Am 03.09.2021 um 18:24 schrieb Hans Hagen via ntg-context :

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Hi, is it possible to apply geometric transformations to images using MetaPost? This is again way over my head, but I’m still trying different methods to let a ConTeXt document look more “hand-made”. In my example*, I added frame and shadow to a photo and _distorted_ it slightly to have it look like a postcard was glued on the page (with a piece of tape). I’d like to automate and randomize that process. I guess I could achieve something similar with ImageMagick (not with GraphicsMagick), but if it would be possible inside LMTX that would be great.

On 9/3/2021 12:28 PM, Henning Hraban Ramm via ntg-context wrote: the question is not so much if it can be done but how far we should go in doing things .. so, only as friday afternoon distraction, and because i wanted to upload anyway (not done yet) i'll meta-imp-magick that uses the gm lib interface (that only does simple conversions, but i added bur and noise an dcan add some more if needed as long as there is no weird stuff or code bloat)

not in the core, just as 'imp' because we don't want library dependencies (and the optional libs are lightweight delayed loading ones)

now, the drawback of course is that one needs gm installed (quite large) but it does work on my windows box so ...

Thank you! That’s interesting and I can probably use it for a different project, but for what I had in mind, GM wasn’t enough. IM has much more features (and probably also flaws), is even bigger, with more dependencies, but I could install both with MacPorts. I guess it’s on me to write a wiki page about GM. And maybe adapt your code to IM... I just thought since MP is great for geometrical calculations it might also be able to use transformation matrices on images. But since I don’t understand matrix calculations anyway, I’ll live without. Generally, I’d like to delay image manipulation as long as possible – only ConTeXt knows the final size of the used images, and since I want to keep e.g. frames and shadows at the same size for all images I need to calculate with that final size. Hraban

Am 04.09.2021 um 19:06 schrieb Hans Hagen :

On 9/4/2021 2:18 PM, Henning Hraban Ramm via ntg-context wrote:

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I guess it’s on me to write a wiki page about GM.

you can then also add some comparison with im (i.e. what does it offer more than gm)

Oh no... IM and GM have a history, and I don’t want to get involved. GM accuses IM of security issues, feature and dependency bloat, bad code quality, inefficiency, frequent API changes, license changes and whatnot. OTOH IM offers much more features (e.g. the geometric transformations I inquired about), and you can find lots of interesting examples (including the scripts Bruce mentioned). I couldn’t find another CLI tool that can do most of these things, at least not with much more programming. Dependencies according to MacPorts: Full Name: GraphicsMagick @1.3.36_1+q8 Library Dependencies: libxml2, bzip2, xz, zlib, libpng, tiff, freetype, libiconv, libtool, lcms2, jasper, libjpeg-turbo, webp Full Name: ImageMagick @6.9.11-60_1+x11 Library Dependencies: bzip2, djvulibre, xz, jbigkit, libjpeg-turbo, lcms2, libpng, libraw, tiff, webp, zlib, fftw-3, freetype, fontconfig, ghostscript, libiconv, libtool, openjpeg, openexr, expat, libxml2, libheif, pkgconfig, xorg-libX11, xorg-libXext, xorg-libXt Runtime Dependencies: urw-fonts It’s probably not wise to run IM in a web server process for security and efficiency reasons, but if I run it only on my own computer there shouldn’t be a problem. BTW, here’s my script: #!/bin/bash #INPUT=$1 OUTPUT=${INPUT/.JPG/.png} OUTPUT=${OUTPUT/.jpg/.png} OUTPUT=${OUTPUT/in\//out\/} # random rotation ±1.5˚ ROTATION=`jot -r 1 -1.5 1.5` echo $OUTPUT ${ROTATION}˚ # downscale, add a white border and a shadow, rotate, move down, add a piece of tape (tesa1.png), grayscale convert "$INPUT" \ -auto-orient \ -resize 800x800 \ -bordercolor white -border 10 \ \( +clone -background black -shadow 80x3+2+2 \) +swap \ -background transparent \ -layers merge \ -rotate ${ROTATION} \ +repage \ -gravity north \ -splice 0x10 \ \( tesa1.png -resize 200x50! \) -compose Multiply -composite \ -colorspace Gray \ "$OUTPUT" Here are some results: https://sedna.fiee.net/d/2c3218730f8341aab1fa/ Hraban

Am 05.09.2021 um 10:10 schrieb Hans Hagen :

On 9/5/2021 9:40 AM, Henning Hraban Ramm via ntg-context wrote:

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Am 04.09.2021 um 19:06 schrieb Hans Hagen :

On 9/4/2021 2:18 PM, Henning Hraban Ramm via ntg-context wrote:

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I guess it’s on me to write a wiki page about GM.

you can then also add some comparison with im (i.e. what does it offer more than gm) Oh no... IM and GM have a history, and I don’t want to get involved. GM accuses IM of security issues, feature and dependency bloat, bad code quality, inefficiency, frequent API changes, license changes and whatnot.

ah, i think i remember ... i switched to gm just because im didn't run well at that time on windows

personally i think that "accuses of .." show that down side of the open source community (which includes the tex community btw) ... it gets even worse when something sells itself for big money and then after a few years spins off again attacking those who paid them ... i suppose that unconstrianed social media also play a role in this (one reason why i'm not really interested in discussions around this in public)

I hear you. Of course there are reasons to be opinionated and to fork some open source projects if they move into a direction that you don’t like. But that doesn’t mean you can’t be polite about it. And the GM maintainers focus too much on their hate for IM’s developer(s) for my taste. Maybe it helps them to stay focused and write better code if they have an enemy...

(what to think of: https://www.youtube.com/watch?v=BhTQyeEdnzs)

The video doesn’t run for me, just read the description: I’m sure the problem exists, but it’s maybe exaggerated?

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Dependencies according to MacPorts: Full Name: GraphicsMagick @1.3.36_1+q8 Library Dependencies: libxml2, bzip2, xz, zlib, libpng, tiff, freetype, libiconv, libtool, lcms2, jasper, libjpeg-turbo, webp

makes me wonder if there is some simple image manipulation lib that just deals with the pixels .. we don't need xml, freetype, libiconv, ...

Maybe use these libs (libpng etc.) directly? I don’t know what they can do. Is there a Lua lib that parallels Python’s Pillow? It also has a lot of dependencies to support image formats or add features, but most of them are optional, see https://pillow.readthedocs.io/en/latest/installation.html#building-from-sour...

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Full Name: ImageMagick @6.9.11-60_1+x11 Library Dependencies: bzip2, djvulibre, xz, jbigkit, libjpeg-turbo, lcms2, libpng, libraw, tiff, webp, zlib, fftw-3, freetype, fontconfig, ghostscript, libiconv, libtool, openjpeg, openexr, expat, libxml2, libheif, pkgconfig, xorg-libX11, xorg-libXext, xorg-libXt Runtime Dependencies: urw-fonts

hm, that looks bad ... maybe not have a look after all ... i get the impression that many originally small programs get bloated by pulling in one lib that then pulls in more,

Exactly. The criticism by the GM maintainers probably *is* justified. (When I installed IM, actually all of the dependecies were already installed for other programs.)

even if nothing of that is used or useful to the task (we sort of had that when luatex used xpdf from which we only need the reading part but we could not really complain about that because it has been so from the start but it triggered quite a bit of updating)

It might make sense for some projects to dive into these libs and pull out and combine the parts that they really need. Even if that’s against the meaning of shared libraries and makes it harder to watch upstream for security fixes...

keep in mind that we can just call them as programs using os.execute (or the filter module or ...) ... no need to waste time in integration (apart from a fun aspect)

Of course. I never wanted to suggest integrating GM, IM or whatever.

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It’s probably not wise to run IM in a web server process for security and efficiency reasons, but if I run it only on my own computer there shouldn’t be a problem.

hm, why not? all it does in the end is "bits in - bits out"

Apparently there were bugs in IM that bite web developers – if you used IM via PHP and allowed users to upload arbitrary images (e.g. avatars), they could exploit buffer overflows or something like that to hack your system. Or at least stall it (DoS attack).

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BTW, here’s my script: Here are some results:

Did you try that with the filter module? It would make it more portable

I completely forgot I could do that (and I even know how). Working on too many building sites at the same time... Hraban

Am 06.09.2021 um 04:13 schrieb Aditya Mahajan via ntg-context :

On Sun, 5 Sep 2021, Henning Hraban Ramm via ntg-context wrote:

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Am 05.09.2021 um 10:10 schrieb Hans Hagen :

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BTW, here’s my script: Here are some results:

Did you try that with the filter module? It would make it more portable

I completely forgot I could do that (and I even know how).

See attached. Basically, you can just copy-paste your script as the value of the filtercommand, and that's it.

Thank you! I could have done it myself... But Hans was in a generous and experimenting mood and wrote - Lua code interfacing GraphicsMagick to manipulate bitmap data - a MP interface to ImageMagick I just need to test them and will report.

PS: I realized that there is a regression, and \externalfilterbasefile does not remove the file extension. So, the output is named mill.png-taped.png rather than mill-taped.png. I'll look into it later

Oh, thank you. I need to check in my LilyPond setup. Hraban