ImageGear .NET v25.2 - Updated
Developer Guide / File Formats and Compressions / File Formats / File Formats Reference / IMG
In This Topic
    IMG
    In This Topic
    Full Name Xerox 9700 graphic image (IMG)
    Format ID ImGearFormats.IMG
    File Extension(s) *.img
    Data Type Raster Image
    Data Encoding Binary
    Multi-Page Support No
    Alpha Channel Support No
    Metadata Update Support No
    ImageGear Platforms Support WIN32, WIN64, Unix, Unix64, .NET, .NET64, MAC

    ImageGear Supported Versions

    ImageGear Supported Features

    ImageGear Read Support

    ImageGear Write Support

    No

    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.