Hints for Working in Grayscale and RGB Modes

By default, GIMP works in RGB color mode, which supports the representation of approximately 16.7 million colors. This color mode supports all the tools available for manipulating colors or color values in an image. In addition, GIMP offers the grayscale mode. Grayscale corresponds to a limited color palette of 256 gray levels, including black and white. All tools used to manipulate brightness and contrast levels are supported in grayscale mode. However, tools, filters, and options that...

Characteristics of Pixel Images

GIMP is used primarily for editing pixel or bitmap images. Pixel images are made up of tiny dots called pixels these images are somewhat like mosaics in structure. All photographic images captured by a digital camera or copied by a scanner are pixel images. The pixel image is considered standard. ' _ ' Ihnjttif-injRm 1 lajigrllTfinflWin- I jj & P File Edit Select View Image Layer Colors Tools Filt ' _ ' Ihnjttif-injRm 1 lajigrllTfinflWin- I jj & P File Edit Select View Image Layer Colors...

Creating Light Reflection with Filters

In addition to graphic and painting techniques, GIMP offers a number of filters that simulate special lighting situations or simply set highlights and also can be used to create lens reflections in an image. The Supernova filter (menu Filters > Light and Shadow > Supernova) can be used to make radiating reflections depending on the radius setting. You were introduced to this filter in section 3.6.5. Light reflections created with self-made brushes and the corresponding settings in the Brush...

The IWarp Filter a Closing Comment

As compensation for all the hard work, I would like introduce you to something more cheerful. Take a look at the IWarp filter (Filters > Distorts > IWarp). The filter allows you deform an image interactively by using the Settings options. This procedure is also known as morphing. It is not only used for fun, it lets you make lips fuller, breasts more shapely and eyes brighter. This is really used for beauty enhancement in magazines and advertising. You could animate an image you've modified...

Scaling the Print Size of Images An Example for Converting Resolution and Size

When you open an image imported from your digital camera, GIMP tells you what the image dimensions are in the Image > Print Size window. For example, it might read as follows 1200 pixels X 1600 pixels 16.667 inches X 22.222 inches with a resolution of 72 pixels inch (the figures of this example refer to the size and resolution of a 2 megapixel image from an elder camera). If you want to reduce the image to print size of 5 X 7 inches, for instance, you must set the value for Height to 7...

Converting Images into Blackand White Graphics

Using the Threshold function to achieve graphic effects in black-and-white Using the Threshold function to achieve graphic effects in black-and-white It is possible to convert images into pure black-and-white graphics with GIMP. Threshold is the quick-and-dirty function used to convert images and can be found in the Colors menu. It doesn't matter if the image is a color or grayscale image, it converts the image into a pure black-and-white graphical image. The only option for adjustment is the...

Cross Fading Part 3Merging Images into one Pseudo HDR

GIMP doesn't offer any features for merging HDR images. However, I would like to show you a method to reach similar results. Actually, it is used to cross-fade parts of images, letting you merge images, but you can also merge bracketed photos with this method. In addition, you can create the basis for a pseudo HDR image by editing one preferably underexposed image with the tonality corrections in three different variations, saving each variant as a new image. In the SampleImages folder on the...

The Layers Dialog

The Layers, Channels, Paths, Undo window (Layers dialog) The Layers, Channels, Paths, Undo window (Layers dialog) You can access the Layers dialog either from within the Windows > Dockable Dialogs menu item or from the Windows > Layers, Channels, Paths, Undo menu item in the image window. By default, when you start GIMP, it displays the Layers dialog in a window together with the dialogs for channels, paths, and the undo history. You can click a tab to select one of these dialogs (upper...

The Graphical Library GEGLDeveloping Blackand White Images with GEGL Operations

Developing black-and-white images using the GEGL Operation mono-mixer Developing black-and-white images using the GEGL Operation mono-mixer The Generic Graphics Library (GEGL) has been integrated in GIMP with version 2.6. It is supposed to be expanded to ensure image editing with more than 8 bits per channel with GIMP. Some of the computation functions based on GEGL are already assembled in the GEGL Operation window , which can be found by choosing Tools > GEGL Operation. In the Operation...

Programs for Creating Panoramas Automatically

Several programs are available through the open-source community that will automatically produce panoramic images. The tools Hugin and PTGui are available for Windows, Linux, and Mac OS operating systems. Autostitch, a tool available only for Windows, is easy to use but for JPEG files only. This one is shareware. PanoTools is a plug-in for GIMP 2.0 (Windows). However, so far it can't be used for the newer GIMP versions under Windows. But it is worthwhile to download it as a stand-alone program....

Performing Magic Editing Photographs with Graphic Filters

You can find all of GIMP's filters in the Filters menu. The script-fus are also found there. Script-fus are output sequences, so-called macros, that work according to a defined yet adjustable procedure. Actually, most filters in GIMP are script-fus, written in the GIMP scripting language Scheme and saved as scm-files. You have already become acquainted with some effects and even filters for editing your photographs, such as the Gaussian Blur filter (Filters > Blur) and the Sharpen filter...

Introduction to Working with Layers

Imagine you want to compose an image from several images that you've stored on your computer. Well, you can do just that The process is similar to the production of animated cartoons. You begin with a background image. Then you place one or more transparent foils (which are layers comprising image elements on top of transparent backgrounds) on the bottom, or opaque, background layer. A stack, a collage of single images, is created, one on top of the other. Certain file formats let you save...

Adding Special Characters

GIMP's Text Editor lets you type all characters you find on your keyboard. Special characters, such as the copyright character, , or accented characters, such as n, are not included. However, Windows users can find special characters and Unicode key positions in the Character Map, which can be accessed from Start > Programs > Accessories > System Tools. Simply, with a right-click of your mouse, you can copy and paste the characters into GIMP's Text Editor. The prerequisite for this and...

Using the Threshold Function to Extract Hairthe Task

The following example focuses on increasing existing contrast levels so you can achieve the most exact selection of fine structures possible. Though this solution is not perfect, it may serve as a brainteaser for developing your own solutions. First you'll want to choose Colors > Threshold so that you can create a mask layer with high contrast. You can employ painting tools to touch up this layer and subsequently use it to create selections that will help you to edit the actual image. fi...

Eliminating the Red Eye Effect

Since GIMP 2.4, there is a filter to eliminate the red-eye effect. You'll find it by choosing Filters > Enhance > Red Eye Removal. The filter is easy to use and efficient. You can follow the steps as we go along. To do this exercise, open the image redeyes.bmp in the SampleImages folder on the DVD and save it in your exercise folder. The Red Eye Removal window. To focus the effect of the filter, I selected the area around the red pupils with the Free Select tool. Otherwise all red objects...

Sharpening Images and Image Elements

No filter or tool can make a major improvement if your photo is strongly blurred. But if your picture is only slightly out of focus or has a shallow depth of field, you can sharpen it easily. However, it is not possible to improve the quality of the picture. Pictures aren't enriched with more detail. Instead, the existing details and contours are accentuated by enhancing the light dark contrasts at the edges of the objects and contours in the pictures (especially with the Unsharp Mask filter)....

Short Introduction to Working with Layer Masks

To proceed from here, you must first consider what you want to take from which layer. Starting with the topmost layer, details-highlights, you will need the sky and the branches of the trees. You can delete or, better, hide the rest of the layer, using a layer mask. Next, you will need the temple and the tree trunks from the second layer. Since the sky remains in the topmost layer, you won't need to worry about the sky on the median layer. It will be covered by the sky of the topmost layer. You...

HDR Software

To create HDR images, you need special software. GIMP can be used to edit only images with 8 bits per channel, but there is a Python plug-in that will create HDR images with the help of GIMP. More information and the download can be found at The open-source community offers Cinepaint (previously known as FilmGIMP or Glasgow) for Linux, Windows, and Mac OS for creating HDR images (as mentioned in section 1.5.1). You can find the download and tutorials at the following locations http...

Importing Brush Pointers from Adobe Photoshop into GIMP

It is comparatively easy to import brush pointers from Adobe Photoshop or Adobe Photoshop Elements into GIMP. You simply have to copy the brush set files from Photoshop with the extension abr. You can find them in the Presets Brushes subdirectory of your Photoshop installation directory. Copy the file into the brushes folder in your GIMP installation. (The entire path in Windows is You can find a variety of prepared brushes for Photoshop and GIMP as free downloads on the Web. Simply enter the...

The ScriptFu Layer Effects

Adobe has special effects in Photoshop, the so-called layer styles or layer effects. This collection includes effects like Drop Shadow, Bevel and Emboss, Outer and Inner Glow, and so on. Jon Stipe developed an equivalent script-fu for GIMP called layerfx.scm. You can download it from http registry.gimp.org node 186. You can also find it on the DVD in the folder GIMPScript-Fus. Installing script-fus and filters is described in section 1.5.2. After the installation in GIMP, you must select Filter...

The Free Select Tool Polygon Lasso as a Select Tool

The polygon lasso has been introduced to GIMP in version 2.6. You can cut out image objects precisely along the contours and quickly extract constructed, preferably straight forms. I'll show you how to use the polygon lasso in the following section. You must work cautiously when you are making a selection, and you must adjust the settings when you are extracting a rounded form such as a wine glass. Actually, GIMP has a tool better suited for these kinds of tasks -the Paths tool. But you will...

The Color Picker Tool Using the Eyedropper to Select a Foreground Color from the Image

You can use the Color Picker tool to select any color on an active layer or image. If you select this tool and click on a color on your image, you can select this color as the foreground or background color. The foreground color is used when you're painting, filling, or adding text. In GIMP, the foreground color is also the default color for color gradients. Using the Color Picker is the most simple and comfortable way to select a paint, fill, or text color. Thus, you'll be learning it first,...

Using Channels to Extract an Object from the Background

As you know from section 1.3.3, the colors you see on your monitor are created from three primary colors red, green, and blue. The same holds true for images in RGB mode All colors in an image are mixed from these three primary colors. Accordingly, each image in RGB mode consists of three channels red, green, and blue. Each channel is a chromatic component representing the share of the corresponding color in the image. You have been introduced to channels in the previous exercises, even though...

Creating a Selection with the Polygon Lasso Following a Contour

The arrow indicates the starting point of the tool. The arrow indicates the starting point of the tool. First, determine the starting point of your selection by clicking onto one point on the contour of the image object you want to select. Now let the mouse-button go and shift the mouse cursor along the object's contour you are pulling on the rubber band of the lasso tool. Apply the rubber band to the contour and set another point on the contour by clicking. By additional clicking and dragging,...

The Foreground Select Tool Extracting Images Automatically

Before we turn to a work-intensive method where we mask image objects by hand, I will show you the automatic method. The Foreground Select tool that has been included in GIMP since version 2.4 offers a method to easily extract objects in images. Let's have a look at what the tool can do. First of all, an easy exercise Extract an orange basketball that is in front of a green background. Open the image basketball.png from the Samplelmages folder on the DVD. Select the Foreground Select tool in...

Using Filters to Color and Bleach an Image

Gimp Sketch Effect Script

Some filters offer the option to subsequently color your image, give it a vintage feel, and make it look like a pencil drawing or convert it into a grayscale photocopy. An interesting filter to color images can be found under Filters > Decor > Old Photo. This filter can create more than just a sepia-toned photo. If desired, the image can be altered with various effects to give it an aged look. However, this script-fu doesn't have a preview function. You just have to activate or deactivate...

Saving Your Image

When you have finished editing an image, you can hand it over to GIMP. You can also save it as a stand-alone version directly out of UFRaw. The Save tab offers you the following options Path - The path to the folder in which you want to save the file. Filename - The name of the file. File type or format - The format in which you want to save it PPM, PNG, TIFF, or JPEG. Compared to earlier versions, you don't have the option of choosing the color depth (8 bits or 16 bits per channel). The images...

Adjusting Hue and Saturation

Have a look at your miami-impro image with the Hue-Saturation function open (Colors > Hue-Saturation). What could you do with it Let's see The sky over the houses is cyan and turquoise. Move the Hue slider slowly to the right and observe how the color of the sky changes. It slowly changes to blue, but the other colors in the image also change with it. The Master button is the default setting for the Select Primary Color to Adjust function, so all primary colors are selected. When you move the...

Native GIMP File Formats

Note GIMP 2.6 can also save animations in MNG format, a format derived from PNG for animations for the Internet. However, most browsers, except for the Konqueror, don't support this format yet, or they support it only when you have installed an additional plug-in. *.pix, *.matte, *.mask, *.alpha, *.als FITS Flexible Image Transport System JPEG Joint Photographic Experts Group *.im1, *.im8, *.im24, *.im32, *.rs, *.ras po GIMP supports the following RAW camera formats without UFRaw, but so far,...

Whats on the DVD

First of all, you will find this book in PDF format Goelker_GIMP2_6ebook. pdf on the DVD. You may want to copy this to your computer so that you can quickly search for specific topics. The DVD also contains a folder named SampleImages where you'll find master copies of all images used in this book. You can use them to practice the exercises found in the tutorial. You will also find the finished images from most exercises in the FinishedImages folder so you can compare your work. In addition,...

Changes in GIMP

The following changes have been made in the developer version 2.7.0 from The Paint tool settings ink not included will include more options The Brush Dynamics option will be complemented with the settings Direction and Cant. An Angle setting will be added to the Pencil, Paintbrush, and Airbrush tools. A zoom will be added to the brush selector in the Toolbox. The selection can be viewed in a list or in a palette. In the Brushes dialog, the individual brushes can then be tagged in order to...

Essential Monitor Settings

Every device scanner, monitor, printer has a slightly different color calibration. You can add a color profile to the image so that the color is consistent on all the devices and color shifts can be kept to a minimum. There are two possibilities to ensure a consistent color reproduction on all output equipment. Initially, it may be enough to select a suitable color profile for your monitor and to adjust it to GIMP or any other editing program . Should the printout still deviate from your screen...

Copying a Wine Glass and Creating a Drop Shadow Overview of the Steps Involved

Follow these steps to copy a wine glass and create a drop shadow Open the wineglass.png image from the SampleImages folder. Select the Paths tool to create a path, following the contours of the wine glass. Create a selection from the path add 3 px of feathering to the selection. Select the Edit gt Copy menu item to copy the wine glass. Choose Edit gt Paste and insert as a new layer in the image. Remember to name the layer. Save the image without combining the layers as wineglass2.xcf. Copy the...

GNU Image Manipulation Program

Copyright 2002,2003,2004,2005,2006,2007,2008,2009 The GIMP Documentation Team Legal Notice Permission is granted to copy, distribute and or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation with no Invariant Sections, no FrontCover Texts, and no Back-Cover Texts. A copy of the license is included in the section enphrased aGNU Free Documentation License. GIMP's Help user manual appears in a...

Touchup Work 2Removing Spots Dust and Scratches

Older images or slides often have blemishes, such as creases, dog-ears, spots, dust, scratches, and missing edges. Also when you scan slides, lint and dust often end up on the image. Even digital images can have disturbing elements that need retouching, such as overhead wiring in the picture or dust on the camera chip. The touchup work involved to fix such images is called constructive touchup since it involves reconstructing image elements. Constructive touchups also include removing image...

Editing Overexposed Images

Don't throw away your image even if it has been overexposed or the flash was too bright. You can improve it by applying the Levels Adjust Color Levels or Curves Adjust Color Curves function. However, it may be much quicker and more efficient if you use layers and the various layer modes. If you would like to follow along with the following example, simply open one of your own overexposed images or the image overexposed.png from the SampleImages folder on the DVD. After opening the image in...

Panoramic Photos

Images composed of several distinct shots are often called panoramic photos. You can shoot such images freehand. Unfortunately, panoramic photos often suffer from horizontal or vertical mismatches, distortions, or canted sides. If you use a tripod when shooting panoramic photos, it will be easier to combine the images. In any event, make certain that about one-third of each image can overlap onto the other images so that the dissolve will appear natural and smooth. It is extremely important to...

The Change Foreground Color Window

The color area is GIMP's basic color palette. It consists of two colors, the foreground color and the background color, and you can use it to choose colors for painting, writing, or filling. Clicking on any color brings up the Color Editor dialogs. The Color Editor dialog Change Foreground Color and the representation of the color selected in the Toolbox The Color Editor dialog Change Foreground Color and the representation of the color selected in the Toolbox In the Change Foreground Color...

Scanning Your Image

As mentioned earlier, a separate program usually the scan program that came with your scanner actually processes a scan, even though you're capturing the image within the image editing program. Because scan programs vary according to the make and model of the scanner, the example dialogs may be slightly different than what you will actually see on your computer screen. To scan an image from within GIMP, select File gt Create in the Toolbox. The File gt Create menu and the Select Source window...

Transforming Pathsthe Shear Tool

Now you'll continue working on your image. In the Paths dialog, click the Duplicate path button and enter a name for the new path, such as wine glass shadow. Activate the wine glass shadow path and click the Path to selection button. You'll know the object has been selected when you can see the marching ants around it. Access the Select gt Feather menu item to define a border feathering of 3 px. Choose Edit gt Copy and make a copy of the wine glass. Check the Layers dialog to make certain that...

Removing Lens Distortion Making Perspective Corrections and Reducing Vignetting

Even after correcting the perspective in the previous exercise, distortions and warping still remain. This is due to the fact that the image was put together as a panorama picture using several individual photos taken with a wide-angle lens. In addition, the image has a left and a right vanishing point. To correct these defects, GIMP offers the Lens Distortion and Curve Bend filters. These filters provide not only perspective corrections, but also to a certain extent corrective measures for...

Changing the Image View Size Zooming

Changing the view size of your image will not affect the actual image or file size. The view options customize how you see the image on your computer screen, allowing for easier editing and detail work. You can zoom in and out on an image by using the Zoom Tool Magnifier , which can be found in the Toolbox. When you click the Zoom Tool, the cursor will change into a magnifier icon. Clicking the magnifier on your image will enlarge the image, and the spot where you clicked will become the...

Removing Dust and Other Small Irregularities

In section 2.5, we gave the scanned newspaper clipping from Miami a new shine. So far, we were quite successful. Nevertheless, the picture still has some blemishes that need repair. For example, there is still a visible cell structure from raster printing at the rear of the car. a miarcii-impro.tif-12.0 RGB, 1 layer 1S05j1121-G MP File Edit Select View Image Layer Colors TqqIs Filter Video Windows Help 0 . I . IMP I P I , I I , I .JTOP ' f lt y lerWt ii nRlnr _J a miarcii-impro.tif-12.0 RGB, 1...

Starting GIMP for the First Time

When you launch GIMP for the first time by double-clicking the GIMP icon on the desktop or by choosing Start gt All Programs gt Gimp , a dialog box pops up. Use it to set up GIMP according to your personal preferences. For standard use, accept the settings and click Continue to proceed. When you are asked to choose a temporary directory for GIMP, you can type C Windows Temp, which is Windows' default directory for temporary files. This is the standard directory for Window temporary files and...

Tips for Handling Select Tools

The select tools are essentially used to select one or more portions of an image for further editing. For example, you might want to create a filled shape to cover an undesirable object in your photo, or you might want to experiment with the functions in the Colors menu to adjust a selected image section without worrying about affecting the entire image. Selected image areas can be copied and pasted in as separate elements. You can also use the select tools to cut and or delete a detailed area...

Color Management in GIMP

Apart from calibrating your monitor, you can install an updated driver to get rid of problems with color rendition and brightness in your prints. Generally speaking, the home printer and photo printer can't be calibrated. This option is only available for professional printers. Nevertheless, with the help of color profiles, most printers can be adjusted to the color rendition of monitors programs. This is where color management is necessary in GIMP. Since GIMP 2.4, it is a standard feature. You...

Creating a Sky Graphically The Difference Clouds Filter

GIMP has a filter that lets you create clouds graphically. To use it, choose Filters gt Render gt Clouds gt Difference Clouds. Create a new layer in bluesky.xcf in the Layers dialog. Name the layer cloudysky. Fill the layer with the color white with the help of the Bucket Fill tool. Then open the Difference Clouds filter. The cloud structure is depicted in gray in the preview window and will be colored later. You can experiment with the slide controls to create the structure and density of the...

Using the Levels Function to Correct Color Cast

Colorcast Png

Open the image colorcast.png in the SampleImages folder on the book's DVD and save it in your exercise folder. You will notice that the image has a distinct red color cast, which means that the red color channel values are faulty. The colorcast.png image has a strong red color cast. You can use the function Levels in the Colors gt Levels menu to correct the bright-dark values in the image. Using the Levels dialog that appears, first change the settings of the RGB color channel by clicking the...

Features and Elements of UFRaws Main Window

The selected file will open in UFRaw's main window. The tabs with the controls and functions are located on the left side of the window. The order in which the sliders and tabs are arranged suggests the order in which you should use them. On the right is the program's preview image. All the changes you make to the image appear in real time. You can rotate your image with the Crop and Rotate tool, located in the seventh tab on the left side of the window. Most tabs have symbols depicting the...

Setting the Image Size and Resolution

Before we talked about changing the view size of the image, it had already been rotated. So the image should be upright now. Next, you'll want to set the size and resolution. Let's say you want your image to be the size of a photo print, 13.5 cm x 18 cm, about 5 in x 7 in, so it can easily fit on one print page. The target resolution of the image is 300 dpi. Options for setting the size and resolution are located in the image window just choose Image gt Scale Image. When the Scale Image window...

Covering Up Blemishes with Noise

Open compressionartifacts.jpg from the Samplelmages folder on the DVD. Enlarge the image by 200 so you can make out the compression artifacts. The HSV Noise filter window. In the image window, you can see the result of applying the filter. The HSV Noise filter window. In the image window, you can see the result of applying the filter. USING GIMP CORRECTING AND TOUCHING UP YOUR IMAGES Select the HSVNoise filter Filters gt Noise gt HSVNoise . The filter scatters pixels through the image. You can...

Setting the Contrast and Color Levels Tonality Correction

Correcting tonality will improve the quality of almost any image. GIMP offers several options to do this. The Levels options tonality correction can be found via Tools gt Color Tools gt Levels or Colors gt Levels. The most striking effect in the Levels dialog is the Input Levels curve, which is referred to as the color histogram of the image. Initially, it is created from the image's RGB color channel Channel Value . The curve shows how the color lightness values are distributed in the image....

The Despeckle Filter

2.8 PERFORMING MAGIC - EDITING PHOTOGRAPHS WITH GRAPHIC FILTERS l I in In the Samplelmages folder on this book's DVD, you can find the image noise. png. The photo is a night shot originally saved as a JPEG. The image has been brightened with the Levels tool. This increased the noise contamination in the picture. First we will apply the Despeckle filter Filters gt Enhance gt Despeckle . The filter gives a soft-focus effect that seems to smudge the flecks in the image. When you first open the...

Using the Gradation Curve to Correct the Tonality

Gradation Curve

The tonality of an image can be corrected by moving the bottom and top end point of the diagonal gradation curve horizontally toward the inside of the histogram while holding the left mouse button down. You can now place additional control points along the curve. In our example image, the colors in the shadow range dark colors were moved slightly upward. This caused them to become more distinct and brighter. The midtones were shifted up a little bit too, so they became lighter. The highlights...

The Image Window Your Workspace

The image window is the main window that appears when you open an image. This is your actual workspace. Although initially the window will show your image in full size, you can decrease its size so you can use the remaining space in the window for your palette and tools. The image window is maximized and now also serves as the background window of the program. The image window is maximized and now also serves as the background window of the program. A second image has been opened in a new, free...

Using the Gaussian Blur Filter to Remove the Moir Effect

Next, you'll want to remove the moir effect from the image. For this action, you will use a filter called Gaussian Blur Filters gt Blur gt Gaussian Blur . As a rule, most filters should be used after you've finished with all other image editing work. Remember to save a copy of the image before using a filter. However, the Gaussian Blur filter is an exception if you are using it to remove the moir effect. After selecting the Gaussian Blur filter, use the dialog to set the amount of blur desired....

Printing Images

To print images from within the GIMP, you'll obviously need to connect a printer to your computer and make sure a recent driver is installed. Generally, you can find drivers via a Download or Support link on the printer manufacturer's website. Gutenprint offers drivers for Linux and Mac OS X at http gimp-print.sourceforge.net . Altogether, Gutenprint has over 700 drivers available that work with CUPS, LPR, LPRng, and other UNIX printing systems. Therefore, you can use the GNU General Public...

Second Method to Remove Color Cast Color Balance

Color Balance not only corrects images with color cast, it can also be used to adjust colors in general, freshen up colors, or even change or intentionally distort colors. To introduce this function we will work with an image with an excessive color cast. However, it is better suited for color corrections in images with very little color deviation. Open the colorcast.png image from the DVD again. Access the Color Balance function by choosing Colors gt Color Balance. The Color Balance window...

Dark Frame Subtraction

Many cameras apply dark frame subtraction for long exposures to reduce noise and remove so-called hot pixels. The disadvantage of this procedure is that it makes the exposure twice as long because the dark frame exposure time needs to be as long as the exposure time of the real image. You can make your own dark frame by putting on the lens cover and taking a picture. However, you have to do this where and when taking the original shot on location, not afterwards. The camera chip's temperature...

Color Reversal and Solarization Effects with Gradation Curves

Applying the appropriate settings on the gradation curve can change the image into its negative or develop a color negative into a positive. If you position the end points of the gradation curve so that the shadows are completely brightened and the highlights are completely darkened see figure 2.52 , a color reversal results. An image can be converted into an negative. A negative, on the other hand, can be developed into an image with correct colors. You can also use gradation curves to adjust...

Shadows Highlights Correcting backlit photographs with the gradation curve

Backlit photographs constitute a difficult situation in photography. The surfaces of the photographed objects in the foreground appear shaded. In a contrary but similar manner, photographs taken with a flash are overexposed in the foreground. As long as there is enough distinguishable image information available, you are able to improve these photos considerably. In some programs, you can use a Shadows-Highlights function to improve your image. For GIMP, there is a plug-in yet GIMP's Curves...

Prerequisites for Scanning

Before you can read an image from a scanner in an image editing program in Windows, you must properly connect the scanner to your computer and install the scan program that came with the device. If you use Linux, you can use the XSane interface. What image editing programs generally do is provide a scanning connection usually referred to as the TWAIN source for the Windows platform and Scanner Access Now Easy SANE if you're using Linux or Mac OS . An independent scanning program or Xsane is...

Color Management

Color management, or color profiling, involves the color space of the different devices being used. The use of color profiles secures a constant rendition of colors between the various devices and various programs when you're editing a picture. For our purposes, sRGB is the standard color profile it is essential for cameras and monitors. This is the only color profile UFRaw offers. Other color profiles, such as Adobe RGB for printing purposes , can be found online. As soon as you save a color...

Editing a Scanned Image

Miami Tif Gimp

To help you practice the editing steps that follow, you'll find an image called miami.tif in the Sampieimages folder on the accompanying DVD. Open the file choose File gt Open in GIMP's Toolbox and save it as miami-impro in an exercise folder on your hard disk. Save the image in a high-quality file format, such as XCF or TIFF. After you open the file, you may notice a few defects. The image tilts to the right because it wasn't inserted properly in the scanner. In addition, the borders of the...

Base Curve

Ufraw Base Curve Tab

The base curve tab includes brightness and contrast settings. It imitates the functionality of Nikon's tone curves. Various camera manufacturers and other sources offer tonality curves on their websites. To load a curve that you've downloaded or created on your computer, click the folder icon above the curve editor. Some ready-made curves for Nikon and Canon are available on Udi Fuchs's website at http ufraw.sourceforge. net Colors.html. You can find curves from other manufacturers at http www....

Raw Therapee for Developing Raw Images

RawTherapee's program screen offers many options and seems a little cluttered at first. The program offers a row of functions that are available in GIMP but not in UFRaw. In RawTherapee, you can perform all the steps in 16-bit color depth per channel. RawTherapee's program screen offers many options and seems a little cluttered at first. The program offers a row of functions that are available in GIMP but not in UFRaw. In RawTherapee, you can perform all the steps in 16-bit color depth per...

Live Histogram

The histogram of the preview image is updated as the settings on the image are changed. You can right-click on the live histogram to set the curve's size and representation. There are two modes in which you can control the exposure. Clicking the controls or buttons underneath the live histogram will show you the overexposed and underexposed pixels in the image. Activate the check boxes by clicking them. The corresponding pixels will light up in the preview. Click each Indicate tab to view the...

Lightness Adjustments

The last of the corrective functions is Lightness Adjustments, new in UFRaw 0.16. It offers tools to fine-tune the lightness of up to three different colors, lightening or darkening the hue of the chosen color all over the image. Lightness is not brightness. The function doesn't brighten up the whole image, just the color tone you have chosen with the function's pipette. To start, click the eyedropper symbol in the function's tab window. A new line with a slide control and three buttons shows...

Interpolation

Interpolation defines how the image dots should be recalculated when you save the final image. The default is AHD interpolation. It provides the best results but may enhance the noise in the photo. VNG interpolation provides very good results. VNG four color interpolation should be used if you find Bayer pattern artifacts in your photo for other disturbing patterns, see section 2.4.3 and 2.5.7 . PPG interpolation is short for Patterned Pixel Grouping interpolation. This interpolation method is...

Exposure

You can digitally change the original photo exposure. Essentially, you can select the luminosity, or brightness of your picture, over the slide control in Exposure compensation in EV according to your own preference. Changing the luminosity of your exposure is rather simple. However, by changing the luminosity, you can also increase noise in the image noise is the random appearance of colored pixels throughout the picture . Decreasing Exposure is a little problematic because the highlights very...

WB White Balance

UFRaw always adjusts white balance when developing RAW photos. The white balance settings control the ratio between the three color channels As the default setting, UFRaw uses the white balance of the camera if possible. If the image meets your expectations after the white balance has thus been adjusted automatically, you can forgo further adjustments and apply the default settings. However, the white balance settings of cameras often could use some adjustment. Try to use some other settings...

JPEG versus RAW

If you are taking pictures not only during good weather, but also at dusk, at night, or with a flash, then JPEG is not the best format for good pictures. Photographs shot against the sun are problematic. Keep in mind that the JPEG format has a color depth of 24-bit approximately 16.8 million colors . The results are images in true color. Nevertheless, the lossy compression of this file format saves file space by blending areas of similar color. This reduces the amount of information that needs...

Where Can I Get GIMP

GIMP is a free program for image editing, designed and developed for the largely free Linux operating system. When Microsoft Windows users discovered GIMP, their interest motivated the development of a Windows version that has been available for several years now. The Windows version and additional helpers or plug-ins can be downloaded for free from the following locations. GIMP's home page is at http www.gimp.org. You'll find links to versions available for the Linux UNIX, Windows, and Mac OS...

The Image Window the Main GIMP Interface

Gimp Magnetic Pen Tool

The image window offers the possibilities to change GIMP's appearance and features. For example, you can use the Windows menu to choose windows that should be opened when the program is started. You close the program by clicking the red X in the upper-right corner of the empty image window or the Toolbox. The menus in the image window offer the most important options for working, for configuring the program to suit your needs, or simply for finding help. However, the most significant role of...

Converting Camera RAW Image Formats under Windows Mac OS X and Linux Freeware and Plug Ins

Highest Quality Format Gimp

If your digital camera uses a proprietary file or RAW file format to capture images, you should use it. Taking photos as digital raw data will result in a higher-quality image after correction, particularly when compared to photos taken in the highest-quality JPEG format. Saving images in their native camera or RAW format will also ensure that you'll get the best possible quality when you archive the originals. Since version 2.2.6, GIMP supports RAW formats, so you can directly open and edit...

GIMPs Program Windows

Gimp Windows Toolbox

When you first open GIMP, three separate windows appear on the desktop. The Toolbox or Tools palette with the tool settings, an initially empty image window, and a window called Dock with windows called dialogs for administrating layers and various other choices above the dock with the tabbed dialogs Layers, Channels,Paths, Undo, and below the dock with Brushes, Patterns, Gradients . These three dialogs are represented by tabs in the dock. Clicking a tab opens the corresponding dialog. However,...

Helpers Image Management Programs for Windows Mac OS X and Linux

If you need to comfortably manage large image collections, you can use an image viewer or image management program such as these for Windows ACDsee http www.acdsystems.com ThumbsPlus http www.thumbsplus.com CompuPic http www.photodex.com IrfanViewer free http www.irfanview.com XnView for Windows, Mac OS X and Linux free http xnview.com ImgSeek photo collection manager for Windows, Mac OS X, and Linux and ImgMagic http www.imagemagick.org The following program works under Windows and Mac OS...

Using the Operating Systems File Management Tools to Import Images from a Camera

Windows Digital Camera Import Wizard

Your computer's operating system offers options to import images from the camera to the computer. If you use the Windows platform, your computer probably came with an appropriate USB driver. Alternatively, you may have received a USB driver along with your camera typically on a CD packaged with it . However, if you do not have the driver, you can usually find one to download on your camera manufacturer's website. Windows here Windows 7 offers a wizard to import images from a camera. Windows...

Opening and Developing a RAW Format or Digital Negative with GIMP

GIMP can open most but not all RAW file formats offered by camera manufacturers. As a start, you can use GIMP for editing these images directly, but only with a color depth of 24 bits 8 bits per channel . However, if you want to develop your digital negatives with the original color depth of 16 bits per channel rather than 8 bits in order to make fine-tuned corrections and or print a higher-quality photo, you'll have to depend on the RawPhoto or UFRaw plug-in. Once you've integrated one of...

Opening an Image in UFRaw

When you start the stand-alone version of UFRaw, you'll see the window UFRaw you will use to open files. This window looks similar to the window in GIMP for opening an image using the File gt Open menu option. Windows users may need some time to get accustomed to it because this window looks somewhat different than the Open window in standard Windows programs. The window includes two panes. Double-click on the drive or main directory in the left pane, and then in the right pane, choose the...

Is GIMP Insecure Some Comments and Tips

Unfortunately, computer programs sometimes crash unexpectedly or react strangely. This can happen with any freeware running on Windows. Since GIMP is GNU software, there are no guarantees. In earlier versions of GIMP, I've experienced some bugs, but from version 2.0 onward GIMP has become very stable. In the event that something doesn't work, it is typically due to incompatibility with other installed software or a specific hardware problem. GIMP's current version, 2.6.10, runs on Windows Vista...