While the raw version of the image requires 393,216 x 3 = 1,179648 bytes for storage, the JPEG image compression standard can reduce the number of bytes needed for storage to 81,699. This is about 7% of the amount of space needed to store the original image. The compressed image is an approximation to the original. The compression process identified information that could be discarded in order to reduce storage space. Thus it is impossible to exactly reconstruct the original image from the JPEG image. This compression process is known as lossy compression. If you look carefully at both the original image and the JPEG compressed version of the image, you will see some differences. In some places, the JPEG image looks blocky. This was one of the problems addressed by the JPEG committee when they created the JPEG2000 image compression standard.