[magick-users] composite Dst_In transparency problem

[Anthony Thyssen]

=?iso-8859-1?Q?G=FCnter?= Bachelier on  wrote...
| Hello,
| 
| I have a problem concerning composite: after the composing with
| Dst_In the parts that were transparent in the mask were in the
| result image black:
| 
| convert -size $triangle_widthx$triangle_width -stroke red -fill red
| -draw "polyline 1,1 $triangle_width,$triangle_width 1,$triangle_width"
| xc:none p4m_mask.png
| convert -crop $triangle_widthx$triangle_width+$x4+$y4 image.jp2
| image_p4m.png
| composite p4m_mask.png image_p4m.png -compose Dst_In p4m_G1.png
| 
| A correction of the result with "-transparent black" would change all
| parts.
| How can the transparency be preserved?
| 
| Perhaps "-clip-mask" could be used, but I did not find a dokumentation
| that helped me.
| 
You original image did not have an alpha channel to save the
transparency into!

Add a  -matte  after reading in the images.

Also it is a good idea to actually create your image BEFORE trying to
-draw or -crop them.


Read the section on 'Legacy Mode' in IM Examples, Basics.


  Anthony Thyssen ( System Programmer )    <A.Thyssen at griffith.edu.au>
 -----------------------------------------------------------------------------
      `` I want my skin to be its yellowist! '' -- Bart Simpson
 -----------------------------------------------------------------------------
     Anthony's Home is his Castle     http://www.cit.gu.edu.au/~anthony/