* Only pictures of type GIF and JPG can be viewed directly by browsers. Other types must be first downloaded and then loaded into a graphics program.
Any graphics program worthy of the name will allow you to save a picture in either format.
I use Paint Shop Pro which is quite servicable and not expensive.
Programs like Photoshop and Corel Draw are very complex and expensive and will probably confuse you unless you are a digital graphic artist.
The free one(s) that come with Windows are quite feeble, but usable if you have nothing else.

* For photographs, the JPG is by far the best to use.
* Use GIFs only for diagrams and cartoonlike images.
Please note that renaming a file to have the extension .GIF or .JPG does NOT change the format of the file to that type, and may really confuse a browser and could even make it crash.

* REDUCING THE SIZE OF A JPG
JPGs have compression built into their format. You should be able to tell your graphics program how much to compress it.
You might try saving it with increasing amounts of compression and then reloading it to see if it has lost very much quality. Depending on your graphics program, you probably need to reload it to see the results of the compression.
Be sure to not overwrite your original with a compressed version, as you can't UNcompress it. Start with the middle amount of compression. JPGs can be easily reduced by more than half their filesizes without noticeable deterioration.

* REDUCING THE SIZE OF A GIF (This is for more advanced users.)
GIFs are compressed also, but in a totally different manner, similar to ZIP files. Dithering of images prevents the GIF compression method from working very well. The use of the browser-safe palette is highly recommended. Space can be saved by reducing the palette to either 16 or 2 colors only.
If your image is a line-drawing, reduction to 2 colors is highly recommended. GIFs of photographs tend to by VERY large. Avoid using them.
To convert a gif to a jpg, and undo much of the dithering: increase its color-depth to 24-bit color. If the image is large enough, you can apply a "blur" or "soften" to it without losing any noticable quality, but saving a lot of disk space and download time. Then save it with compression as described for JPGs.

* REDUCING THE SIZE OF ALL PICTURES
Method 1: CROP the image, eliminate any superfluous border material which does not add anything useful. Just leave more or less the important (approximately) CENTER of the image.

Method 2: REDUCE THE DIMENSIONS of the image (expressed in height and width in pixels). Graphics programs call this "resizing" and "resampling". Resampling is the best method for JPGs.
500 x 350 pixels is a good maximum size for viewing with browsers.
INCREASING the size of a picture will NOT add any detail and just wastes space.

Graphics programs allow you to do these operations easily.

It is best do any compression steps in the following order:
    Palette reduction / softening, cropping, resizing/resampling, saving (JPGs) with compression.

You will get the best results when resizing/resampling from your original image to the final size you want. Reducing the size in several smaller steps will cause the image to deteriorate more.

It is ALWAYS a good idea to view your picture with a BROWSER before uploading it.

Jules Siegel

Click your BACK BUTTON to continue.