Legacy ImageMagick Discussions Archive

IM 6.5.1-6 Q16 Mac OSX Tiger

I am curious why this does not work to make a fully transparent red image? It ends up fully opaque.

convert -channel rgba -alpha on -size 50x50 xc:"rgb(255,0,0,0)" red_trans.png

Neither does this:

convert -channel rgba -alpha on -size 50x50 xc:"rgb(100%,0%,0%,0)" red_trans.png


identify -verbose red_trans.png

Image: red_trans.png
Format: PNG (Portable Network Graphics)
Class: DirectClass
Geometry: 50x50+0+0
Resolution: 72x72
Print size: 0.694444x0.694444
Units: Undefined
Type: PaletteMatte
Endianess: Undefined
Colorspace: RGB
Depth: 16/1-bit
Channel depth:
red: 1-bit
green: 1-bit
blue: 1-bit
alpha: 1-bit
Channel statistics:
red:
min: 65535 (1)
max: 65535 (1)
mean: 65535 (1)
standard deviation: -0 (-0)
kurtosis: 0
skewness: 0
green:
min: 0 (0)
max: 0 (0)
mean: 0 (0)
standard deviation: -0 (-0)
kurtosis: 0
skewness: 0
blue:
min: 0 (0)
max: 0 (0)
mean: 0 (0)
standard deviation: -0 (-0)
kurtosis: 0
skewness: 0
alpha:
min: 65535 (1)
max: 65535 (1)
mean: 65535 (1)
standard deviation: -0 (-0)
kurtosis: 0
skewness: 0


Whereas this works:

convert -channel rgba -alpha on -size 50x50 xc:"#f000" red_trans.png

Try this command:

• convert -size 50x50 xc:"rgba(255,0,0,0)" red_trans.png

magick wrote:Try this command:

• convert -size 50x50 xc:"rgba(255,0,0,0)" red_trans.png

Right!!! How embarassing!