Legacy ImageMagick Discussions Archive

It is not a parenthesis is problem. It gives the same solution because subtraction come later than division. I think I found the solution converting to text file: convert image.png image.txt convert d0-2017-10-13.jpg -separate -delete 1 -fx '((u[1]*255/231-u[0]/ u[1]*255/231+u[0])+1)/2' d0ndvi.png r...

Near the plants, I putted a white target that I cropped in white.jpg. convert white.jpg -resize 1x1\! -format "%[pixel:u]\n" info: >white.txt white.txt contain this text line: srgb(255,170,231) I tried to make a white balance adding *255/231 to the blue channel and follow fmw42 suggestion....

Thank you for your reply. Yes, adding 0.5 gives a brighter images but with different contrast. The range of Ndvi index should be between -1 and 1; I was wondering how the different commands 'convert' it in the range of 0-255 values. I'm going to compare a series of images of differently fertilized p...

I'm trying to calculate the ndvi index using imagemagick in spite of proprietary software, but I obtain different results using different methods with the same mathematical expression. In a linux console: convert d0-2017-10-13.jpg -separate d0-%d.png convert d0-0.png d0-1.png d0-2.png -fx '(u[2])-(u...

I can' find how to convert my table in a format useful for netpbm

Hi, this is my first post. Debian 8, imagemagick gui do not work. I need to compute ndvi from a jpg photo. https://it.wikipedia.org/wiki/Normalized_Difference_Vegetation_Index I converted jpg in txt by terminal commands: convert filtrorosso.jpg filtrorosso.txt sed -e 's/ //g' -e 's/(//g' -e 's/)//g'...