Discrete Cosine Transform DCT Methods on Compression RGB and Grayscale image

This paper presents a study of image compression methods algorithm for techniques on lossy image compression. One of the major difficulties encountered in lossy image compression is how to protect image quality in a way that the compressed image remains identical to the original, different from the types of methods that exist in the lossless image that can maintain the quality of the image's authentiqly. Digital image compression is a data compression application that aims to reduce the redundancy of data so that theimage can be stored and transmitted efficiently. For compression image, the methods that are often always used is lossy compression and for this research we try to use Discrete Cosine Transform (DCT). Discrete Cosine Transform (DCT) is a technique for graphics signals into basic frequency components. Base on the result this research will be show comparison size of compressing image between grayscale image and color (RGB) image measurement of experimental results using PSNR and MSE. The better one compression scheme having a lower MSE and a high PSNR is DCT method for RGB or color image that is: peppers.bmp (MSE:0.02 and PSNR: 65.6070).