qlt qlt

JPEG quality. Specifies JPEG encoding attributes to control the compression level. This in turn varies the file size (amount of the reply data), and, indirectly, the visual quality of the resultant image.

qlt= *quality*[, *chroma*]

quality
JPEG encoding quality (1…100 int).
chroma
JPEG chromaticity down-sampling (0=normal, 1=disable); optional, default is 0.

Higher quality values increase file size and quality, lower values decrease file sizes and reduce perceived image quality. Values above 90 often generate images indistinguishable from the uncompressed image.

Set the chroma flag to disable the RGB chromaticity down-sampling employed by typical JPEG encoders. This may increase the perceived sharpness of edges in an image when the edge is defined by a change in hue rather than brightness. Setting this flag may cause a slight increase in file size. Experiment with this setting if text seems slightly blurry.

Properties section-925a44cbdc9042db8d4eb149cd073d21

Request attribute. Applies regardless of current layer setting. Ignored if the output image file format does not support JPEG encoding. Refer to the description of fmt= for information on which output image formats support qlt=.

chroma is ignored if the output pixel type is CMYK or gray.

Default section-0d8aa45d84df49e6b846596bbaf7f740

attribute::JpegQuality

Example section-d7d33871d401433aa51d028823eae7a9

Reduce quality for faster transmission over a low-bandwidth connection:

http://server/myRoodId/myImageId?qlt=60&wid=300

Increase quality for high-bandwidth connections:

http://server/myRootId/myImageId?qlt=95,1&wid=300

See also section-0074a060bb314ddfa7f4ed23be976507

fmt= , attribute::JpegQuality

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