What's the difference between PAINT and DRAWING art editors - and which makes sharper pictures?

PAINT EDITORS

PAINT ART EDITORS lay down a computer picture as a bitmap, pixel by pixel like a tapestry.

Drawing editors create the image in quite a different way, from a mathematical formula.

PAINT PROGRAMMES, like digital cameras and camera phones, are pixel dependent. Megapixels may not be everything, but as a rule the more megapixels the merrier. You tend to get sharper pictures the more pixels there are, and the closer they are together.

With millions of colours and dots, desktop paint editors can handle great subtlety of shading and are mainly used for photo editing. Programs like Photoshop (or Elements) and Painter allow you to paint with wonderful, lifelike art materials like oil paint, pastel and watercolour.

How large you can show a bitmap depends on the number of dots it contains. If you magnify a tiny image like the smallest favicon, 16 x 16 = 256 pixels, you'll see the individual pixels display as a mosaic of squares. You can see the pixels even in the large (32 x 32) favicon here.

Digital photos, which camera phones almost always save as JPEGS, are bitmaps. A shot from a multi-megapixel digital camera can be magnified many more times than a favicon and not lose its sharpness. A megapixel is a million pixels. But with millions of pixels instead of 256, a digital photo can make a huge file.

Digital cameras in many mobile phones take much smaller pictures. It was not so long ago that no camera phone took photos of more than a third of a megapixel, which naturally can't be shown or printed very large and still look sharp. But picture phones are evolving at breakneck speed. My Nokia N80 is a 3 megapixel phone.

Meanwhile you may be disappointed in the resolution from an older camera phone when you show your photos on your desktop or try to print them. At the start, most mobile phone photos were really only for sending to another handset, for display on a tiny screen. They don't always blow up well - although you can often use that grainy effect to give an evocative image rather like a painting.

If you show your photos on a desktop screen or send them by email, it's a good idea to reduce them to half size. (Keep the original!) Reducing to 50% will sharpen your pictures up, and of course make a smaller file.