[Coco] Sockmaster HiColor and Rascan IMG file format
Joel Ewy
jcewy at swbell.net
Sun Jan 7 21:46:41 EST 2007
Ok, just for [fun?] I dug up the .GIFs I made from the DS-69 images and
put them in a gallery on coco3.com:
http://www.coco3.com/gallery/v/User+Albums/JOELAV_DELPHI_COM/
See what a CoCo could do in 1994 (with a little help from a good quality
camcorder and a color splitter.)
JCE
Joel Ewy wrote:
> John Kowalski wrote:
>
>> At 11:40 PM 06/01/2007 -0600, JCE wrote:
>>
>>
>>> I've had a lot of fun playing with Sockmaster's HiColor program, using
>>> BMP files I've scaled down and converted from JPEGs using NETPBM. But
>>> the program can ostensibly display significantly more than 256 colors.
>>> I'd like to see if I can tell the difference between a 12-bit source
>>> image and an 8-bit source image. Problem is I don't have any good .IMG
>>> files to test it out with. Ideally, I'd like to be able to convert
>>> JPEGs into 4096 color .IMG files myself.
>>>
>>>
>> I don't know of any converters and it's been a while since I looked into
>> HiColor, but I seem to recall the "4096" color IMG files may not actually
>> stictly be 4096 colors. The three (R, G and B) pages of the IMG data may
>> have been encoded as 640x200 4-shade dithered images - the dithering being
>> used to increase the visible shades. Mathematically it may have only worked
>> out to be the equivalent of 512 colors.? I may be wrong, that's just my
>> recollection.
>>
>>
> I've seen some .IMG pictures that were actually made on the DS-69 rather
> than the Rascan. These were done in the high-res (4 gray) mode and
> dithered, so they certainly aren't anywhere near 4096 "real" colors.
> They look awful. But it suggests that at one time, somebody had a
> program to make .IMG files from sources other than the Rascan. I
> checked last night, and view 4.4 can't do it. But the Rascan pictures
> I've seen, such as the one in the Rainbow review, looked really good,
> and I'm sure they used 16 gray shades for each color plane.
>
> I also remember making my own real 12-bit images with my DS-69B. I did
> them in the 4-bit per pixel mode. When I tried using a b/w video camera
> and colored celophane filters the results were pretty bad. But I did
> get good results when a friend brought over his camcorder with a digital
> freeze frame, and the color splitter for his Amiga DigiView. With that
> we could capture a still image and individually digitize the red, green,
> and blue components on the CoCo. Then I cooked up a simple C program in
> OS-9 that would read in the three .PIX files, rotate them on the fly,
> and save them all out as a 15-bit Targa file (easy to implement) with
> the LSB unused. (This is pix2tga on rtsi) I then used a DOS utility on
> the PC to quantize the colors down to 256 and convert the Targa file
> into a .GIF which I could view on the PC or the Amiga. (This was
> pre-MM/1, or at least before I got one.) The results of that process
> were very good, though they were rather labor intensive, requiring a lot
> of equipment and moving fairly large data files by floppy disk or Zmodem
> from RS-DOS to OS-9 to MS-DOS to AmigaDOS, et cetera.
>
>>> Of course, it would also be cool if HiColor could read in some other
>>> file formats. Hey Sock, any chance you'd let the source code out of the
>>> bag? :)
>>>
>>> JCE
>>>
>>>
>> You know.. I may as well just post it up on my web page. It would be cool
>> if the code got upgraded/enhanced, or used in other projects - like HiColor
>> title pages for new games or something!
>>
>>
> Cool! I can even imagine a few kinds of games that don't require much
> processing during play that might even include small HiColor images
> during play. A text adventure with graphics comes to mind.
>
>> I'm going to look into finding where I put it and put it on the web in the
>> next day or two. It might not be the prettiest code to look at, or even
>> easy to follow..
>>
>>
> Nobody will make fun of you, I promise!
>
>> John Kowalski (Sock Master)
>> http://www.axess.com/twilight/sock/
>>
>>
>
>
>
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