What is NeatVision
Graphics File Formats
first problem which needs to be addressed in the development of any image
processing software is interpretation of image resource files containing
bitmap or raster information. Java provides support for the two most common
file formats found on the Internet, Graphics Interchange Format (GIF) and
Joint Photographic Experts Group File Interchange Format (JPEG). Unfortunately
these file formats are not used for computer vision applications as the
compression techniques which they employ distort image information. The
pixel error introduced by either compression technique is typically 1%,
although this may not be visually apparent but it does result in unacceptable
information loss. In order to preserve image information, support for several
non-corrupting file formats has to be implemented in Java, the three main
formats required are raw image data (BYT), PC Paintbrush (PCX) and Tagged
Image File Format (TIFF).
- (Read-only format), W - (Read and Write format)
(RW) Microsoft Windows Bitmap (BMP), a bitmap image file using Run
length encoding (RLE), supports a maximum pixel depth of 32 bits. A maximum
image size of 32K x 32K pixels, originally created by the Microsoft Corporation
for use with Windows Version 1.0.
(RW) Raw image data, grey-scale only with a maximum pixel depth
of 8 bits the data is stored with the first byte of the file corresponding
to the top left hand corner of the image. No header is contained within
the image and details about the dimensions must be supplied by the user.
This file format preserves image data, no information lost since no compression
(R) Kodak FlashPix.
(R) Graphics Interchange Format (GIF) is a bitmap file which utilises
Lemple-Zev-Welch (LZW) compression, it is limited to a maximum colour palette
of 256 entries and a maximum image size of 64K x 64K pixels.
(RW) Joint Photographic Experts Group (JPEG) File interchange format
is also a bitmap file it utilises JPEG compression, an encoding scheme
based on the discrete cosine transform, It has a maximum colour depth of
16.7 million colours and a maximum image size of 64K x 64K pixels.
(RW) PC Paintbrush (PCX), a bitmap file using either no compression
or RLE, image data is kept intact, A maximum colour depth of 24 bits is
available and a maximum image size of 64K x 64K pixels.
(RW) Portable Network Graphics.
(RW) Portable BitMap. The portable bitmap format is a lowest common
denominator monochrome file format. It was originally designed for mailing
bitmaps between different platforms using typical network mailers. Now
it serves as the common standard for a large family of bitmap conversion
(RW) Portable Greymap Utilities (PGM), a bitmap file uses no compression
hence image data is left intact, it has a maximum grey-scale depth of 256.
(RW) Portable PixelMap.
(RW) Sun Raster Image (RAS), a bitmap file format using either no
compression or Run Length Encoding (RLE) supports a maximum of 16.7 million
colours and has an undefined maximum image size.
(RW) Raw image data Similar Specification to the BYT format described
except colour image data also supported. The image data is stored in RGB
triplets with the triplet representing the upper left hand corner of the
(RW) Tagged Image File Format (TIF) a bitmap file using a wide range
of compression techniques, uncompressed, RLE, LZW, International Telegraph
and Telephone Consultative Committee (CCITT) Group3 & Group4 and JPEG
supports a maximum pixel depth of 24 bits (16.7 million colours)
and a maximum image size 4 Gig pixels.