possible bug xc:color IM 6.9.7.7 Q16 Mac OSX
Posted: 2017-02-09T11:04:51-07:00
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Creating icc-colors with alpha is losing the alpha value.
alpha = 0.2 in the above
identify -verbose redalpha.png
There is no alpha channel.
Same is happening with srgb color as follows:
identify -verbose redalpha.png
EDIT: As snibgo points out below, in xc:"srgb(...)", I should have used xc:"srgba(...)". So no issue here.
Also he points out below a question as to whether icc-colors support alpha values. Of that I am not sure. So perhaps the IM developers can explain if it is suppose to be supported or not.
Creating icc-colors with alpha is losing the alpha value.
Code: Select all
convert xc:"icc-color(srgb,1,0,0.5,0.2)" redalpha.pngidentify -verbose redalpha.png
Code: Select all
Image: redalpha.png
Format: PNG (Portable Network Graphics)
Mime type: image/png
Class: DirectClass
Geometry: 1x1+0+0
Units: Undefined
Type: Palette
Endianess: Undefined
Colorspace: sRGB
Depth: 16-bit
Channel depth:
red: 1-bit
green: 1-bit
blue: 16-bit
Channel statistics:
Pixels: 1
Red:
min: 65535 (1)
max: 65535 (1)
mean: 65535 (1)
standard deviation: 0 (0)
kurtosis: 0
skewness: 0
entropy: nan
Green:
min: 0 (0)
max: 0 (0)
mean: 0 (0)
standard deviation: 0 (0)
kurtosis: 0
skewness: 0
entropy: nan
Blue:
min: 32768 (0.500008)
max: 32768 (0.500008)
mean: 32768 (0.500008)
standard deviation: 0 (0)
kurtosis: 0
skewness: 0
entropy: nan
Image statistics:
Overall:
min: 0 (0)
max: 65535 (1)
mean: 32767.7 (0.500003)
standard deviation: 0 (0)
kurtosis: 0
skewness: 0
entropy: nan
Same is happening with srgb color as follows:
Code: Select all
convert xc:"srgb(100%,0%,50%,0.2)" redalpha.pngCode: Select all
Image: redalpha.png
Format: PNG (Portable Network Graphics)
Mime type: image/png
Class: DirectClass
Geometry: 1x1+0+0
Units: Undefined
Type: Palette
Endianess: Undefined
Colorspace: sRGB
Depth: 16-bit
Channel depth:
red: 1-bit
green: 1-bit
blue: 16-bit
Channel statistics:
Pixels: 1
Red:
min: 65535 (1)
max: 65535 (1)
mean: 65535 (1)
standard deviation: 0 (0)
kurtosis: 0
skewness: 0
entropy: nan
Green:
min: 0 (0)
max: 0 (0)
mean: 0 (0)
standard deviation: 0 (0)
kurtosis: 0
skewness: 0
entropy: nan
Blue:
min: 32768 (0.500008)
max: 32768 (0.500008)
mean: 32768 (0.500008)
standard deviation: 0 (0)
kurtosis: 0
skewness: 0
entropy: nan
Image statistics:
Overall:
min: 0 (0)
max: 65535 (1)
mean: 32767.7 (0.500003)
standard deviation: 0 (0)
kurtosis: 0
skewness: 0
entropy: nan
Also he points out below a question as to whether icc-colors support alpha values. Of that I am not sure. So perhaps the IM developers can explain if it is suppose to be supported or not.
srgbA