Results of JPEG Compression.

This page compares an original color image, and a black and white image, with many different JPEG-compressed versions. The results use different quality factors and smoothing factors; zero smoothing and 100 % quality yield the least distortion. These results used a zero smoothing factor. Table 1 compares the quality factor with the compression ratio (including overhead) for the color and b/w images.

COLOR IMAGES

Here is the original color image. The results of JPEG color image compression lie behind the respective links. The difference picture link sits to the right of the corresponding JPEG image. The visible difference between quality factors above 35 is relatively small; between quality factors below 10 there is a big difference. The quality factors were chosen accordingly.

  1. Quality Factor of 75 , the Difference Picture (75).
  2. Quality Factor: 20; the Difference Picture (20).
  3. Quality Factor: 5; the Difference Picture (5).
  4. Quality Factor: 3; the Difference Picture (3).

BLACK and WHITE IMAGES

The black and white version of the original image.

  1. Quality Factor of 75, the Difference Picture (75).
  2. Quality Factor: 20; the Difference Picture (20).
  3. Quality Factor: 5; the Difference Picture (5).
  4. Quality Factor: 3; the Difference Picture (3).

Comments on Results

The color images achieve better compression ratios, but still produce bigger compressed files. Although image appearance is subjective, the black and white image seems to withstand higher compression, and still look fine; a quality factor of three show this fairly well.

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