fre, 11 07 2008 kl. 01:10 -0400, skrev de Almeida, Valmor F.:
Yep. It does work. However it is a little tricky to compare the max(Y(:)) and min(Y(:))
values octave has in memory with the output of imagemagick's "identify" tool.
Just for the record. In the following output from identify
Format: PNG (Portable Network Graphics)
Class: DirectClass
Geometry: 275x220+0+0
Type: Grayscale
Endianess: Undefined
Colorspace: Gray
Depth: 16-bit
Channel depth:
Gray: 12-bit
Channel statistics:
Gray:
Min: 774 (0.188968)
Max: 1558 (0.380377)
Mean: 1213.52 (0.296275)
Standard deviation: 95.3054 (0.0232683)
Octave's values for min and max are: 12384 and 24928. These are obtained from multiplying
the corresponding numbers in parentheses from the "identify" output by 65536.
Hmmm, that's a bit odd isn't it? It seems that
0.188968 * (2^12 - 1) = 774
and
0.188968 * (2^16 - 1) = 12384
So, this is somehow related to the fact that the image is 12 bit but is
read as 16 bit. Should the minimum value be 774 (as ImageMagick reports)
or should it be 12384 (as Octave reports) ? I mean, who's right?