Class that represents a collection of capabilities (compression) supported by device. Use JpegQuality capability as a shortcut to select JPEG quantization tables that tradeoff quality versus compressed image size. Used in concert with DAT_JPEGCOMPRESSION it is possible for an Application to obtain the tables that are appropriate for varying percentages of quality within a given Source. TWJQ_UNKNOWN is a read-only value (get or getCurrent), the Application cannot set the Source to this value. This value is reported if the Application uses DAT_JPEGCOMPRESSION to select the quantization tables, and the Source is unable to resolve those tables to a percentage value. The next three TWJQ_ values are intended as markers into the quality range, and are only applicable with set method. get, getCurrent and getDefault only return values in the range 0 - 100. If an Application wishes to map a TWJQ_ value to a corresponding value in the range 0 - 100, then it must issue a get after a set with one of the three TWJQ_ values. No assumption is made about the meaning of the range 0 - 99, it may be derived from the JPEG standard or it may be optimized for the Source's device. 100, though, implies a lossless form of compression. Applications are not encouraged to use this value since it results in poor compression, as well as a format that is not currently widely supported in the industry. TWJQ_UNKNOWN - read-only; must be the setting for this capability if the user sets the JPEG compression tables using DAT_JPEGCOMPRESSION, and the Source is not able to map the selected tables to a specific percentage of quality. TWJQ_LOW - write-only; implies low quality; the images are at the maximum compression recommended by the Source. TWJQ_MEDIUM - write-only; implies medium quality; the images are at the balance point between good compression and good images. This is an arbitrary setting on the part of the Source writer that is expected to best represent their device. This is the value that Applications are most encouraged to use. TWJQ_HIGH - write-only; implies high quality; the images display the maximum quality that produces any kind of meaningful compression. Note that images at this setting are still considered to be lossy.

public class Compression : CapSetBase

Public Class Compression
	Inherits CapSetBase

public ref class Compression : public CapSetBase

type Compression =  
    class
        inherit CapSetBase
    end