User Guide

28 Corel Painter User Guide
• The Progressive JPEG check box creates a progressive JPEG file. Progressive
format is useful for files used on the Web. As the name implies, progressive format
displays an image in stages — as a series of scans — while the file downloads. The
first scan is a low-quality image; the following scans improve in quality. This allows
the user to see the whole image very quickly.
• The HTML Map Options — NCSA Map File, CERN Map File, and Client Side
Map File — let you generate an image map. (NCSA refers to the National Center
for Supercomputing Applications, and CERN refers to the Conseil Europeén pour
la Recherche Nucléaire.) Use the NCSA Map File or CERN Map File option to
generate a server-side image map. Use the Client Side Map File option to generate
a client-side image map.
Refer to “Working with Image Maps” in the Help for more information about image
map types.
It is best not to decompress and recompress a file multiple times. Although JPEG can
compress and discard data not visible or obvious, the degradation of the data can affect
the condition of your file.
When a file has lost a significant amount of data, block patterns may appear in areas of
the image. If you try to use the Apply Surface Texture feature on a JPEG file, you may
find it will accent the block patterns.
Saving GIF Files
Corel Painter allows you to save documents as GIF files. GIF, a file format using 8 or
fewer bits, is commonly used to display graphics on the Web. When you save a GIF
file, you can choose settings from 4 Colors to 256 Colors. You can choose how your
colors will be displayed and what part of your image will be transparent.
You can enable the Color Set option to force all colors in the color table of the GIF file
to match the colors in the current color set. This option can be useful when you are
doing Web work, especially if you want to constrain colors to a specific color set or
control the number of colors in a Web page, thus controlling the image file size.
The Imaging Method setting determines how your 24-bit Corel Painter document will
be converted to the limited number of colors that GIF uses. If you choose Quantize to
Nearest Color, Corel Painter picks the color nearest to that of each pixel. If you choose
Dither Colors, Corel Painter applies a pattern to the colors chosen to generate a more
accurate, less banded result.
Corel Painter can also save a frame stack as a GIF animation file. For more
information, refer to “Creating Animated GIFs” in the Help.