1. Image from SciFi channel. The image was gamma-corrected in software. Notice the color noise, which somewhat resembles quantization artifacts. This noise, which is especially noticeable in dark regions, was accentuated by the image processing step.

2. Unretouched image from Russkia Mir, showing a Russian-language news program. In this image, you can see faint MPEG artifacts, for example around the blue MIR logo box. These look like propagation delay artifacts that you would get with an antenna, except that they occur in two dimensions.

3. Unretouched image from QVC, showing the marked deterioration in image quality and MPEG artifacts that occur when signal strength is weaker. On a regular TV, the same signal only shows faint banded noise.