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| Home › Support › Breeze Help > "File formats: JPEG-2000" options dialog box
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This dialog allows you to specify parameters of JPEG-2000 file / stream format.
The following options allow you to specify JPEG-2000 file / stream:
"Color space" group box
This group box allows you to specify a color space used as an internal format
in the JPEG-2000 image.
Click a radio button in this group box to select a required color space.
"Bit depth" group box
This group box allows you to specify a bit depth of each color component.
Table below shows how many colors there are in the images with the different
bit detpth:
| Bit depth |
Colors in the grayscale image |
Colors in the color palette image |
Colors in the color RGB image |
| 1 |
2 |
2 |
not applied |
| 2 |
4 |
4 |
not applied |
| 4 |
16 |
16 |
not applied |
| 8 |
256 |
256 |
16777216 |
| 16 |
65536 |
not applied |
281474976710656 |
Click a radio button in this group box to select a required bit depth.
"Compression" group box
Controls in this group box allow you to specify a type of compression used in
the JPEG-2000 image.
- Lossless - no color information is lose during compression
- JP2 - lossy JP2 codec
- JPC - lossy JPC codec
"Quality" slide, edit and spin boxes allow you to specify a level of quality
for JPEG-2000 compression, from 1 to 1000.
The higher a quality of a compressed the lower level of compression (size of
compressed file is bigger). Usually level of quality about 100 - 300 provides
very high guality final images (PSNR more than 40).
At the level of quality less than 500, size of the compressed JPEG-2000 file
can be estimaged as
(Size of uncompressed image) *
Quality / 1000 .
For example, image with a quality about 200 will be about 5 times smaller than
original uncompressed image, and image with the quality about 100 will be about
10 times smaller.
Remarks
JPEG-200 supports lossless and lossy compression algorithms.
If lossless compression is used then color information is not lost in the
JPEG-2000 image during compression itself, and a quality of an image converted
into the JPEG-2000 format is same as it was the original uncompressed image.
There are two major exceptions from this rule. JPEG-2000 image internally may
be presented in the different color spaces and with the different color bit
depth. As a result some color information may be lost if during JPEG-2000
compression:
- Color space of the original image is converted
into another color space with a smaller number of color components.
- Bit depth of the original image is reduced.
For examlpe, color information is lost when original color image is saved as a
gray JPEG-2000 image; or when original image with 8 bit color depth is saved as
a 4 bit JPEG-2000 image.
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