Common image compression techniques include RLE, LZW, and CLUT. The most common image file formats, which often use these compression techniques, are GIF, TIFF, JPEG, and PNG. BMP files are generally uncompressed. RLE stores repeated pixels by only recording the color once along with the number of repeats, reducing file size. LZW compresses by storing repeated bit sequences in a table rather than writing them out each time. CLUT reduces colors to a limited palette, cutting the storage needed per pixel.