. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343 14.7.16 Save to Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343 the ‘Layer’ menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 394 14.10.41Add Alpha Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 395 14 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 396 14.10.46Add Alpha channel to Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 397 14

QuickMask . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 464 16.4.18 Save to Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 464 16.4.19 To Path . . . . . . . . . . 544 16.7.33 Add Alpha Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 545 16.7.34 Remove Alpha Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 547 x CONTENTS 16.7.39 Add Alpha channel to Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 547 16.7.40 Subtract from

Colorcube Analysis 291 Chapter 18: Image Menu: Channel Ops And Alpha.................................................................... 293 The Channel Ops Menu 294 Alpha 303 Chapter 19: Select disk space • Sub-pixel sampling for all paint tools for high-quality anti-aliasing • Full Alpha channel support • Layers and channels • A procedural database for calling internal Gimp functions from airbrush, clone, convolve, blend and text • Effects filters (such as blur and edge detect) • Channel and color operations (such as add, composite and decompose) • Plug-ins that allowed for the easy

space • Sub-pixel sampling for all paint tools for high-quality anti-aliasing • Full Alpha channel support for working with transparency • Layers and channels • A procedural database for calling be represented as a combination of red, green, and blue, RGB images are full-color. Each color channel has 256 possible intensity levels. More details in Color Models In a grayscale image, each point and one blue. Actually, both RGB and grayscale images have one additional color channel, called the alpha channel, representing opacity. When the alpha value at a given location in a given layer is

not ethically acceptable for publication! Alpha channel • Alpha channels are masks through which you can display images • Within an alpha channel: – White acts as the visible area – Black acts as alpha channel? 0 50 100 150 200 250 0 50 100 150 200 250 In GIMP – Layer > Transparency > Add Alpha Channel Colour to Alpha Channel • You can assign a colour to the alpha channel, which Specify file format e.g. PNG • Always save your image as a PNG file, maintains transparency (alpha channel) and is lossless

and blue are referred as channels of the image. In addition to the colour channels, the alpha channel is used to store the opacity of the pixels. (Opacity ranges from fully transparent to fully opaque having 8 bits in each channel. Some image formats, such as BMP and PNG, allow the use an additional 8 bits to store the alpha channel. Grayscale images, having only one channel, usually have a colour description. Below the tools there are the options for the selected tool.  The “Layers, Channel, Paths, Undo” window. These are the features that make GIMP and other image editing software

scissors, fuzzy selection by color, and even bezier selection. The program supports a full host of channel operations and many types of displays from 8 bit to 24 bit. Newer beta versions of the program support padding around it: Image A We'll label this first padded image Image A. Now execute "Filters->Channel Ops- >Duplicate." Note that you get a copy of Image A. We'll use that copy later. The first version and it will be filled with solid black: Image B We're halfway done. By executing "Filters->Channel Ops->Offset" on Image B and selecting an X and Y displacement of about 20 pixels in each direction