ImageGear v26.5 - Updated
Developer Guide / File Formats and Compressions / Compressions / JPEG Compressions / Progressive JPEG Compression
In This Topic
    Progressive JPEG Compression
    In This Topic
    Full Name Progressive JPEG Compression
    Compression ID ImGearCompressions.JPEG = 6
    ImageGear Assembly ImageGear.Core Assembly
    Bit Depth Gray level: 8, 16 bpp; RGB: 24, 36 bpp; CMYK: 32 bpp; RGB+Alpha: 32 bpp
    File Formats JPEG

    Comments

    Progressive JPEG is considered an extension to the JPEG standard. It produces the same kind of lossy compression as normal JPEG compression (see above), except that it saves multiple copies of the same image using different levels of quality. There is no hard limit on the number of "scans" that may be stored.

    When a Progressive JPEG-compressed image is decompressed, the filter decompresses the lowest quality image first. This can be helpful for quickly displaying a version of the image that you are loading. The benefit of this compression is the fast display of an image that is recognizable. The downside is that a JPEG decompression is performed more than once.