Compression methods
Distiller applies ZIP compression to text and line art, ZIP or JPEG compression to color and grayscale images, and ZIP, CCITT Group 3 or 4, or Run Length compression to monochrome images.
- A.
- ZIP
- B.
- JPEG
- C.
- CCITT
- D.
- Run Length
You can choose from the following compression methods:
- ZIP
-
Works well on images with large areas of single colors or repeating patterns, and for black-and-white images that contain repeating patterns. Acrobat supports only 8-bit ZIP compression, which is lossless; that is, data is not removed to reduce file size, so image quality is not affected.
Note: Adobe implementation of the ZIP filter is derived from the zlib package of Jean-loup Gailly and Mark Adler, whose generous assistance we gratefully acknowledge. - JPEG
-
Suitable for grayscale or color images, such as continuous-tone photographs. JPEG is lossy, which means that it removes image data and may reduce image quality; however, it attempts to reduce file size with the minimum loss of information. Because JPEG compression eliminates data, it can achieve much smaller file sizes than ZIP compression.
- CCITT
-
Available only for monochrome bitmap images. CCITT (Consultative Committee on International Telegraphy and Telephony) compression is appropriate for black-and-white images and any images scanned with an image depth of 1 bit. Group 4 is a general-purpose method that produces good compression for most monochrome images. Group 3, used by most fax machines, compresses monochrome images one row at a time.
- Run Length
-
Produces the best results for images that contain large areas of solid white or black.