  In this work, we present a comparison between different techniques of image
compression. First, the image is divided in blocks which are organized
according to a certain scan. Later, several compression techniques are applied,
combined or alone. Such techniques are: wavelets (Haar's basis), Karhunen-Loeve
Transform, etc. Simulations show that the combined versions are the best, with
minor Mean Squared Error (MSE), and higher Peak Signal to Noise Ratio (PSNR)
and better image quality, even in the presence of noise.
