Image Types Images used in the making of web pages are of three file types: BMP images are high quality, and can be edited by most image programs. They retain their quality level when saved. However, these are large in size, and also can not be used on a web page. Instead, other imagefile types are converted to 'bitmaps' for editing; then the changed images are turned back into .jpg or .gif format. JPG images can be used on a webpage, and are best for photorealistic images (eg: photographs). They compress to a very small package (in terms of information), making them load quickly when the page they are on is accessed; they are also easily edited on most software. Compressing these files causes them to deteriorate in quality, however, so if a particular image needs to be worked on many times, it is best to convert it to a bitmap before editing it. GIF images can also be used on a webpage. This format is best for solid-colour 'drawn' images, or cartoons. This is also the format used by animations. You can use Irfanviewer to convert an image from one format to another. The usual procedures are as follows: - Save your original creation or photo as a BMP image to use as backup in case you mess up. - Edit your image with your image editing program, and resave it as a BMP. - Use Irfanviewer to convert it to 256 colours, and save it as a GIF (if it's drawn) or a JPG (if it's a photo). This usually results in a small file size. Sometimes, though, it's worth trying both, as one or the other file type may give you better results. Sometimes with a title that has text and graphic elements, you may find that the 'smearing' that occurs for some colours in JPG compression is unacceptable, and you may choose to accept the bigger file size of a GIF with it's sharper result. Experiment! (Just try to keep all graphics under 20K in size if possible.) All of our own photographic images are converted to JPG images that are quite small ... often only 300 by 300 pixels, and compressed at only 90%. (The higher this percent, the less compression). Compressing the pictures by only 10% makes for very little distortion, but would result in a fairly large in memory size; that's why we reduce their physical size to (usually) no more than 300 pixels wide. Most of our images end up being less than 30K, with many at 20K or even less. Watch out for image deterioration of your JPG images! Repeatedly opening a JPG image to work on, and resaving, will cause further compression, and eventually the image will begin to look ragged. That's why you should work only with BMP images, and convert to JPG when done. BACK