Thanks for the fast response.
Just to be 100% clear there is no way to specify the minimum or
maximum colormap size of an palette based png.
I know I can use Optipng or pngnq, but I would like to avoid using a
second binary.
Thanks again,
-Mikel
Search Tags:
8-bit 4-bit 2-bit 1-bit index indexed
On Dec 11, 2007, at 2:31 AM, Anthony Thyssen wrote:
Mikel Waxler on wrote...
| When I use both -depth and -color in one command the -depth gets
| ignored and I end up with a 4-bit (or less) colormap on some images.
| This would be fine except some of the devices I need to read this
| image fail to decode anything less than 8-bit images.
|
| I am getting images from a script that cuts up large images into
| sections. Some of the sections contains a very small number of
| colors, perhaps 1. The test image I am using can be found here:
| http://waxor.com/test.png.
|
| What I need is to convert test.png into a png8 with an 8-bit
| colormap. I can do this by just specifying -depth. I need to specify
| the number of colors, even if it it larger then the number in this
| image since some of my images contain more then 256 colors. This is
| because I need to limit the full size image to say, 70 colors. I
| would like to do this without using 2 convert calls.
|
| //Here are some examples:
| // This works fine
| antenna:~ mikel$ convert test.png -depth 8 png8:png8.png; file
png8.png
| png8.png: PNG image data, 213 x 163, 8-bit colormap, non-interlaced
|
| //this does not
| antenna:~ mikel$ convert test.png -depth 8 -colors 70 png8:png8.png;
| file png8.png
| png8.png: PNG image data, 213 x 163, 1-bit colormap, non-interlaced
|
| // Attempt with 2 calls
| antenna:~ mikel$ convert test.png -depth 8 -colors 70
png8:png8.png;
| convert png8.png -depth 8 png8-8.png; file png8-8.png
| png8-8.png: PNG image data, 213 x 163, 1-bit colormap, non-
interlaced
|
| // 2 calls, reverse order, also fails.
| antenna:~ mikel$ convert test.png -colors 70 png:png.png; convert
| png.png -depth 8 png8:png8.png; file png8.png
| png8.png: PNG image data, 213 x 163, 1-bit colormap, non-interlaced
|
| Am I misunderstanding what -depth should do or should I file a
bug on
| he bug list?
|
Depth is output color depth, it has nothing to do with color index
table
lengths.
If you want exact PNG file control I suggest you use the specific PNG
optimizar programs.. OptiPNG and PNGng
Anthony Thyssen ( System Programmer ) <[EMAIL PROTECTED]>
----------------------------------------------------------------------
-------
The most menacing dwarf battle cry...
Today Is A Good Day For Someone Else To Die!
-- Terry Pratchett - ``Carpe
Jugulum''
----------------------------------------------------------------------
-------
Anthony's Home is his Castle http://www.cit.gu.edu.au/
~anthony/
_______________________________________________
Magick-users mailing list
[email protected]
http://studio.imagemagick.org/mailman/listinfo/magick-users
_______________________________________________
Magick-users mailing list
[email protected]
http://studio.imagemagick.org/mailman/listinfo/magick-users
