GIF GRAPHICS AND JPEG PHOTOS
What's the difference?

If you think a JPEG is something for hanging out the washing, here are a few useful facts about cell phone graphics, photos and web images

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Thought for the day.
Overweight images make overweight phone bills!

I made this banner in my early days on the web. It's a JPEG (or jpg).

A JPEG is one of the two kinds of picture files most widely used on the net and in digital cameras - including camera phones. The other kind are GIFs.

JPEGs and GIFs are readable by Macs, PCs and even ancient browsers held together with bits of string. They're about as universal as you can get. Both JPEGs and GIFs are used by most mobile phones that have a colour display, and by Palms and Pocket PCs.

There's another advantage to being as common as mud. Jpeg and gif images are unlikely to become unreadable by tomorrow's technology. An important point to remember if you're saving digital pictures for posterity.

If treated properly, gifs and jpegs can also make very small files.

JPEG today is the most common format in which digital cameras and mobile camera phones save photos. GIFs are often used as pda and camera phone screensavers. Both file types can be sent as mobile multimedia messages.

Gifs have the advantage that they can include animation. Gifs also allow transparency, so cutout shapes can stand out against the background colour of a page. Jpegs permit greater subtlety of colour and shading.

Computers have gathered speed since the heyday of banners, but in any web design it's still vital to make graphic files as small as possible so they load fast. Some surfers pay for online time by the minute. Even if you only load your photos on a web page for friends to see, it's important the pictures show quickly.

On mobile phones and the mobile internet, it's more important still. Phones have small memories, low bandwidth and high prices! As you may have discovered, overweight images make overweight phone bills. Whether you pay by the megabyte or the minute, fat pictures cost more and amble along very slowly. That's if you can send them by MMS at all.

JPEG AND GIF PROS AND CONS

JPEG images give wonderful effects, but they're 'lossy'. They're widely used because they make much smaller files than most photo formats. They do this by removing picture elements the eye can't detect. Beware! Edit a photo and save it once and your picture looks none the worse. Titivate and save it several times over and you will see what you've lost.

During another comparison test - of art materials - I painted an orange with oils and scanned it into my computer. I converted the picture to a JPEG (shown first) and a GIF.

You can see that the JPEG conveys the nuances of shading. The GIF curdles and posterises the colour. I had to reduce the .gif to only eight colours in order to cut down the file size. Even then it's 6,136 bytes - almost half as much again as the JPEG at only 4,261 bytes.

GIF comes into its own for lettering and animation

Unlike the example above, many .gif pictures can be reduced to extremely small files. You have to experiment to get the best results. Automated processes can help you so far, and no further. Photoshop allows you to cut down the colours of a GIF to an absolute minimum - with a good deal of control. Give your rainbow a trim with Photoshop or Elements and you can make really small files.

PURPLE MORAL

They say GIFs aren't 'lossy'. That is, they don't lose information every time you save them as JPEGs do. Don't forget, though, that if you remove colours from a .GIF, then save it, the colours are lost.

ALWAYS KEEP YOUR ORIGINAL before you make changes. Make a copy and edit that - and save your edited versions with different names.

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GIF graphics and JPEG photos. What's the difference?

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