Compress JPG

All files are stored in computer memory as a set of binary numbers. As a rule, they are grouped in sets of eight bits, that is, in bytes. When unpacking a JPEG, the operating system must decode this information, which will restore the original image in the format of a list of colors to be displayed. If you need to compress the image more, you can't do without quality loss. What are the principles? First, any image contains a certain amount of redundancy, the removal of which will not lead to a noticeable change in the quality of the picture. Second, the human eye is more susceptible to changes in brightness than color. Therefore, for different image channels, different compression rates are applied - information is lost, but visually it is not noticeable. In addition, the eye's sensitivity to small image elements is low, which allows them to be removed without compromising quality.

The JPEG compression process consists of several steps. The first step is to convert the image from RGB color space to YUV space, based on the characteristics of luminance and chromaticity. All further work is done with this color space, which, due to some of its characteristics, allows us to obtain such large compression ratios. The format is a lossy compression format, so it is incorrect to assume that JPEG stores data as 8 bits per channel (24 bits per pixel). On the other hand, since JPEG compressed data and decompressed data are usually represented in 8 bits per channel format, this terminology is sometimes used. Compression of grayscale images is also supported. If not for the jeep, the Internet would be completely different now. I think, outwardly, it would resemble the sites of the 90s. And we would not be able to easily instagram everything and watch pictures of cats on the phone) Besides, this algorithm is the basis of video compression!