Flash Templates Tutorials - SAVING FILES IN GIF AND JPEG FORMATS - Saving in GIF format
Saving in GIF format
To save a colored images in GIF format, you should convert it to the RGB color model by using Image > Mode > RGB, and then use Image > Mode > Indexed Color.
NOTE. The main property of the indexed image saved in GIF format is the ability to paste the transparent areas without creating new layers.
Here you may indicate the most important colors, choose colors from more natural palettes and apply transparency. Consider the options listed in the dialog box, and the impact on its image.
Palette tab allows you to select colors calculating method via the lookup table. There are following modes:
* Exact. It is used by default, if the image contains less than 256 colors (in case it is of high contrast or black and white);
* System. It is presented in two versions: Windows and Mac OS. It is used to create backgrounds, wallpapers or other elements of the desktop;
* Web. It is used by browsers; it is applied to display an image at the monitor. It includes those 216 colors, R, G and B values of which are divided into 51 integrally, that is, this 216 - color LUT table is the intersection of the sets of color palettes of Windows and Macintosh systems;
NOTE. LUT table (lookup table) is the table of looking for a color, it is generated by PhotoShop. It is a meaningful pointer or index, so the process is called indexing.
* Uniform. It is creating a homogeneous distribution of the spectrum colors. It is no longer used;
* Local. It is used when working with picture images when you need a high quality color. There are three types of reducing number of colors algorithms in this mode:
o Perceptual. It creates a customized color lookup table, giving priority to those shades, which are clearly distinguished by the human eye;
o Selective. It creates color lookup table similar to perceptual one, however it is based on the key colors of the image. Preference are given to web colors;
o Adaptive. It creates a customized table of those spectrum colors that are dominant in the image. It ignores all system palettes as well as the web palette;
NOTE. The most acceptable results are usually achieved by the mode Local (Adaptive).
# Master. Becomes available when two or more files are opened simultaneously. It is used to create a color lookup table which contains the colors of all open images. It is used for image package processing that can be later recorded on CD-ROM or other media. It works at the same algorithms of reducing color numbers as Local mode;
# Custom. It allows the user to create a lookup table by himself or to download it from the disk. It is used when creating images for multimedia applications, is not applied in web graphics almost. When selecting this mode there is dialog box Color Table appeared, where you can choose the following options:
* Custom - provides the possibility to create the table by yourself;
* Black Body - destroys the colors of blue and green part of the spectrum, leaving black, red, orange, yellow and white.
* Grayscale - image becomes a halftone;
* Spectrum - leaves only spectrum colors;
* System - Windows or Mac OS system table;
# Previous. This mode uses the last lookup table created by Indexed Color action. After using Master mode, the Previous mode becomes the default mode. It is suitable with creating multiple images matured in the same style.
NOTE. Prior to the application of Indexed Color action the Previous mode is unavailable in the current session.
ATTENTION. After transferring the image into Indexed Color mode, it can not be edited. Most of the tools and actions do not work or do not work properly, as was expected.
By changing Colors property, we can select the number of colors to use. The fewer colors are used, the smaller file size you will get.
Forced property allows entering some of the colors into the table forcibly. They do not change when choosing the remaining colors.
* None - the predefined colors can not be entered into the table. For colors formed on the basis of image, there are more positions in the palette;
* Black and White - there will be black and white colors in the palette at any case;
* Primaries - there are eight basic colors in the palette: black, white, red, green, blue, light blue, dark red and yellow;
* Web - the palette will contain 216 colors of the web palettes.
Transparency checkmark allows saving the transparent areas of the image. To define them, select one color from the palette. Note: as transparency is designated with one color, then the smooth change of pixels transparency within the Indexed Color mode is not possible. Options is the second group of properties.
Matte property is available if there is some transparency, and is used in conjunction with Transparency checkmark. If this mode is checked, then the set color will fill both hemi-translucent and transparent pixels.
NOTE. Select the color that corresponds to the web page background.
Dither property defines the style of removing of 'extra' colores. The distortions arising from the dithering are most noticeable when using the web palette. Since we do focus on web graphics, let's consider the dither modes.
* None - does not control the appropriate color rendering, it is suitable for "simple" images without shadows and smooth tonal transitions;
* Diffusion - distributes colors on special algorithm which doesn’t create a pattern and dither transitions between the different colors;
* Pattern - dithers colors with the help of a geometric pattern (this pattern may appear quite accurately at the final picture;
* Noise - mixes pixels of the whole image chaotically, without creating a pattern.
Amount property is available in case of using Diffusion mode, and it allows you to control its degree. The lower the value is, the lower the number of colors is used in the image, thus, the file size is smaller.
Preserve Exact Colors checkmark is available in case of using Diffusion mode, and preserves areas of the same color undithered.
Checking Preview mode allows evaluating results without leaving the dialog box.