JPG file format

.jpg

JPG – is a popular graphic format characterized by a high image compression rate, which leads to a decrease in image quality. It uses the technology of encoding smooth color renditions, providing the ability to frequently reduce the amount of data during the image's recording. Because of the small size, it is requested by the owners of websites, allowing you to save the traffic effectively. It is also frequently used in memory cards of digital video cameras. The JPG algorithm is optimally suitable for compressing photographs and pictures in which realistic scenes with little contrast of colors are present. It is not recommended to use this format for compression of drawings and various kinds of graphics. A strong contrast between several near located pixels provokes the appearance of visible artifacts.

The procedure for compressing the digital images in JPG format is carried out in several stages. First, the photo is transformed into a color space YCbCr, and then it is divided into squares to determine the upper range of the color spectrum. Finally, the colors and brightness are coded. JPEG uses a "lossy" compression system and discrete cosine transform technology. The format acts simultaneously as the standard of ISO and the International Telecommunication Union. The file compression ratio is in the range from 10:1 to 100:1. In this case, the reduction in image quality can vary from insignificant to substantial.