macOS app Retro Dither creates EXCELLENT BMP files

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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48GX
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macOS app Retro Dither creates EXCELLENT BMP files

Post by 48GX »

I have been creating a lot of OFFIMG lately. This lead down a deep rabbit hole and exposed a serious problem for those of us on macOS. Photoshop was my only real way to create a BMP file suitable for the DM42. Photoshop can do an "okay" job on certain photos, but for the vast majority of the photos I was choosing and converting it was not good enough.

I then tried Gimp and was disappointed with the results. I searched the App Store for an app that would dither and export to BMP. HyperDither was mentioned here before and I gave it a whirl. I eventually had this as part of my workflow before entering Photoshop for the final conversion. Still, I found the lack of a true BMP export to be puzzling and too cumbersome.

Enter Retro Dither. I contacted the developer and made some suggestions. He responded and was very positive with my feedback and requests. I am proud to say that there is an app on the App Store that will now export an image to BMP format! Not only that, it will allow you to chose a DPI setting when exporting. Most conversion apps default to 72 PPI and do not have anyway to adjust this. Retro Dither does.

I would encourage anyone using a Mac to give it a shot. I find it does an excellent job.

Notes
  • You will need to crop and size your image to 400x240 @ 70 PPI before dragging into Retro Dither. This may be resolved in the near future. Maybe not. An easy enough task to do regardless.
  • Don't forget to set the PPI to 70 when you export the file.
Below are a few examples I pulled from the web, cropped and resized, and then converted using Retro Dither.
Attachments
North by Northwest with Cary Grant
North by Northwest with Cary Grant
NxNW-400x240.bmp (12.25 KiB) Viewed 716 times
Muhammad Ali vs Sonny Liston
Muhammad Ali vs Sonny Liston
Ali-400x240.bmp (12.25 KiB) Viewed 716 times
Marylin Monroe
Marylin Monroe
Marilyn-Monroe.bmp (12.25 KiB) Viewed 716 times
HP48GX since 1994
DM42, HP42s, DM41X, HP35s, DM41L
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48GX
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Re: macOS app Retro Dither creates EXCELLENT BMP files

Post by 48GX »

A few more examples.
Attachments
Johnny Cash at Folsom Prison
Johnny Cash at Folsom Prison
johnny-cash.bmp (12.25 KiB) Viewed 711 times
Moon-Landing.bmp
Moon-Landing.bmp (12.25 KiB) Viewed 711 times
Apollo 1 Buzz Aldrin Boot Print
Apollo 1 Buzz Aldrin Boot Print
Apollow1bootprint.bmp (12.25 KiB) Viewed 711 times
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rprosperi
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Re: macOS app Retro Dither creates EXCELLENT BMP files

Post by rprosperi »

The clarity and visual quality of these images continues to improve, these most recent ones are amazing. Thanks for the continued effort to improve the 'art' of making the art.
--bob p

DM42: β00071 & 00282, DM41X: β00071 & 00656, DM10L: 071/100
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Dan Simpson
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Re: macOS app Retro Dither creates EXCELLENT BMP files

Post by Dan Simpson »

Thanks for the tip on RetroDither. I look forward to trying it out.
Downloading now...
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My Collection: HP-55, HP-67 (Teenix Mod), HP-15C, HP-16C, HP-41CV, HP-41CX, SY41-CL (x2), DM41X (Beta), DM42, HP-42S, HP-48G, HP-71B (x2), HP-75C, HP-150.
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48GX
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Re: macOS app Retro Dither creates EXCELLENT BMP files

Post by 48GX »

More quick conversions.

I added the quote to the Einstein image.
Attachments
Zebras.bmp
Zebras.bmp (12.25 KiB) Viewed 647 times
enterprise-tng.bmp
enterprise-tng.bmp (12.25 KiB) Viewed 647 times
Albert-Einstein.bmp
Albert-Einstein.bmp (12.25 KiB) Viewed 647 times
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48GX
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Re: macOS app Retro Dither creates EXCELLENT BMP files

Post by 48GX »

Three more...
Attachments
RAAF-F-35A.bmp
RAAF-F-35A.bmp (12.25 KiB) Viewed 635 times
tiananmen-square.bmp
tiananmen-square.bmp (12.25 KiB) Viewed 635 times
Great-White.bmp
Great-White.bmp (12.25 KiB) Viewed 635 times
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48GX
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Re: macOS app Retro Dither creates EXCELLENT BMP files

Post by 48GX »

Certain photos are better for this conversion. Cartoons usually do the best.
Attachments
einstein-pencil-drawing.bmp
einstein-pencil-drawing.bmp (12.25 KiB) Viewed 635 times
anime.bmp
anime.bmp (12.25 KiB) Viewed 635 times
pencil-drawing.bmp
pencil-drawing.bmp (12.25 KiB) Viewed 635 times
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48GX
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Re: macOS app Retro Dither creates EXCELLENT BMP files

Post by 48GX »

One from Oblivion and two inspired by The Hunger Games.
Attachments
hunger-game-salute.bmp
hunger-game-salute.bmp (12.25 KiB) Viewed 512 times
oblivion-drone-166.bmp
oblivion-drone-166.bmp (12.25 KiB) Viewed 620 times
mocking-jay.bmp
mocking-jay.bmp (12.25 KiB) Viewed 620 times
Last edited by 48GX on Wed Apr 20, 2022 12:10 am, edited 1 time in total.
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48GX
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Re: macOS app Retro Dither creates EXCELLENT BMP files

Post by 48GX »

Three more that I like.
Attachments
Alien.bmp
Alien.bmp (12.25 KiB) Viewed 586 times
bomb.bmp
bomb.bmp (12.25 KiB) Viewed 586 times
jet-engine.bmp
jet-engine.bmp (12.25 KiB) Viewed 586 times
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Joe Horn
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Re: macOS app Retro Dither creates EXCELLENT BMP files

Post by Joe Horn »

48GX wrote:
Mon Apr 18, 2022 7:48 pm
One from Oblivion and two inspired by The Hunger Games.
"Hunger-Games.bmp" (the three-finger salute) doesn't load on the calculator, perhaps because it's only 225 pixels high instead of the required 240.

The others look spectacular on the calculator! Awesome work!
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