How can you make small Images?
Some images need to be made smaller. Some are already small in file size. The charts on pages 32 and 33 highlight some of the optimization options available to you with each different file format, JPEG and GIF.
JPEG - Photographs, add blur, compress more, decrease color saturation, decrease contrast.
GIF - Lots of solid color, reduce the number of colors, reduce the amount of dithering, add lossy compression.
PNG format is a newer format that is somewhat more advanced than both GIF and JPEG. PNG stands for Portable Network Graphics but is not supported by the major browsers yet.
Another factor of file size is bit depth. Bit depth has to do with the number of colors in a graphics file. GIF is an 8 bit file format where JPEG is a 24 bit file format. Examine the chart on page 35 then begin your lesson on page 36. Remember to change the file attributes from read-only so you can edit and save the files.