Creating offimage

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rprosperi
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Re: Creating offimage

Post by rprosperi » Fri Nov 24, 2017 2:51 pm

Geoff Quickfall wrote:
Fri Nov 24, 2017 3:34 am
now, if i may trouble you, what did you use to convert?
Sorry, I should have stated in my post above, that was using plain old MS Paint - in my case it was Win7, but Paint in Win10 is the same.

Create a new file, use Properties to set the size and bit depth of 1 (B&W) and save settings (e.g. save the empty file), then you can copy am image from wherever and paste it into the new doc and you should see the image you are looking for.
--bob p

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Mark Hardman
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Re: Creating offimage

Post by Mark Hardman » Fri Nov 24, 2017 3:13 pm

Geoff Quickfall wrote:
Fri Nov 24, 2017 3:34 am
ha,

Mark, that is it, thanks.

now, if i may trouble you, what did you use to convert?

cheeers, Geoff :ugeek:
You're welcome. I used an online converter located at http://tool.anides.de/. The user interface is a bit clunky but does the job for us lesser mortals.

1. Crop and resize your image to 400x240 and save as a .PNG using Paint or something similar.
2. Go to http://tool.anides.de/.
3. Click on an empty area of the web page and an open box pops up where you can select your source image.
4. Once your image opens, select the 2 color B/W pallet.
5. Go through the drop down of possible dithering algorithms until you find what works best for your image.
6. The tool allows you to save the image. Unfortunately, it only saves to an ancient (Amiga?) .IFF file format. So saving takes a few extra steps.
7. Right-click on the dithered image and select Save As... (or whatever your browser provides). The image will be saved as a 1-bit .PNG.
8. Load the image in Paint and re-save it as a .BMP.

HTH

Mark Hardman
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DavidM
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Re: Creating offimage

Post by DavidM » Sat Nov 25, 2017 6:14 pm

Geoff -

If you'd prefer to stick with PhotoShop for your offimages, here's some similar steps to convert your original 800x480 image:

1) Image>Image Size
- Change dimensions to 400x240 (resample image will have to be selected)
- Select "Bicubic Sharper" as the resample method (optional, but better for most reductions to keep edges crisp)

2) Image>Mode>Grayscale
- If the prompt appears, allow discarding the color information

3) Image>Mode>Bitmap
- Use the same pixels/inch for output as is set for input
- Method: Diffusion Dither

4) Save the file as BMP

In general, images with more contrast will look better as dithered bitmaps. Subtle tonal changes tend to get lost in translation.

Hope this helps!
- David

Geoff Quickfall
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Re: Creating offimage

Post by Geoff Quickfall » Sat Nov 25, 2017 7:33 pm

Thanks Dave,

My hacking skills have diminished since DOS 1.01.

How unearth would I have figured that out :oops:

I was creating text images correctly but they were boring. Converting searches on google did no good.

Will give your method a try today. Would be nice to have a random sel cation floating through the off screen... :!:

Cheers,

Thanks Mark for the initial work. Maybe my next will be my work ;)

Image

mezoganet
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Re: Creating offimage

Post by mezoganet » Thu Jan 24, 2019 1:27 pm

Mark Hardman wrote:
Fri Nov 24, 2017 3:13 pm

You're welcome. I used an online converter located at http://tool.anides.de/. The user interface is a bit clunky but does the job for us lesser mortals.
...
Mark Hardman
Hi Mark,

A little bit late, but before asking the same question on the forum, I wanted to make sure there was no answer yet.

Your process is ok, a bit long and I have to use my Linux PC emulating Windows 10 (VMware) and it's ok.

If someone could give me the answer using just Linux/Ubuntu, or MacOS it would be great !

Thanks a lot !

Patrick
(proud owner of a DM42 for less than a week)
HP33E, HP34C, HP41C, HP16C, HP28S, HP42S, HP48S, HP12C, HP35S, DM42 and HP3000 @ work during 18 yrs as IT Mgr

grsbanks
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Re: Creating offimage

Post by grsbanks » Thu Jan 24, 2019 1:30 pm

Just use the GIMP.

Make sure your image is the correct size (400x240). Convert first to greyscale and make any necessary contrast adjustments. Then convert to 1-bit bitmap using Floyd-Steinberg dithering and save as a .bmp.
Not SwissMicros staff, just an enthusiast.

mezoganet
Posts: 41
Joined: Tue Jan 22, 2019 12:54 pm
Location: Tours, France

Re: Creating offimage

Post by mezoganet » Thu Jan 24, 2019 1:35 pm

grsbanks wrote:
Thu Jan 24, 2019 1:30 pm
Just use the GIMP.

Make sure your image is the correct size (400x240). Convert first to greyscale and make any necessary contrast adjustments. Then convert to 1-bit bitmap using Floyd-Steinberg dithering and save as a .bmp.
Waohhh :o !

3 minutes and you get an answer, that's really fantastic !

Thanks a lot grsbanks, I will try again with GIMP
HP33E, HP34C, HP41C, HP16C, HP28S, HP42S, HP48S, HP12C, HP35S, DM42 and HP3000 @ work during 18 yrs as IT Mgr

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