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Image, Audio, and Video Extenders Administration and Programming


Image conversion options

The following table lists the conversion options (in addition to format conversion) that you can specify for an image when it is stored, retrieved, or updated. The Image Extender applies your specifications to the target image; the source image is not changed.

Each conversion option is specified as a parameter/value pair. The allowed values for each parameter are listed in the table.

Table 5. Image conversion options
Parameter Description Value
-b Number of bits used to represent each image sample 1 or 8 bits
-s4 Scaling factor Any decimal value greater than zero. The scaling factor specifies the size ratio of the converted image to the original. For example, a scaling factor of 0.5 converts the image to half of its original size. A scaling factor of 2.0 converts the image to twice its original size.
-p Photometric (image inversion). This option changes the interpretation of an image, based on the value specified. It does not change the image itself. This option applies to black and white or grayscale images only, and does not apply to images in GIF format.
0 = Ones are black
1 = Ones are white

-n Photometric (image inversion). This option changes an image by inverting black to white, and white to black. The option applies to black and white or grayscale images only. None
-r4 Rotation
0 = 0 degrees (no rotation)
1 = 90 degrees (counterclockwise)
2 = 90 degrees (clockwise)
3 = 180 degrees

-x4 Width in pixels Number of pixels
-y4 Height in pixels Number of pixels
-c Compression type
0 = IBM MMR
1 = CCITT Group 3 1-D
2 = CCITT Group 3 2-D (k=2)
3 = CCITT Group 3 2-D (k=4)
4 = CCITT Group 4
6 = TIFF Type 2
10 = Uncompressed
14 = LZW
15 = TIFF Packbits
25 = JBIG


Footnotes:

4
If you specify this option for an interlaced GIF image, you should also specify a compression type of LZW.


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