Legacy ImageMagick Discussions Archive

Another simple round-trip test RGB -> Lab-> txt_file -> RGB: %I%convert ^ -size 1x10 ^ gradient:rgb(0%%,100%%,100%%)-rgb(100%%,100%%,0%%) ^ -write rgb0.png ^ -colorspace Lab ^ -write txt:lab_text.txt ^ +delete ^ lab_text.txt ^ -set colorspace Lab ^ -colorspace sRGB ^ rgb1.png %IM%compare -metric RMS...

Your fx can be replaced by suitable composites. See http://www.imagemagick.org/Usage/compose/

One way around clipping is to use HDRI, then "-auto-level".

Yes, that shows the problem. I have reddened the incorrect values, for just the Q16 version. The corresponding hex values are also wrong. # ImageMagick pixel enumeration: 1,10,65535,srgb 0,0: ( 0,65535,65535) #0000FFFFFFFF cyan 0,1: ( 7282,65535,58253) #1C72FFFFE38D srgb(11.1116%,100%,88.8884%) 0,2:...

The command would be: convert *.JPG -evaluate-sequence max max.jpg No hyphen between "-evaluate-sequence" and "max", and this comes after the input filename. At 6 bytes/pixel, you need 9.6 GB for the input images. If you don't have enough RAM, it should use disk. If you run out o...

I haven't come across "--sequence-max", and it doesn't work on ImageMagick 6.8.6-0 on Windows, and isn't documented. Perhaps you mean "-evaluate-sequence max".

Perhaps you are running out of memory. How many images, and how many pixels in each one?

Is the printing area rectangular, as in your original example? Finding those dimensions can be done very quickly.

Yes, ImageMagick is written in C. I believe IM colorspaces "Lab and "CIELab" are the common version, CIELAB, CIE 1976 (L*, a*, b*). See http://en.wikipedia.org/wiki/CIELAB . However, values in IM Q16 are integers from 0 to Quantum (which is 65535 for Q16), and the zero or neutral valu...

There seems to be a bug writing txt: format from Lab images, in IM versions dating back to v6.8.0. IM writes and reads integers with an offset of Quantum/2, but negative values are written as zero. Thus writing a Lab txt file and reading it back in will yield different values. When reading txt files...

Scaling your example up x10, so 3000x3000 pixels, took only 2 minutes. Do you have a memory problem?

If you provide your actual image, and explain what you need, you might get better advice. (But I don't do Perl.)

... so skin in shadow is still not selected because that is darker brown-green or midtone. And 200/200 is still similar. So this looks like the fuzz calculates not only with color but aso with amount of light. Yes. Remember that fuzz uses all the channels. It measures distance in 3-dimensional spac...

Yes, morphology "erode" is the obvious method. It handles anti-aliasing. Windows code: %IM%convert -size 300x300 xc:none -fill none ^ -stroke blue -strokewidth 10 -draw "roundrectangle 10,10 50,50 5,5" ^ -stroke red -strokewidth 20 -draw "roundrectangle 110,110 150,150 5,5&q...

The printer driver on your computer will translate from sRGB to CMY or CMYK or whatever the physical printer wants. The driver software will probably also ask about the paper stock. Alternatively, you could use ImageMagick to convert the file to CMY(K) with the profile that is appropriate to your pr...

On Windows and a recent version of IM, if I put Inkscape's directory on the PATH, convert will automatically use Inkscape.

ImageMagick is open source, so you can see how it works. I suggest you read up on colorspaces. In IM, fuzz is a distance within a colorspace. A colorspace typically has 3 dimensions: RGB, CMY or Lab. One has 4 dimensions: CMYK. If you paint, you probably work with more colours. If you are writing yo...

"display: Ignoring incorrect gAMA value .20661 when sRGB is also present `t.png' @ warning/png.c/MagickPNGWarningHandler/1777" isn't an error but a warning. (It says "warning" near the end.) You can shift gamma if you want, but (depending on the operations) it may be more technic...