lossy data compression
Lossy compression is based on the perceptual ability of the viewer or listener.
Thus, due to human brain activity and the resolution capability of colors, shapes, and sounds in graphics, audios, or videos, information can be changed or removed without significantly changing the perception and worsening the subjective impression. Therefore, lossy compression has much higher compression rates than lossless compression.
When a lossy compression file is decompressed, the exact original image can no longer be reconstructed because the data reduction is not based on mathematical procedures, but on changes of state that are reflected in impressions and experiences and that are implemented in algorithms. The deviations of the compressed image from the original image depend on the degree of compression and the compression method chosen. The best-known lossy compression method for images, photos and graphics is JPEG.