User`s guide

Image Transfer

The Image Transfer dialog box contains settings for the image

data being transferred from the HHP imager engine to the ISC-

Imager Demo Application and allows the user to select the

image window size, the pixel sub-sample value and the transfer

compression type.

Image Window: The upper left and lower right X and Y

coordinates define the size of the image to transmit (before

sub-sampling). Default is VGA – 640 by 480 pixels.

Histograph Stretching: When Histo Stretch is enabled,

the image contrast is enhanced (histogram stretch and

median value shift).

Pixel Subsample: Image data within the image window

can be sub-sampled. Valid sub-sample range is 1 (no sub-

sample) to 10. Default is 1.

Transfer Compression: An image can be transferred

uncompressed, losslessly compressed (Adaptive Huffman Encoding) or with JPEG lossy compression.

If the Transfer Compression is set to JPEG Lossy, the JPEG Quality spin control becomes active. It

allows you to set the level of JPEG compression in terms of the "quality" (resultant degradation) of the

image. A quality value of 100 means a virtually lossless transfer, but provides only 2:1 compression

while a value of 1 results in a poor image with compression ratios of up to 100:1.

Save Image As Format/View

The Save Image As Format/View menu includes two Image Format dialog boxes. The View Orientation

box allows the user to specify the Normal View (Default) or an Upright View. The images captured by the

imager have an aspect ratio of 4:3 while the display of most (if not all) Pocket PC PDA/PDT’s is 3:4. The

application default (Normal View) is to display the captured image rotated counterclockwise 90° so that the

maximum amount of the image is displayed. The user may choose to display the image right side up.

However, when Upright View is enabled, the image received will also be cropped to fit the display, and the

left and right edges of the image are lost.

The Image Save As Format box allows the user to select what file format a captured image is saved in. If the

Raw Grayscale image format is selected, the image cannot be saved. The three save formats are: Bitmap

Grayscale (bmp), JPEG Grayscale (jpg) or TIFF Grayscale (tif). If the JPEG Grayscale format is selected, the

user may also specify an image quality factor. The Image Save As Format maintains a selected setting until

changed by the user.