To maintain the compression options already set in the registry. (The information returned is read but not interpreted.)| Example-VB | Example-VC++ |
Returns the compression information used by the specified image type. Applications can then request and save this information for future use.
| 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 |
Image Scan control
object.GetPageTypeCompressionInfo(ImageType)
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 |
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 |
The information returned by this method can be used as follows.
To maintain the compression options already set in the registry. (The information returned is read but not interpreted.)
To interpret compression information, and then use that information to set explicit compression options during runtime.
An error is returned if the ImageType is invalid.