Legacy ImageMagick Discussions Archive

I don't know why you have the "-intensity" setting in your command. What do you want it to do? I just want to manipulate both linear and nonlinear grayscale images, so I need to know the basics of how IM decides whether a given grayscale image contains linear or nonlinear values! I believ...

Your first and third images don't show for me. You don't say how you made the first, myrosesgray.jpg, so I can't reproduce your results. Sorry, can you see those images now? (The phenomenon *should* occur with almost any true grayscale jpg as input, like any grayscale version of rose: saved by IM7,...

I'm not sure whether this is by design (perhaps undocumented?) or a bug. The documentation for "-intensity" says that it determines how a grayscale image is calculated from a color image, and in some other cases when a single intensity needs to be calculated internally from three channel i...

Meanwhile, I can't think of any pre-processing that would cover all circumstances. Your image has only positive values, with most values near zero and a very long thin tail of high values, so "multiply to make the mean 50%" is a sensible solution. An hdri image is typically well-spread-ou...

When performing "-colorspace RGB" on a linear (gamma=1) Gray image, the result changes the data values (while replicating them to three channels) to nonlinear values (as if the result were going to be marked as sRGB?) even though it sets the image as linear RGB and preserves the gamma=1 se...

magick wrote: ↑2017-08-10T06:02:48-07:00 Thanks for the problem report. We can reproduce it and will have a patch to fix it...

Thank you very much.
In addition to preserving the gamma setting of the image, will -combine on three gamma=1 gray images produce linear RGB as the colorspace of the result instead of sRGB?

When the colorspace is linear RGB with gamma=1, the operators -separate and -combine ignore all of that and mark their output as nonlinear (colorspace gray for -separate or colorspace sRGB for -combine) with gamma~0.4545... In the following, -separate is changing the marked gamma from 1 to 0.454545 ...

Can anyone out there try it with an HDRI Windows build? Sounds like the values aren't being clamped properly in these HDRI Windows builds. I don't use imdisplay. But the image does show as I would expect using imdisplay in both v6.9.5-3 and v7.0.3-5, Q16, non-HDRI, on Windows 8.1, if that's any help.

Would anyone please try opening the mentioned memorial.hdr file in display.exe under Windows (with HDRI and/or not)? I've now *also* tested it on a Non-hdri Cygwin ImageMagick 6.9.1-3 Q16 i686 2015-06-21 (DPC OpenMP) (Cygwin 2.0.4 32-bit) and the issue does *not* occur there. Fred already said the i...

Perhaps you should upgrade your IM to the latest version. 7.0.2-9 is 36 versions old. As in my original post as well as in the one you are responding to (& my sig btw), i am using 7.0.6 x64 Windows. I said that I *also* reproduced the problem in 7.0.2 x86 32bit for Windows. I'm still hoping som...

Can anyone on Windows reproduce the error? (especially with your Q16 HDRI-enabled IM)

In addition to IM 7.0.6-2 Q16 HDRI x64, I can reproduce the error on 32-bit IM 7.0.2-9 Q16 HDRI x86 2016-08-14

When this image is opened in imdisplay www.pauldebevec.com/Research/HDR/memorial.hdr the supra-white (> 1.0) pixels are not clamped to white but are instead mangled to seemingly-random colors. (Maybe an integer overflow or something like that?) It displays fine if you first convert it to EXR format....

snibgo wrote: ↑2017-07-30T17:02:27-07:00 The nip2-IM interface was included with nip2, as a (long) menu option. Perhaps it still is, though I see IM is now included in the VIPS binary.

BTW, I just noticed that there's also a VIPS-based wysiwyg non-destructive (operation-accumulating) image editor called PhotoFlow.

"-set colorspace None" had never occurred to me. Sadly, it seems to have no effect: Oh, look, "Undefined" seems to work (even though it isn't listed in -list colorspace): magick rose: -set colorspace Undefined info: rose: PPM 70x46 70x46+0+0 8-bit 9673B 0.000u 0:00.003 But presu...

My editor is called "Swim", it works on Windows, and I haven't published it. Sounds interesting -- maybe it's worth distributing even if it's with the understanding that it's "as-is" and "for techies". Lazy evaluation, oh, yes please. Have you seen VIPS and nip2 ? I wr...