Game Development Reference
In-Depth Information
The graphic file formats
There are literally hundreds of image file types. The PNG, JPEG, and GIF file formats
are most often used to display the most common image types. They are listed as fol-
lows, divided by family.
Raster graphics
The following file formats are from the family of raster graphics:
•
Joint Photographic Experts Group
(
JPEG
): This is a compression method;
JPEG-compressed images are usually stored in the
JPEG File Interchange
Format
(
JFIF
) file format. JPEG applies lossy compression to images, which
can result in a significant reduction of the file size. The amount of compression
can be specified, and the amount of compression affects the visual quality of
the result. When not too great, the compression does not noticeably detract
from the image's quality, but JPEG files suffer generational degradation when
repeatedly edited and saved.
•
Tagged Image File Format
(
TIFF
): This is a flexible format that normally
saves eight bits or 16 bits per color (red, green, and blue) for 24-bit and
48-bit totals, respectively, usually using either the TIFF or TIF filename ex-
tension. TIFF's flexibility can be both an advantage and disadvantage, since
a reader reads for every type of TIFF file that does not exist. TIFFs can be
lossy and lossless; some offer relatively good lossless compression for bi-
level (black and white) images. TIFF image format is not widely supported by
web browsers. TIFF remains widely accepted as a photograph file standard in
the printing business. TIFF can handle device-specific color spaces, such as
the CMYK color model defined by a particular set of printing press inks.
•
RAW:
This refers to a family of raw image formats that are available as options
on some digital cameras. These formats usually use a lossless or nearly
lossless compression, and produce file sizes much smaller than the TIFF
formats of full-size processed images from the same cameras. Although there
is a standard raw image format, (ISO 12234-2, TIFF/EP), the raw formats
used by most cameras are not standardized or documented, and differ among
camera manufacturers.
•
Graphics Interchange Format
(
GIF
): This is limited to an 8-bit palette, or 256
colors. This makes the GIF format suitable for storing the graphics with relat-
ively few colors, such as simple diagrams, shapes, logos, and cartoon style
