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 Azalea Society of America | profile | all galleries >>  JPEG compression... >>  image miscellany... tree view | thumbnails | slideshow

 image miscellany...

This gallery explores the effects of adjusting image levels, image sharpening and JPEG compression. The first image is the original, at some unknown degree of JPEG compression; the second image is upsized to 640 x 480 pixels, level-adjusted, sharpened and saved at 40% quality.

The first series shows the effect of changing the degree of JPEG compression, shown here as quality levels from 30% to 100%, where 100% is no compression and thus the highest quality.

The second series shows the effects of editing the image levels by setting the black and white points to the edges of the histogram, and then saving it at 40%, 50% and 60%.

The final series shows the effects of also sharpening it, and then saving it at 40%, 50% and 60%.
original image
original image
o6%2f85%2f190885%2f1%2f80300530.8iTSc1Ey.palegreenspacer.GIF o6%2f85%2f190885%2f1%2f80301246.ci5NY75p.palegreenspacer2.GIF upsized to 640x480, level adjusted, sharpened, 40%
upsized to 640x480, level adjusted, sharpened, 40%
30%
30%
40%
40%
50%
50%
60%
60%
70%
70%
80%
80%
90%
90%
100%
100%
Level Adjustment settings
Level Adjustment settings
40%
40%
50%
50%
60%
60%
Unsharp Mask settings
Unsharp Mask settings
40%
40%
50%
50%
60%
60%
o6%2f85%2f190885%2f1%2f80301271.PLjEnygb.palegreenspacer5.GIF o6%2f85%2f190885%2f1%2f80301274.ZdMSkYjO.palegreenspacer6.GIF o6%2f85%2f190885%2f1%2f80301251.yryrL31L.palegreenspacer3.GIF o6%2f85%2f190885%2f1%2f80301262.DbA8Pa0Z.palegreenspacer4.GIF