Pros and Cons of Bitmap File Formats
Bitmap files are especially suited for the storage of real-world images;
complex images can be rasterized in conjunction with video, scanning, and
photographic equipment and stored in a bitmap format.
Advantages of bitmap files include the following:
Bitmap files may be easily created from existing pixel data stored in an
array in memory.
- Retrieving pixel data stored in a bitmap file may often be accomplished by
using a set of coordinates that allows the data to be conceptualized as a
- Pixel values may be modified individually or as large groups by
altering a palette if present.
- Bitmap files may translate well to dot-format output devices such as
CRTs and printers.
Bitmap files, however, do have drawbacks:
- They can be very large, particularly if the image contains a large number of
colors. Data compression can shrink the size of pixel data, but the data must
be expanded before it can be used, and this can slow down the reading and
rendering process considerably. Also, the more complex a bitmap image (large
number of colors and minute detail), the less efficient the compression process
They typically do not scale very well. Shrinking an image by
(throwing away pixels) can change the image in an unacceptable manner, as can
expanding the image through pixel replication. Because of this, bitmap files
must usually be printed at the resolution in which they were originally
This page is taken from the Encyclopedia
of Graphics File Formats and is licensed by O'Reilly
under the Creative Common/Attribution license.