-F filetype
The -F parameter determines the image file type that will be saved. If -F is not specified, the file type will be a Windows BMP file. If the -multipage option is used, the file will be a multipaged image file (only TIFF, PCX, PDF, and PostScript formats allow multi-page image files).
The valid values for -F are as follows:
bmp |
Windows BMP file |
emf |
Enhanced Windows meta-file format |
gif |
Compuserve GIF format |
ico |
Windows ICON format |
icov |
Vista compatible ICONs |
jpeg |
JPEG format |
jp2 |
JPEG-2000 format |
pcx |
PCX format |
Adobe PDF format |
|
png |
Portable Network Graphics (PNG) format |
psd |
Adobe Photoshop format |
ps1 |
PostScript Level 1 format |
ps2 |
Postscript Level 2 format |
tga |
Targa Format |
tif1 |
uncompressed TIFF image |
tif2 |
TIFF using PackBits compression |
tif3 |
TIFF using Group 3 Fax compression |
tif4 |
TIFF using Group 4 Fax compression |
tif5 |
TIFF using JPEG compression |
tif6 |
TIFF using Flate compression |
tif7 |
TIFF using LZW compression |
wbmp |
Wireless Bitmap |
wmf |
Windows Meta File. |
Example: Acquire to a Group 3 TIFF format, the file is called mytif.tif:
twainsave -F tif3 -f mytif.tif
If the device cannot save to the file type specified, this will usually mean one of the following:
| • | There was a general problem in saving the file (disk full, user does not have write access to the drive and directory, etc.) or |
| • | TWAIN device did not or could not acquire the image in the proper format. For example, a Group 3 TIFF is specified (-F tif3), however the device acquired a color image. Color images cannot be saved to Group 3 or Group 4 TIFF files. You would see the following in a command-line window if the -verbose option is specified, or in the log file specified by -verboselog: |
The error states that the device is attempting to transfer 8 bit images (usually color or gray scale), but the image format specified (TIFF Group 3) does not support color or gray-scale images.
If the device's user interface is shown, the user may have chosen an incorrect type that matches the format given on the TwainSave command line. Therefore it is highly recommended that if you plan to use TwainSave, and the device's user interface will be available to the user, to select a file format that gives you the most supported types of colors. For example BMP supports both monochrome, gray-scale, and color images, as do all forms of TIFF except for Group 3, Group 4 TIFF, and TIFF-JPEG.
Here are the list of file types, and the bits-per-pixel supported for each one:
Below is a table describing the valid bit-depths for each file type:
File Type Bit Depth
bmp |
Any bit depth |
ico* |
8, 16, or 24 |
jpeg, jp2 |
8, 16, or 24 |
pcx |
1, 8 or 24 |
tga |
8 or 24 |
tif1, tif2, tif5, tif7 |
1, 4, 8, 16, or 24 |
tif3, tif4 |
1 |
tif6 |
8, 16, 24 |
emf, wmf |
24 |
gif |
1, 8 |
png |
1, 8, 16, or 24 |
psd |
24 |
1, 8, 16, 24 |
|
ps1, ps2 |
1, 8, 16, 24 |
wbmp |
1, 8, 16, or 24 |
1 bit-per-pixel are monochrome (black/white) images.
4 bits-per-pixel are usually gray-scale images.
8 bits-per-pixel are usually gray-scale and 256 color images.
16 and 24 bits-per-pixel are usually color images.
Note: Bit depths higher than 24 should be stored as bmp files.
* Non-Vista Windows ICON format is limited to images that have widths and heights less than 256 pixels. Therefore ICO image file generation may require the -thumbnail option to scale the image to fit the ICO size limits.
Default Setting:
The image type is bmp (Windows BMP).