Image Formats
| Format Extension |
File Format |
MultiPage/ Color-Gray Support |
Compression Options |
Advantages |
Disadvantages |
|---|---|---|---|---|---|
| TIF | Tagged Image File Format (TIFF) | Yes/Yes | CCITT Group 4 CCITT Group 3 Modified Group 3 JBIG Enhanced JBIG JPEG Packbits ZIP WANG JPEG None |
Handles black-and-white, grayscale, and color images well. Supports multiple images per file. Works across multiple platforms. Available in most commercial imaging applications. TIF with JBIG compression provides the best binary and grayscale file compression. TIFF with JPEG compression provides excellent color file compression. | So flexible that many implementations are not complete, so TIFF files from one application may not be compatible with another application's implementation. Format also allows for private, undisclosed data field formats making certain implementations closed to other applications. |
| TIF | Plexus TIFF | No/Yes | CCITT Group 4 CCITT Group 3 Modified Group 3 Packbits None |
Compatibility with Plexus imaging systems. | Only support a subset of the regular TIFF features. |
| PCX | ZSoft PC Paintbrush | No/Yes | RLE | Widely supported on PC platforms. Supports black-and-white, grayscale, palette color and 24-bit color images. Reasonably efficient storage of images with large areas of constarnt tone. Images are always compressed using run-length encoding. | Run-length encoding is inefficient for storing typical scanned images. Produces files twice the size of TIFF packbits. Generally not supported on non-PC platforms. |
| DCX | ZSoft PC Paintbrush FAX extension | Yes/No | RLE | Same as PCX but black-and-white only. Supports multiple images per file. | Same as PCX |
| BMP | Microsoft Windows Bitmap | No/Yes | None RLE for some color formats |
Wide support under Microsoft Windows. Handles black-and-white, grayscale, palette color and 24-bit color images. | Poor support outside of Windows. Poor support of compressed files. Does not support multiple images per file. |
| JBG | JBIG | No/Gray | JBIG Enhanced JBIG |
Excellent binary and grayscale compression. | No support for color. Not widely supported at this time. |
| JPG | JPEG JIFF | No/Yes | JPEG | By far the best compression for photographic images. | Many incompatible implementations. Lossy, meaning that color and image data is discarded to save storage space at the expense of image qualities that typically are below the threshold of human vision. |
| PDA | Calera Processed Document Architecture | No/No | CCITT Group 4 CCITT Group 3 None |
Single file format can contain bitmap image data or text. Very good compression is possible. | Very little support other than Caere applications (WordScan, M/Series Professional). No color support. (Developed for OCR applications.) |
| Portable Document Format (Adobe Acrobat) | Yes/Yes | CCITT Group 4 CCITT Group 3 ZIP |
Compatibility with Adobe Acrobat. | Different types of the PDF files can be easily confused. | |
| PNG | Portable Network Graphics | No/Yes | ZIP | May become a replacement for GIF as the standard web graphics format. Superior to GIF because it also supports binary and 24-bit color. | Not widely supported at this time. |
| MDA | IBM MO:DCA | Yes/Yes | CCITT Group 4 JPEG None |
Compatibility with IBM imaging systems. |
Binary images can acheive a compression ratio of a 35:1 to 50:1 compression ratio, depending on the characteristics of the image.