What is JPEG image compression?
JPEG stands for Joint Photographic Experts Group, an association that has defined a standard image compression technique and file format that is supported by many different image editing programs. JPEG allows for adjustable levels of compression — image quality goes down as you increase compression. Amazingly, the JPEG compression technique can reduce the size of an image by a factor or 5 to 10 with little or no visible image quality degradation. JPEG compression works by breaking up your image into 8×8 pixel squares, analyzing each one using a mathematical technique called a Discrete Cosine Transform, and discarding frequency components that fall below a certain threshold based on the compression level you select. The remaining data are compressed using Huffman coding and stored in the output file. JPEG files are decompressed using a similar technique. By using JPEG image compression, Picture Window is able to reduce your images to a size that fits easily on floppy disks. This provid
Related Questions
- JPEG is a lossy compression method. This means that some sacrifices in image quality are made to reduce the size of the image. I give a somewhat informal description of the process in my answer above on: In what format should I save my images once Ive transferred them to my computer?
- How does image compression obtained with foveated imaging compare to more conventional forms of compression such as JPEG or MPEG?
- What is Lossless Compression?
