User Guide

Academic Courseware: Chapter 6

Joyce Ryan

The compression ratio is inversely proportional to image quality. The

Quality slider allows you to set an optimum level between the amount

of compression and image quality. For most work in Corel Painter, you’ll

want Quality set to High.

Animation

This compression method works well with areas of continuous tone. If

you set Quality to Best and make every frame a key frame, this

compressor is lossless. For most Corel Painter animations, this

compressor is a good choice.

Cinepak

This method produces acceptable motion and image quality at

remarkably small file sizes. It is the preferred format for CD-ROM

delivery and transfer across the Internet. Cinepak can take a long time

to compress, and it can be difficult to find the best compression settings

for certain image types and frame rates.

Graphics

This method is limited to 256 colors. It compresses the file at a greater

ratio than the Animation compressor, but does not play as quickly.

None

With this setting, no compression is used, so the images retain all of

their quality. With a large frame size, some computers might not be fast

enough to play at a high frame rate.

Photo-JPEG

JPEG is an international standard for image compression. It allows high

compression ratios while maintaining excellent image quality. However,

it does not play at high rates.

Video

This method is designed for recording and playing back digitized video

at high rates. Because of the spatial compression method it uses, the

Video compressor does not provide great results for images with large

areas of continuous tone, such as those in most animations.

Codecs make use of different

techniques to compress images. Some are

“lossy,” meaning that they lose data to

make the files smaller. The JPEG

format is lossy. This is a great format

for the Web, allowing you to choose the

amount of loss you are willing to

accept. However, you should never save

a JPEG twice. Each time the file is

resaved, it will lose more data. Be

aware of whether you are saving your

work with lossy or lossless compression

and choose wisely.