Full Name	Xerox 9700 graphic image (IMG)
Format ID	IG_FORMAT_XRX = 46
File Extension(s)	*.img
Data Type	Raster Image
Data Encoding	Binary
ImageGear Multipage Support	No
ImageGear Alpha Channel Support	No
ImageGear Platforms Support	WIN32, WIN64, Unix, Unix64, .NET, .NET64, MAC

ImageGear Supported Versions:

Version 1.0

Version 2.0

ImageGear Supported Features:

• IG_FLTR_DETECTSUPPORT - autodetection
• IG_FLTR_PAGEREADSUPPORT - single page file reading

ImageGear Read Support:

• IG_COMPRESSION_NONE - Indexed RGB: 1, 8 bpp

ImageGear Write Support:

None

ImageGear Filter Control Parameters:

None

Comments:

The IMG header contains the width, height and resolution of the image. Following the header is compressed data. The sample values of a binary image are compressed and then encoded into a sequence of bits. Compression is achieved by predicting a pixel value based on pixel values that have already been computed. For example, the predicted value of a pixel may be that of the corresponding pixel on the previous scan line. Up to fifteen different compression techniques are used, each designed to remove redundancy from a certain kind of image - text characters, line art, and halftones of various screen frequencies. The algorithm adapts to the properties of the image by selecting the technique that will perform the best.

References Used

Xerox System Integration Standard. Raster Encoding Standard. Xerox, XNSS 178506, June 1990.