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primitivefunction

My latest obsession - Dynamic Hi-Res!

by primitivefunction Tue Jun 05, 2018 10:23 am

So back in the late 80s and possibly into the 90s, I remember seeing ads from Newtek like this on the back of many Amiga mags:
NewTek_ad.jpg
NewTek advertisement circa '89

I always found those images super impressive and was intrigued by this so-called Dynamic HiRes display mode. It’s only recently that I discovered how it’s actually achieved - essentially it utilises the copper to swap to a new 16 colour palette on every raster line. Of course many games BITD took advantage of similar tricks like this to display over 100 colours on the screen at once. Dynamic HiRes took it even further and offered thousands of on-screen colours in up to 768 x 480 hi-res overscan without the fringing artefacts of HAM mode - and this was all possible on an OCS Amiga! Admittedly it needed the whole system to itself to render the screen in this mode.

So my question to anyone with knowledge on this subject: how does one convert images into Dynamic HiRes? Is it even possible? I assume that if you had the Digi-View bundle you could save out as DHR, and Newtek released a stand-alone viewer called Dynashow that could display these images. However the only images that I’ve found so far are the ones Newtek created themselves. AFAIK none of the regular paint programs like DPaint supported this mode. Perhaps ADPro did?

I suppose my interest in all of this is purely just for fun of it - seeing how far that original 1985 chipset can be pushed. Eventually I would love to take some true colour 24 bit artwork and see how nice I can get it looking on original Amiga hardware using this mode.

In the meantime, I will continue my research and report back any findings!
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primitivefunction

Re: My latest obsession - Dynamic Hi-Res!

by primitivefunction Tue Jun 05, 2018 10:26 am

Not Dynamic HiRes, but this video gives a good visual explanation on how to achieve high colour counts using the copper - https://www.youtube.com/watch?v=2Lokbjq4-PQ

Apparently there is another mode called SHAM (Sliced HAM) that is very similar to Dynamic Hires. I believe it pre-dates Newtek’s version.
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intric8
Seattle, WA, USA

Re: My latest obsession - Dynamic Hi-Res!

by intric8 Tue Jun 05, 2018 10:31 am

I think - I'll have to double check - but I think you're looking for Art Department Pro.

it utilises the copper to swap to a new 16 colour palette on every raster line.
I think that's what they called "Sliced HAM" back int he day.

Art Dept Pro supports sliced HAM as well as some of NewTek's screen modes.

Speaking of NewTek and converting images, I have the whole setup - I've just not put it together. Something I wanted to do later in the summer. I even have the monochrome Panasonic camera. The only thing I lack to make things perfect is the stand to hold the camera, and the "DigiDroid" which automatically turned the 4 color thingy for you while it took the 4 separate scans. I can go old-school and just spin it with my hand, of course. That's how most folks did it.
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primitivefunction

Re: My latest obsession - Dynamic Hi-Res!

by primitivefunction Tue Jun 05, 2018 10:43 am

Thanks intric8. Yes, it looks like I will have to find a copy of ADPro as it seems to support a myriad of formats - just wasn't sure if DHR was one of them - cheers!

Yeah, I think the Guru Meditation guys might have done a video on the DigiView / Digidroid set-up. Really fascinating stuff. If you end up getting it set up please share with us your results. :)
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intric8
Seattle, WA, USA

Re: My latest obsession - Dynamic Hi-Res!

by intric8 Tue Jun 05, 2018 10:45 am

Oh, I will for sure. Cool.

I could rip an ADF of ADPro if you need any help.
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primitivefunction

Re: My latest obsession - Dynamic Hi-Res!

by primitivefunction Tue Jun 05, 2018 10:47 am

That would be absolutely fantastic. Thank you so much!
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A10001986

Re: My latest obsession - Dynamic Hi-Res!

by A10001986 Tue Jun 05, 2018 10:05 pm

I don't think ADPro supported this. I also don't know any kind of standardized file format for such a "mode".

A "conversion" could only be done by analyzing each scan line and create a palette, perhaps also to using some dithering if necessary (although that would have to be a very smart algorithm in order to avoid artifacts).
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primitivefunction

Re: My latest obsession - Dynamic Hi-Res!

by primitivefunction Wed Jun 06, 2018 1:07 am

Yes, it would require a reasonably smart algorithm and I can actually see where different algorithms would work better for different types of images. Ideally you would have an output module with a lot of control fine-tuning - I’m thinking of Photoshop’s export to GIF tool where you have control over dithering schemes etc.
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intric8
Seattle, WA, USA

Re: My latest obsession - Dynamic Hi-Res!

by intric8 Wed Jun 06, 2018 8:00 am

Ideally you would have an output module with a lot of control fine-tuning
AD Pro absolutely provides this. Although, in WB 1.3 it's more sliders/numbers and you don't know the result until after you move things around then go look. In 2.0, they do provide the ability to see and customize the palettes.

Here's a nice advertisement for it.
About half-way through they show how they take a 24 bit-plane image and convert it down to 256 colors, and then add dithering (or not).

It's a lot like Photoshop without the painting features. Tons of import/export options as well as operators like scaling, blurring, cropping, adding text/animation, etc. I'll shoot you this tonight so you can play around with it.

It's pretty awesome.

Here's a manual you can dig through to see what you might want to try later this week. It's a very powerful program.

Page 149:
AD Pro will read A-HAM images in the same file format (as registered with
CATS, Commodore Applications and Technical Support) used by NewTek's
Dynamic HAM image files.


That being said, further down the page they mention hot it isn't fully supported, but can be read. Anyway, have fun experimenting and let us see what you come up with!
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intric8
Seattle, WA, USA

Re: My latest obsession - Dynamic Hi-Res!

by intric8 Wed Jun 06, 2018 8:37 pm

OK I've been able to get a little more information for you. My version (that I'm using) is Ad Pro 2. This came out in 1990, and it had a patch disk in 1992 I think. In any case, it's 4 total disks, so it'll take me another day before I can get you some software.

I also have version 2.5, which I believe is AGA IIRC and was the final version ASDG Inc. made before they were re-branded then sold to Avid.

In any case, I need a little more time to create ADFs, which is a slow process. But I did fire up the program and it has color controls that include HAM and HAM8. I believe that's more from the viewing/importing side of things, not the exporting necessarily. But I need to educate myself around those capabilities further in the future. I shot a really quick (unlisted) video here to show what I'm talking about.

However, while looking through some things I may have found another option you may want to consider or also try. It's called PIXmate, and supports a lot of modes, too. Check this out:
IMG_5509.jpg

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