Images — Photographic

JPEG Images

Photographic images on the internet are usually in JPEG format. JPEG is the acronym for the Joint Pictures Expert Group, a working party under the auspices of the International Standards Organisation (ISO). JPEG is know as a 'lossy' format, meaning that the picture loses some information between when being encoded or compressed. The human eye is generally unable to discern the loss of this information and so 'sees' the image as being same as the original image.

Why JPEG for photographs?

The JPEG format can support millions of colours. Thus it is not subject to the limitations of the GIF format which can only support a maximum of 256 colours. To illustrate the difference this makes take a look at this picture of a sunset.

firstly in JPEG format

and then in GIF format.

Notice the 'banding of the colours in the sky. Also the GIF image is some 2½ times the size of the JPEG which was saved at 'best' quality. Had the jpeg been saved at a lower quality the file size benefit would have been even greater.

Photo Manipulation

It is possible to digitally enhance and manipulate any image used on the web. Indeed most images on the Web have been manipulated to a greater or lesser extent, whether this is for the purposes of brightening them up or something much more radical.

Photo Montage

This is the process of taking images, or parts of an image, from two or more sources and creating an entirely new picture. For instance this man may have never visited New York's Times Square in his life:

and this girl could have never found herself in this position:

 

Click here to see how these montages were created.

Creative Manipulation

Montages are not the only 'artwork' it is possible to create. This pen and ink style drawing:

was created by manipulating this photograph: