Thus the image reduces in size since the ‘y’ component is not touched, there is no noticeable loss of image quality. Down sampling is done either at a ratio 2:1 horizontally and 1:1 vertically (2h 1 V). Transformation: Color images are transformed from RGB into a luminance/chrominance image (Eye is sensitive to luminance, not chrominance, so that chrominance part can lose much data and thus can be highly compressed.ĭown Sampling: The down sampling is done for colored component and not for luminance component. Before going into the JPEG file format specifications, the overall process of steps involved in JPEG creation need to be mentioned. Even the web browsers support visualization of JPEG images. Almost all Operating systems now have viewers that support visualization of JPEG images, which are often stored with JPG extension as well.
The format has been the choice of storing and transmitting photographic images on the web. JPEG image file format was standardized by the Joint Photographic Experts Group and, hence, the name JPEG. The higher the compression value, the higher the degradation in image quality. Image quality is negligibly affected if 10:1 compression is applied to the image. Users can adjust the compression level to achieve the desired quality level while at the same time reduce the storage size. The output image, as result of compression, is a trade-off between storage size and image quality. A JPEG is a type of image format that is saved using the method of lossy compression.