signed images

[Guest_imported]

hello

i was hoping someone may be able to explain the difference between a signed image and an unsigned image. and what type of image is a tiff image. I am writing a plugin in java that manipulates image pixels but when i multiple the pixel value it does not like it and i think it is because it is an unsigned image?

any help would be much appreciated
thank you, waiting in anticipation

ROB - robsroom@hotmail.com

 

[carpeliam]

TIFF is tagged image file format.. basically, from what I know, it's an &quot;exact copy&quot; of the input- nothing is lost in copying, moving, or anything. It's a &quot;tag&quot;, an exact replica, of the original. That's an awful explanation, I'm sure. And signed vs. unsigned: my first guess is that it has something to do with the bits.. for example, an unsigned number is one that can only be positive because the bit pattern of 0's and 1's does not specify it's &quot;sign&quot;. A signed number is one that indicates it's positive or negative value. I'm aware of signed audio files as well... see if you can translate this into image files:<br><br>&quot;Signed vs. Unsigned&quot; (from the Help Menu for Goldwave Audio Editing program):<br>Specifies that 8 bit, 12 bit, or 16 bit samples are signed.&nbsp;&nbsp;Amiga and Apple systems use signed 8 bit (-128 to 127) or signed 16 bit (-32768 to 32767).&nbsp;&nbsp;Wave and Sound Blaster files for PCs are usually unsigned 8 bit (0 to 255) or signed 16 bit (-32768 to 32767).&nbsp;&nbsp;Generally, all 12 bit and 16 bit samples are signed.<br><br><br>I presume that something similar goes for images, although I don't believe that helps very much... more like half of a technical explanation. Sorry... <br><br>Liam Morley<br><A HREF="mailto:"></A><br><A HREF="

http://www.wpi.edu/~lmorley/"

TARGET="_new">

http://www.wpi.edu/~lmorley/</A><br>&quot;light

the deep, and bring silence to the world.<br>
light the world, and bring depth to the silence.&quot;

 

[Chrissirhc]

Okay I've been looking into images a bit. But no one has replied to my message about images and arrays. If you get an image and create an Image you can make BufferedImage get the raster using some method and then get the array out of that manipulate the array and then get writeraster out of the buffered image and write your array onto it. I'm not too sure about JAI yet because the images in that are different from Java2d if you understand them then can you write back to me. Hope I helped a bit