Converting to 1-bit

Library of images to use as OFFIMG screens on the DM41X and DM42
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Do you have a creative streak? Post your OFFIMG photos here.

Images MUST be in Windows-NT .bmp format at a resolution of 400x240 pixels and 1-bit colour depth or they will not be displayed by the DM42. Images that do not meet this requirement will be removed from the forum :)
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BestofTimes
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Converting to 1-bit

Post by BestofTimes »

What tools have you found useful to convert images to 1-bit bitmaps?

I've used Photoshop’s Diffusion Dither option to switch greyscale files to bitmaps but the results can sometimes be a bit hit and miss. What do you guys use?
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toml_12953
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Re: Converting to 1-bit

Post by toml_12953 »

BestofTimes wrote:
Mon Dec 02, 2019 9:57 pm
What tools have you found useful to convert images to 1-bit bitmaps?

I've used Photoshop’s Diffusion Dither option to switch greyscale files to bitmaps but the results can sometimes be a bit hit and miss. What do you guys use?
I use GIMP for Windows
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tgray
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Re: Converting to 1-bit

Post by tgray »

Photoshop for initial cropping and then a python script I wrote for the mono conversion and final dithering.

I always loved the way Atkinson dithering looked. It reminds me of being a kid and playing on the classic Macs at my dad’s work. So I implemented it for myself when I got a DM42. Fun learning project.

My code is here for anybody who wants it:
https://github.com/tgray/hyperdither
Thomas Okken
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Re: Converting to 1-bit

Post by Thomas Okken »

I like the pgmtopbm tool from the Netpbm suite. The Netpbm suite is extremely old-school, it's a bunch of command-line tools, but well worth the time to familiarize yourself with.
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BestofTimes
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Re: Converting to 1-bit

Post by BestofTimes »

I found the best results in an old copy of Paint Shop Pro at work using these settings.

Image
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Jaymos
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Re: Converting to 1-bit

Post by Jaymos »

I have a long list of image processing software available on both Mac and Win, but I prefer and use the free IrfanView + free add-on pack for this. On Mac, Winebottler is needed to make an app, and the app works well including cut and paste. In my opinion it’s my Swiss army knife equivalent for many many years already.
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reavy
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Re: Converting to 1-bit

Post by reavy »

tgray wrote:
Tue Dec 03, 2019 1:07 am
Photoshop for initial cropping and then a python script I wrote for the mono conversion and final dithering.

I always loved the way Atkinson dithering looked. It reminds me of being a kid and playing on the classic Macs at my dad’s work. So I implemented it for myself when I got a DM42. Fun learning project.

My code is here for anybody who wants it:
https://github.com/tgray/hyperdither
I found this thread while looking for tools to easily convert to 1-bit BMPs for my DM42. I had good luck with tgray's hyperdither. I forked it and made a small revision to get it to work with Python 3. Here for anyone who is interested: https://github.com/bpburns/hyperdither
STS-741
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Re: Converting to 1-bit

Post by STS-741 »

I use Pierre-Emmanuel Gougelet's XnView (Ver. 2.49.4) software for this, which is available as freeware for several operating systems. It's easy to use and has been translated into 46 languages. The program is also freely available in a portable version. 8-)
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revwillie
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Re: Converting to 1-bit

Post by revwillie »

Just found that XnConvert (also from XnView) will take a 1 bit monochrome bitmap from GIMP and 'correct' it for viewing in my DM42.
I don't know what the new version of GIMP is doing wrong, but the files won't display unless I run them through XnConvert and re-save them.
I set up a 'clean metadata' action for the comments field which was never populated. Then the output file works fine in the DM42.
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Sassersson
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Re: Converting to 1-bit

Post by Sassersson »

Imagemagick usually gets pretty good-looking results. I don't have a DM42 to test them with yet (trying to restrict my spending), but at 400×240 they're the same size as the default OFFIMG's.
convert in.png -flatten -alpha remove -dither floydsteinberg -monochrome out.bmp
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