Graphics format

There exist many different formats you can use to save your pictures - but which are the best? That depends on their use. Here are some common formats:

• PSD: This format preserves the information in all layers. If you're going to continue working with a picture, this is a sensible format to use. You can get large files from it, though.
• TIFF: If you want the best possible quality from your images, this is a common choice.
• BMP: A common format used by Windows. As TIFF, this will preserve the quality.
• JPEG: This format is compressing the images, so that information (details and colour nuances) are lost. You can choose how much you want to compress the image. The format is common in use on the net, as the file sizes are small.
• PNG: A format that can replace both JPEG and GIF on the net. It compress in a different way than JPEG, and has advanced possibilities, such as alphachannel (partly transparent colours) but Internet Explorer doesn't support these. In 8 bit (256 colours) it compress better than GIF.
• GIF: 8 bit format, i.e. maximum 256 colours. A popular format on the net. It has possibilities for one transparent colour and animation.

If you're going to save pictures you want to use on the net, use Save for Web in Photoshop. it gives you an interactive way to compare file size vs. quality, plus it doesn't save unneccessary extra information this way.

1. When I save my pictures, the quality degenerates each time.

This happens when you save your pictures as JPEG (or other formats which loses quality during compresion.) Each time you save a picture in the JPEG format, it is compressed, and you lose more and more details and colour information.

2. My digital camera saves the pictures as JPEG. How should I treat the files when I'm editing them?

Save your files as PSD or TIFF, depending on wether you want to continue editing or they're finished. Save only as JPEG when they're finished and shall be published (in addition to a TIFF file with full quality - in case you'd like to edit further or use it on a later stage.

Back to menu