Artifacts on the images

The graphics artifacts are unwanted features of the image appearing in certain conditions.

The compression artifacts

While lossy compression might be noticeable distortion of image, sound, video, etc., defined by the algorithm.

For example, the artifacts of JPEG compression and MPEG in case of a large aspect ratio are rectangular fields of the same color, which can take quite large monochromatic areas of the image or other visual defects (the transformation of the small moving parts of the image in squares, stripes, and uniform plots in a heterogeneous mass with prominent fragments, etc.)

The compression algorithms are lossless:

• RLE — is used in formats PCX — the main method in the following formats: BMP, TGA, TIFF as one of the available.
• LZW — used in GIF format
• Deflate — used in PNG format

Algorithms of compression with losses:

• JPEG
• On the mobile platform - convert the image to palette format.
• JPEG 2000
• The algorithm of fractal compression
• DXTC (texture compression is implemented in the graphics API of DirectX).
• Differential compression (compression is based on the formation of the boundary conditions and the choice of differential equations, solution of selected differential equations, with the computed compressive boundary conditions, allows to restore the original image).

When performing block coding for quantization, as in JPEG-compressed images, there may be several types of artifacts:

• block distortion
• wave
• ring
• noise around edges, blurring

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