User Guide

Academic Courseware: Chapter 1
Joyce Ryan
11
in the graphic until you find the minimum number of colors
necessary for adequate display of your image on a Web page.
4 Choose an Imaging Method. Choose Quantize To Nearest Color if
you want Corel Painter to look at each pixel for which it doesn’t have
the exact color and pick the nearest color for it from the available
colors. Choose Dither Colors if you want Corel Painter to apply a
pattern to the colors chosen to generate a more accurate, less banded
result. In this case, Corel Painter will approximate the color of a
larger area of the image, rather than individual pixel colors.
5 You can now either save the graphic to use it on a Web page, or
return to Corel Painter to continue working on the image.
Resolution for video
In Corel Painter, when we start a new file, we see a dialog box that
requires us to enter a resolution in pixels per inch (PPI), or pixels per
centimeter. These pixels represent the number of blocks per inch making
up the grid of the bitmap. In video, the default screen resolution is 72
ppi. In addition, it is critical to know the width and height, or spatial
resolution necessary for the format you are working in.
Resolution for print
The RGB model can describe 256 levels of gray. Remember those gray
scales you did? How hard it was to create a gray scale with ten steps,
with twenty? Look at this grayscale strip—it is made of 256 levels of
gray. Can you tell the difference between all 256 shades of gray?
Most job printing presses can’t reproduce much more than 100 levels of
gray. Fine printers can do better if they use top quality materials and
papers, and highly controlled press conditions.