  Due to the increasing requirements for transmission of images in computer,
mobile environments, the research in the field of image compression has
increased significantly. Image compression plays a crucial role in digital
image processing, it is also very important for efficient transmission and
storage of images. When we compute the number of bits per image resulting from
typical sampling rates and quantization methods, we find that Image compression
is needed. Therefore development of efficient techniques for image compression
has become necessary .This paper is a survey for lossy image compression using
Discrete Cosine Transform, it covers JPEG compression algorithm which is used
for full-colour still image applications and describes all the components of
it.
