the Compression Preference is invalid.| Example-VB | Example-VC++ |
Sets all compression options, based on the input Image type.
| Ö | Imaging for Windows Professional Edition V1.0, V1.1, and V2.0 |
| Ö | Imaging for Windows 98 |
| Imaging for Windows 95 | |
| Imaging for Windows NT 4.0 |
Note: The ImageType, CompType and CompInfo parameters are ignored unless the CompPreference parameter 3 (Custom) is chosen. Each parameter, however, must have a value set.
Image Scan control
object.SetPageTypeCompressionOpts CompPreference,ImageType,CompType,CompInfo
CompPreferenceConstants (Integer)
| Constant | Setting | Description |
| BestDisplay | 0 (default) | Best display quality |
| GoodDisplay | 1 | Good display quality, small file size |
| SmallestFile | 2 | Smallest file size |
| CustomSettings | 3 | Custom settings |
ImageTypeConstants (Integer)
| Constant | Setting | Description |
| BlackAndWhite1Bit | 1 | Black and white |
| Gray4Bit | 2 | 16 shades of gray |
| Gray8Bit | 3 | 256 shades of gray |
| ColorPal8Bit | 4 | 256 colors |
| TrueColor24bitRGB | 5 | True color (RGB 24 bit) |
| ColorPal4Bit | 6 | 16 Colors |
CompTypeConstants (Integer)
| Constant | Setting | Description |
| Uncompressed | 0 | uncompressed |
| CCITTGroup31D | 1 | CCITT Group 3 1D |
| CCITTGroup42D | 2 | CCITT Group 4 2D |
| TIFFPackbits | 4 | TIFF Packbits |
| JPEGCompression | 8 | JPEG |
| LZWCompression | 21 | LZW |
CompInfoConstants (Integer)
| Constant | Setting | Description |
| NoCompInfo | 0 | No compression information |
| G31DModifiedHuffman | 4096 | Group 3 1D Modified Huffman |
| G31DModifiedHuffmanRBO | 0 | Group 3 1D Modified Huffman with reversed bit order |
| G31DFax | 6400 | Group 3 1D Fax |
| G31DFaxRBO | 2304 | Group 3 1D Fax with reversed bit order |
| G42DFax | 4608 | Group 4 2D Fax |
| G42DFaxRBO | 512 | Group 4 2D Fax with reversed bit order |
| TIFFPackbitsInfo | 0 | TIFF Packbits (no compression information) |
| LZWInfo | 0 | LZW (no compression information) |
| JPEGLowLow | 11610 | JPEG low resolution, low compression |
| JPEGLowMed | 7740 | JPEG low resolution, medium compression |
| JPEGLowHigh | 3870 | JPEG low resolution, high compression |
| JPEGMedLow | 27994 | JPEG medium resolution, low compression |
| JPEGMedMed | 24124 | JPEG medium resolution, medium compression |
| JPEGMedHigh | 20254 | JPEG medium resolution, high compression |
| JPEGHighLow | -21158 | JPEG high resolution, low compression |
| JPEGHighMed | -25028 | JPEG high resolution, medium compression |
| JPEGHighHigh | -28898 | JPEG high resolution, high compression |
An error occurs when
the Compression Preference is invalid.
the Image Type is invalid.
the Compression Type does not match the Image Type.
the Compression Info does not match the Compression Type.
The relationship between Image Types, Compression Types, and Compression Info is shown below.
Black and White
| Uncompressed No compression information |
| CCITT Group 3 1D
Group 3 1D Modified Huffman |
| TIFF Packbits TIFF Packbits (no compression information) |
16 Shades of Gray
| Uncompressed No compression information |
| LZW (Professional Edition only) LZW (no compression information) |
256 Shades of Gray
| Uncompressed No compression information |
| LZW (Professional Edition only) LZW (no compression information) |
| JPEG |
| JPEG Low resolution, Low compression JPEG Low resolution, Medium compression JPEG Low resolution, High compression JPEG Medium resolution, Low compression JPEG Medium resolution, Medium compression JPEG Medium resolution, High compression JPEG High resolution, Low compression JPEG High resolution, Medium compression JPEG High resolution, High compression |
256 Colors
| Uncompressed No compression information |
| LZW (Professional Edition only) LZW (no compression information) |
True Color (RGB 24-bit)
| Uncompressed No compression information |
| LZW (Professional Edition only) LZW (no compression information) |
| JPEG |
| JPEG Low resolution, Low compression JPEG Low resolution, Medium compression JPEG Low resolution, High compression JPEG Medium resolution, Low compression JPEG Medium resolution, Medium compression JPEG Medium resolution, High compression JPEG High resolution, Low compression JPEG High resolution, Medium compression JPEG High resolution, High compression |
16 Colors
| Uncompressed No compression information |
| LZW (Professional Edition only) LZW (no compression information) |