I just checked your advices.
1. result: rgb converting needs about 3/4 of the time of cmyk - this makes sense, because I have three instead of four channels. Good!
2. result: with an 508MB rgb .mpc file the extent option takes 1Minute and 3 seconds, the draw method needs 56 seconds. Well, ok, it is faster...
3. result: trying mogrify instead of using convert reduces the time to 29 seconds, but does not work. The image is unchanged.
This shows that most of the time is not used by the conversion but simply by reading and writing the image from/to disk.
How can I use the knowledge that draw does not need to copy the image if mogrify does not work.
Here is my code:
echo $right: rectangle 17853,0 17953,13465
echo $left: rectangle 0,0 100,13465
Code: Select all
time convert bild.mpc -fill blue -stroke black -draw "$left" -draw "$right" bild3.mpc
Code: Select all
time mogrify bild.mpc -fill blue -stroke black -draw "$left" -draw "$right"
By the way, you say IM uses Q16 for color conversion. Does this mean identify bild.mpc should say 16bit?
Because it doesn't:
bild.mpc MPC 17953x13465 17953x13465+0+0 8-bit DirectClass 508MB 0.780u 0:02.829
Or does it mean the conversion is done with 16bit but the image is still 8bit?
Greetings
Roland