Legacy ImageMagick Discussions Archive

I keep hearing a lot about the mythical IMv7. Any idea when that's going to come out or at least when we'll see a beta?

IM (using 6.6.9-7) seems to have some major problems with resizing or any sort of color quantization when using certain colorspaces, especially the Luma-based ones. Here's the code used: convert -list colorspace | while read CS; do echo $CS && convert -monitor Lenna.png -depth 32 -colorspace $CS ...

The way IMv6 handles 'sRGB' colorspace is actually reversed. That is to say specifying "-colorspace sRGB" converts a image from sRGB to RGB, and visa-versa. That is "-colorspace sRGB" actually converts an image from sRGB to linear RGB colorspace. This was the result of IM choosing RGB as its ...

Update: Version that mostly works with LMS, using a XYZ to LMS conversion. For some reason, this doesn't appear to work with the Deuteranope version. I suspect there's some clipping going on that I don't know how to disable. # Normal convert -monitor Lenna.png -background Orange label:Normal ...

This is a well know BUG, and is caused by two separated steps that were never optimized for small numbers of colors. First quantization step, as far as I can tell actualy does generate 256 colors! (255 is transparency is needed) However when dithering is then used to change the image to use those ...

For others interested, this works: # Protanope = reds are greatly reduced (1% men) convert -monitor Lenna.png -strip -depth 32 -colorspace sRGB -color-matrix '0.0 2.02344 -2.52581 0.0 1.0 0.0 0.0 0.0 1.0' +set profile Lenna-CBP.png # Deuteranope = greens are greatly reduced (1% men) convert -monitor ...

Yeah, 10fps is about the max you can get on a GIF, anyway. So, the main problem is the 5 seconds for 66 frames during the save? Do you have any way to isolate that down even further? Somewhat within the save process? If not, it might be worth trying out a few different versions of IM, including one ...

Okay, I'm pretty much done with my research and done tweaking my code. This method of video to GIF will achieve both the best quality and good size compression. Obviously, figures can be adjusted to move towards one or the other, but I'll cover some of that as well. On average, a 8fps GIF at a width ...

Hmmm, yeah, only 3 colors changes things. BTW, F-S is Floyd-Steinberg, the type of dither. It's an error-correction dither, so it'll be random. Heck, for 3 colors, just turn off dither. No need for it. Let's talk about frames, then. What's the frame delay? Are we talking 60 frames for 6 seconds? How ...

Wait, hold on. The slowdowns make sense, and your choice of quantization parameters confuse me. First, from the manual: classType - Image storage class. Note that conversion from a DirectClass image to a PseudoClass image may result in a loss of color due to the limited size of the palette (256 or ...

What's the full code of options? I've plenty of experience with anim GIFs, but on my end, it's mostly about getting the best quality of video conversion, rather than speed.

Yes, but if I had "-colorspace sRGB -colorspace Lab", would that convert the input image from RGB to sRGB to Lab, or just RGB to Lab?

Also, were you interested in that C program for creating perfect ordered-dither maps of any shape?

Also, ImageMagick seems to "hang on" to as much detail about the colors as possible to prevent information/color loss, instead of just following what I say in the order I say it. Hence, I have to do this pipe operation. If combined, it would simply convert to 32-bit Lab and resize everything ...

Not my meaning. By 'random set of colors' I mean a set of colors that was selected by some quantization algorithm to best represent the image. that is provide more colors to 'shades' and less colors to the 'single odd-colored pixels'. But the final set of colors to use is essentially not 'ordered ...

There seems to be a boundary point at 16*BD*331=84,736 (for a bit depth of 16, with a max BD of 16). If passed a -colors option above this point, it will immediately process all of the colors up to that point and then VERY SLOWLY increment by one, even going down a bit before eventually going up ...