calculate quality from compression level

selaux / node-sprite-generator

Generates image sprites and their spritesheets (css, stylus, sass or less) from sets of images. Supports retina sprites. Provides express middleware and grunt task.

MIT License

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calculate quality from compression level #9

Closed selaux closed 11 years ago

selaux commented 11 years ago

This will calculate the quality parameter for graphicsmagick from the compression level.

Input: 0-9 Output: 10-100

johnyanarella commented 11 years ago

Looks like with that equation, the transformed result is flipped:

options.compressionLevel	10 * (10 - options.compressionLevel)	(options.compressionLevel * 10) + 10
0	100	10
1	90	20
2	80	30
3	70	40
4	60	50
5	50	60
6	40	70
7	30	80
8	20	90
9	10	100