You can use the IMACRT call to create a device or application image. In
the example, the IMACRT at B creates a scanner device image that
receives the image data from the scan of the document. This scanner image
is the source of the impending transfer operation.
The parameters have the following meanings:
- The first parameter is the identifier of the image. You use image
identifiers when creating images, and when transferring data between
images. You always use the identifier -1 for a scanner device image.
You use positive values for application images. The display device
image (identifier 0) cannot be created using this call, but you can
use the ISFLD call (define an image field) to create an image with
identifier 0.
- The second and third parameters specify the horizontal and vertical
size of the image, in pixels. The example is written assuming that
documents to be scanned are 6 inches horizontally, and 4 inches
vertically. You have a choice of three pairs of defined resolutions
on the 3117 and 3118 scanners.
This program uses 240/240, so the size of the image in pixels is fixed
at 6 x 240 = 1440 horizontally, and 4 x 240 = 960 vertically.
- The fourth parameter, 0, indicates default image type, meaning this is
a bi-level image.
- The fifth parameter indicates whether or not the image is to have a
defined resolution.
The value 1 indicates that a resolution for the image will be defined
in the next three parameters. (A value of 0 is used for raw image
data, for example a computer-generated array of pixels, of no
particular physical size.)
- The sixth parameter specifies the units used to define the resolution
of the image in the last two parameters:
- 0
- Inches
- 1
- Meters
- The last two parameters specify horizontal and vertical resolution, in
this case both 240 pixels per inch.
So, now that the program has created the scanner device image, it is ready
to scan the document.
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GDDM V3R2 Base Application Programming Guide
Copyright IBM Corporation 1990, 2012