Legacy ImageMagick Discussions Archive

Hi, when I open with an ImageMagic dll a PNG black-and-white image, I get an image where the white color is replaced with red, i.e. a black-and-red image instead of B&W. Are there additional parameters to set during opening B&W PNG images?

Post a link to an example image so we can review your image and try ourselves.

fmw42,

http://img535.imageshack.us/img535/1351/58632841.png

Your image is grayscale and not b/w (binary). It has an alpha channel that is totally opaque.

identify -verbose 58632841.png

Image: 58632841.png
Format: PNG (Portable Network Graphics)
Class: DirectClass
Geometry: 240x180+0+0
Resolution: 37.8x37.8
Print size: 6.34921x4.7619
Units: PixelsPerCentimeter
Type: GrayscaleMatte
Base type: GrayscaleMatte
Endianess: Undefined
Colorspace: RGB
Depth: 8-bit
Channel depth:
gray: 8-bit
alpha: 1-bit
Channel statistics:
Gray:
min: 0 (0)
max: 255 (1)
mean: 181.455 (0.711588)
standard deviation: 67.0927 (0.263109)
kurtosis: -1.1325
skewness: -0.277844
Alpha:
min: 255 (1)
max: 255 (1)
mean: 255 (1)
standard deviation: -0 (-0)
kurtosis: 0
skewness: 0

Histogram:
1: ( 0, 0, 0,255) #000000 black
4: ( 1, 1, 1,255) #010101 rgba(1,1,1,1)
2: ( 2, 2, 2,255) #020202 rgba(2,2,2,1)
10: ( 3, 3, 3,255) #030303 grey1
3: ( 4, 4, 4,255) #040404 rgba(4,4,4,1)
6: ( 5, 5, 5,255) #050505 grey2
9: ( 6, 6, 6,255) #060606 rgba(6,6,6,1)
9: ( 7, 7, 7,255) #070707 rgba(7,7,7,1)
7: ( 8, 8, 8,255) #080808 grey3
6: ( 9, 9, 9,255) #090909 rgba(9,9,9,1)
10: ( 10, 10, 10,255) #0A0A0A grey4
13: ( 11, 11, 11,255) #0B0B0B rgba(11,11,11,1)
9: ( 12, 12, 12,255) #0C0C0C rgba(12,12,12,1)
16: ( 13, 13, 13,255) #0D0D0D grey5
12: ( 14, 14, 14,255) #0E0E0E rgba(14,14,14,1)
25: ( 15, 15, 15,255) #0F0F0F grey6
17: ( 16, 16, 16,255) #101010 rgba(16,16,16,1)
13: ( 17, 17, 17,255) #111111 rgba(17,17,17,1)
...
Rendering intent: Saturation
Gamma: 0.45455
Chromaticity:
red primary: (0.64,0.33)
green primary: (0.3,0.6)
blue primary: (0.15,0.06)
white point: (0.3127,0.329)
Interlace: None
Background color: white
Border color: rgba(223,223,223,1)
Matte color: grey74
Transparent color: none
Compose: Over
Page geometry: 240x180+0+0
Dispose: Undefined
Iterations: 0
Compression: Zip
Orientation: Undefined
Properties:
date:create: 2010-07-28T11:18:35-07:00
date:modify: 2010-07-28T10:35:53-07:00
signature: b42f42f52321b8fcec035d3394d04a78f6ca1e2630e10b283d7afdd6596303b8
Software: Microsoft Office
Artifacts:
verbose: true
Tainted: False
Filesize: 35.1KB
Number pixels: 43.2K
Pixels per second: 240K
User time: 0.000u
Elapsed time: 0:01.179
Version: ImageMagick 6.6.3-1 2010-07-27 Q16 http://www.imagemagick.org

When I display it in various tools, it looks normal grayscale and no red! I see nothing to indicate that it should show with red anywhere!

What version of IM are you using? I am using IM 6.6.3.1 Q16 Mac OSX Tiger.

Perhaps you need to upgrade your IM?

Have you tried to open it in any other image viewer?

Perhaps you're using your PNG pictures in a viewer that doesn't understand grayscale PNGs (I mean when the colors are really only stored in one channel)? Now I don't know how you converted your picture, but: Instead of something like "convert 58632841.png test.png" (commandline), you could try "convert 58632841.png -type TrueColorMatte test.png".