Legacy ImageMagick Discussions Archive

It can be done many ways. You could use ffmpeg to split a video into frames then resize each frame in image magick, or directly from avisynth with callcmd plugin or some such to externally process frames.

Just wanted to mention, if you want an equalizer for images try http://www.avisynth.nl/users/vcmohan/FF ... Quiver.htm

It just so happens I was just reading about this. Try to search "natural image matting". One top solution is called "Spectral Matting". There's a paper and Matlab source code, so this isn't an easy solution, it's for programmers. I believe such operations are available in high-end video editing ...

Thanks, the key phrase here is "3 points which define a circle". You can find two types of answers, one gives radius as a formula, another uses matrices. Code for such solutions can be found in graphics gems.

Thanks for the help, I processed a few images, but have moved on to a custom solution programmed in Python with a stats package.

ok, thanks for the tip, here is sample code to process in a loop, using the scripting in cmd.exe (windows) @ECHO OFF rem for loops in a batch file, over filenames rem this is required to do for loops (setting variables within the loop) SETLOCAL ENABLEDELAYEDEXPANSION rem for loop, for %%f in (set ...

I was trying to magick identify *.tif on hundreds of images, and found that magick buffers all the images into ram first and it's very slow. Certainly this simple operation could be much faster. I recall something about setting the buffer size for magick, that might help as well. But I would call ...

It seems to me I only need the start and end points of two arcs to be able to solve for radius. I'll have to spend some time working out the formula. (to within a flip or sign).

ps I could isolate just one short curved arc, finding the radius of curvature of that would help, but I was hoping to average over a few arcs for better accuracy. The ensemble has to be a best fit. So if you want the simplest example and explanation of mh problem, just picture a short arc, and ...

I have an image with multiple coecentric arcs, of the same curvature. The question is to find the origin of the the circles which produce them. Imagine drawing centered coeccentric circles at origin x,y, of random radius. Then take some random square area of that, so it contains some arcs. Then find ...

Ugh. Sorry to be so confused, but now you're presenting me with yet a 3rd model of what it's doing. I made a typo above, I meant magick -size 10x10 canvas:white -transparent white PNG32:out2.png Put it this way, I want a white image1, with opaque alpha, and white image2, with transparent alpha. To ...

so you're saying magick out1.png -set alpha -channel a -separate +channel alpha1.png magick: unable to open image 'a' strangely, when I do magick identify -verbose out1.png I can see that the out?.png have alpha channels, and even that the opaque out1.png shows gray=255 and alpha=255 and out2, the ...

Thanks! I get it now. My understanding was that -opaque white was "marking" white image pixels as opaque in the alpha channel. Now my understanding is that it's "converting" white pixels to opaque, leaving behind ... nothing, which is why you need a -fill. To make it work as I thought, you just ...

I'm trying to work this out myself and understand how transparency works, it should be easy but a simple experiment isn't working. magick -size 10x10 canvas:white -opaque white PNG32:out1.png magick out1.png -channel a -separate alpha1.png magick -size 10x10 canvas:white -transparent white PNG32 ...

So like this? magick IMG_2021.tiff IMG_2022.tiff -compose difference -composite -fill white +opaque black comp1.png magick IMG_2021.tiff IMG_2023.tiff -compose difference -composite -fill white +opaque black comp2.png magick comp1.png comp2.png -compose lighten -composite comp3.png Also, is there a ...