Full Colour Photographs, File Formats and Compression

photograph of flower, original jpeg, cropped and re-saved as 100% quality
Above: photograph of flower, original jpeg, cropped and re-saved as 100% quality. Size 219k bytes 		photograph of flower saved as 10% quality jpeg
Above: photograph of flower saved as 10% quality jpeg. Size 10k bytes. You can see some of the "compression artefacts" in the blockiness of the flower petals.
photograph of flower saved as gif
Left: photograph of flower saved as gif. Size 151k bytes. You can see some of the banding caused by the limit of 256 colours. (see the colour depth example for a clearer illustration of this problem)