## Search found 8 matches

2018-11-09T15:01:49-07:00
Forum: Users
Topic: Reducing Alpha during multiply
Replies: 11
Views: 4658

### Re: Reducing Alpha during multiply

If your image already has transparency, then -evaluate set will make it all that value. So you need to reduce the existing opacity/transparency by mutiplication. try for 50% reduction, multiply by 0.5 -delete 0 ( -clone 0 ( C1_L5_017.png -alpha on -channel a -evaluate multiply 0.5 +channel ) -compo...
2018-11-09T14:09:09-07:00
Forum: Users
Topic: Reducing Alpha during multiply
Replies: 11
Views: 4658

### Re: Reducing Alpha during multiply

-delete 0 ( -clone 0 ( -alpha on -channel a -evaluate set 50% C1_L5_017.png ) -compose multiply -composite ) To which image do you want to apply the reduced alpha -- the -clone 0 or the C1_L5_017.png First off I REALLY appreciate the help you've provided so far. You're saving my life. I have one ot...
2018-11-09T13:29:25-07:00
Forum: Users
Topic: Reducing Alpha during multiply
Replies: 11
Views: 4658

### Re: Reducing Alpha during multiply

try putting your processing after the reading the image you want it to be applied. -delete 0 ( -clone 0 ( C1_L5_017.png -alpha on -channel a -evaluate set 50% ) -compose multiply -composite ) Yeah, I preemptively tried that. Still getting an argument error for set. Your example (with no +channel): ...
2018-11-09T13:17:24-07:00
Forum: Users
Topic: Reducing Alpha during multiply
Replies: 11
Views: 4658

### Re: Reducing Alpha during multiply

The latter, the C1_L5_017.png.

To be clearer, I want to multiply layer a with layer b, and before/during that I want to reduce opacity of layer b to 50%.
2018-11-09T13:12:59-07:00
Forum: Users
Topic: Reducing Alpha during multiply
Replies: 11
Views: 4658

### Re: Reducing Alpha during multiply

What is your Imagemagick version, date and platform/OS? The command should be convert image.png -alpha on -channel a -evaluate set 50% +channel result.png Sorry, I forgot to add the -channel a above and have edited it to correct it. http://www.fmwconcepts.com/misc_tests/lena.png convert lena.png -a...
2018-11-09T13:00:46-07:00
Forum: Users
Topic: Reducing Alpha during multiply
Replies: 11
Views: 4658

### Re: Reducing Alpha during multiply

Add -alpha on -evaluate set 20% +channel after the image you want to reduce its opacity Hm, I'm having a bit of trouble making this work. So first I just tried to apply it to one image, to see what I was working with. convert C1_L5_017.png -alpha on -evaluate set 50% +channel foo.png But the result...
2018-11-08T22:06:54-07:00
Forum: Users
Topic: Reducing Alpha during multiply
Replies: 11
Views: 4658

### Reducing Alpha during multiply

Hey all, I got a bit of a problem. We have some software that programmatically combines several pngs into a jpg, using a combination of 'over' and 'multiply' conversions. convert ( L0_Leg_Metal_Arc_Chrome.png Sofa_C1_L1_001.png -compose over -composite ) ( -clone 0 C1_L2_001.png -compose over -compo...
2018-10-18T15:02:38-07:00
Forum: Users
Topic: compose "over" + convert png->jpg + white background
Replies: 1
Views: 2160

### compose "over" + convert png->jpg + white background

Hey imagemagick dudes, I'm struggling here to figure out what I'm doing wrong. So first I just wanted to compose two png layers over one another and convert to jpg: convert ./1.png ./2.png -compose over -composite 3.jpg This works fine, but the background is black, and I want it to be white. I found...