Legacy ImageMagick Discussions Archive

Perhaps, in this case, but not far off. A bit of tweaking will fix that. Good stuff. Many thanks again. I made a few changes to my previous post, btw.

Thanks snigbo, greatly appreciated. With a better idea of the process, I'll play with it and see how it all shapes up. Bighter stars are often used as a reference for whitebalance in astro images. This region is somewhat dominated by the three blue giants shedding their luminance across the field. T...

Lots of stars... Orion. The belt region. The image is a stack of 21 frames. They are all dark subtracted, as well as bias subtraction and flat division before stacking. I see what you're doing. Interstingly, the red contribution is expected. The camera's IR filter has been removed and replaced with ...

Thanks. This is a half size jpg of the original linear tiff. I want to get rid of the muddy red/brown colour/gradient. I know there are other programs that do this, for this type of image. I'm interested in an IM solution to add to my work flow. I have tried various methods by following the document...

I would like to remove background gradients in images taken at night, where the background is a function of street light intensity and colour. Is the process described possible with IM. "Simple gradients can be effectively removed by creating an image containing only a smooth plane, with a slop...

The data behind the matrix may assume pixels values are linear, not sRGB (or AdobeRGB or whatever). If so, put "-colorspace RGB" before the matrix and "-colorspace sRGB" after it. That fits in with the workflow. Plan is to apply this to linear images. The 4th and 5th column seem...

Thanks. This is what I came up with. Works quite well. #! /bin/bash # Apply DSLR channel multipliers, obtained from # https://www.dxomark.com/Cameras/Canon/EOS-450D---Measurements # ImageMagick -color-matrix # To run script from command line in Windows OS replace \ with ^ AFAIK... # Canon 450D # R s...

Hi. Given the channel multiplier values R sRGB G sRGB B sRGB R raw 1.91 -1 0.09 G raw -0.19 1.65 -0.46 B raw 0.07 -0.7 1.64 Color matrix as defined in ISO standard 17321 Is there an IM method for applying multipliers to each channel, as follows? R = 1.91 * r - 1 * g + 0.09 * b G = -0.19* r + 1.65 * ...

Thank you. RGB Channel separation was problematic using -clone. 0 1 2 should equate to R G B but the channels appeared to have been swapped (when recombined). convert stack.tiff -separate %d.miff produces 4 channels. 4 being the alpha channel??? LAB channel separation didn't work with -clone - the d...

Version: ImageMagick 7.0.6-0 Q16 x86_64 2017-06-26 xubuntu 16.04 The following commands generate individual R G B L L* channels as well as combining into LRGB and L*RGB images. I have attempted a couple of -clone examples below combining lines 1, 2 and 3 and lines 4, 5 and 6 - working but buggy? Giv...

Of course!!! Thanks

Version: ImageMagick 7.0.6-0 Q16 x86_64 2017-06-26 xubuntu 16.04 Hi Is -clone the correct operator here? Single input image two outputs convert stack.tiff \( -clone 0 -depth 16 +compress -alpha off out.png \) -depth 16 +compress -alpha off out.tiff error convert: unable to open image 'out.png': Trie...

Thank you both. Forgot about escape parenthesis. The script works very well.

Most likely a bash thing but it complains about the brackets. Removing the brackets, file max.miff is not found and is not being used. I have tried this various ways, including swapping the Max and Min order. No max.miff file visible in folder and not being used. convert \ clone 0--1 *.$ext -evaluat...

Thanks for the pointers. This is a preliminary and working bash implementation of -poly combination of multiple images, rattled up over the weekend. I am interested in any IM tweaks that might improve the process; and while my bash scripting is quite basic, I am not asking for help with the script. ...