When you create a good 3D picture it seems all is finished and OK. But there could be one problem - saving your image to a wrong image file format can destroy your great work.
When you save a image to a file, you can often choose from variety of formats. The most often used are GIF, JPG (JPEG), TIF (TIFF), BMP and PNG. Everyone of them has it's adwantages and it's drawbacks.
Advantages and disadvantages
Pictures saved as GIF or JPG could create quite a small file - much smaller than for example BMP. It's the reason why they are often used as web graphics - they can be downloaded very quickly.
Both these formats compress the image data; JPG uses losing compression - it means that some data are lost forever (for example small details in the picture). This is very unpleasant in 3D pictures/anaglyphs - their 3D effect needs sharp details. In graphical editors can be often set the value, which determines the quality of the compression (but: the more quality of the picture, the bigger image file).
GIF uses lostfree compression (no data are lost), but there is another problem: Standard GIF can save only 256 colors. It's not too much. In some graphical programs can user choose how to convert the full-color image to the 256color one. (Until 2003 (in USA, worldwide until 7/2004) there were licence problems with the GIF.)
The TIF format offers lostfree compression and a lot of collors - but needs bigger files. Sometimes there are problems with compatibility of this format - there are a lot of TIF standards and not every software understands all of them. Sometimes you get only a lot of random dots instead of your picture.
BMP don't uses compression, but offers good compatibility and full image quality. In our opinion it is the best format for saving your own 3D images. When you save 3D image to BMP, you can experiment later with other formats (for example convert it to GIF and JPG to show it on web) - but on your disk can be still the full quality image for later uses.
PNG is a newer standard - and not so often used as GIF or JPG. It offers a good compression and you can choose number of used colors.
We've placed 3D photo in 4 different formats to this page. Look at the very much compressed JPG (the picture isn't very good, as you can see), sharp GIF - but with worse colors, PNG and BMP - with good quality but bigger files (but if PNG uses 256 colors then it's size is similar to the size of GIF). If you want to show a picture on web we recommend to use GIF (or PNG) - in most cases the lost of colors isn't a big problem.