01-20-2021, 10:58 AM
(01-19-2021, 11:54 PM)Winston Wrote: Well, could you give me a list of files that can read 2-channels? (Optional setting up to be BY, GM or RC in the header?)
None I know of... In theory in the JPEG format you could omit one of the Cb or Cr channels, but this doesn't give you complete freedom on what you put in the remaining channel
(01-19-2021, 11:54 PM)Winston Wrote: Also, how is it not possible if you can have 1 for B&W, 3 for RGB, 4 for RGBA, etc. Not the 2-channel like black-and-white-alpha, but would "Stereochrome" be the word for it?
Because it there is very little use for this, and is easily implemented by just ignoring one of the channels. FWIW in games some images formats are "abused" and the Alpha channel is repurposed (reflectivity, direction, or else)
(01-19-2021, 11:54 PM)Winston Wrote: At the same time, I could alter audio channels to have 3 speakers (or more) in a WAV file. By the makers of WAV & AVI, what is the image format, if possible?
Yes but this is images we are taking about. Over the years they produced audio systems with 1/2/3/4/5 speakers (or groups of), but since the dawn of times there are only two kinds of image displays, monochrome and RGB. So, whatever you do, at some point your image must have three channels to be displayed, unless you want to cook up your own display hardware and operating system.
(01-19-2021, 11:54 PM)Winston Wrote: "Or you know how to program and write your own file load/save plugin (all file formats in Gimp except XCF are implemented as plugins...)"
Could you link a free Windows 10 app that can make this sort of plugin?
This is called a "brain" with some programming skills and some standard programming tools (hint: there is a python interpreter in Gimp for Windows and NotePad++ is free). Not every problem in the universe can be solved with a silver bullet "app" (for instance, creating the apps themselves).
(01-19-2021, 11:54 PM)Winston Wrote: Note; I made a 3-channel #YBA colored file that works in my browser app, in the code of the page changes Red to Yellow, Green to Blue, Blue to Alpha. This isn't a website, but a page on my computer that changes the colors. Looking at the picture normally looks pycheodelic, but it works in the page. BUT, how to make a 2-channel picture? (Also, when I make my plugin, would it be possible to code what 2 colors to use? Like, in hex, 00=Black-White(Mono), 01=Yellow-Blue, 02=Red-Cyan, 03=Magenta-Green? And possibly, change a byte to say "Read this color first/last" to make something like Red-Cyan change to Cyan-Red?)
As said above, whether you use Gimp or not, at some point your image must be RGB to be displayed. How you map you two channels to RGB values is completely up to you. Typically I would use a CLUT for this: two channels -> two bytes -> A 16-bit word -> an index into a table with 65536 RGB entries. To change the output you just change the CLUT. And yes, this is like color-indexing, but using 16-bit indices instead of 8-bit ones.