From: cr88192@gmail.com   
      
   On 10/31/2025 1:21 PM, BGB wrote:   
      
   ...   
      
   >   
   > In a lot of the cases, I was using an 8-bit indexed color or color-cell   
   > mode. For indexed color, one needs to send each image through a palette   
   > conversion (to the OS color palette); or run a color-cell encoder.   
   > Mostly because the display HW used 128K of VRAM.   
   >   
   > And, even if RAM backed, there are bandwidth problems with going bigger;   
   > so higher-resolutions had typically worked to reduce the bits per pixel:   
   >     320x200: 16 bpp   
   >     640x400: 4 bpp (color cell), 8 bpp (uses 256K, sorta works)   
   >     800x600: 2 or 4 bpp color-cell   
   >    1024x768: 1 bpp monochrome, other experiments (*1)   
   >      Or, use the 2 bpp mode, for 192K.   
   >   
   > *1: Bayer Pattern Mode/Logic (where the pattern of pixels also encodes   
   > the color);   
   > One possibility also being to use an indexed color pair for every 8x8,   
   > allowing for a 1.25 bpp color cell mode.   
   >   
      
      
   Expanding on this:   
   Idea 1, original:   
   Each group of 2x2 pixels understood as:   
      G R   
      B G   
   With each pixel alternating color.   
      
   But, slightly better for quality is to operate on blocks of 4x4 pixels,   
   with the pixel bits encoding color indirectly for the whole 4x4 block:   
      G R G B   
      B G R G   
      G R G B   
      B G R G   
   So, if >= 4 G bits are set, G is High.   
   So, if >= 2 R bits are set, R is High.   
   So, if >= 2 B bits are set, B is High.   
   If > 8 bits are set, I is high.   
      
   The non-set pixels usually assuming either 0000 (Black) or 1000 (Dark   
   Grey) depending on I bit. Or, a low intensity version of the main color   
   if over 75% of a given bit are set in a given way (say, for mostly flat   
   color blocks).   
      
   Still kinda sucks, but allows a crude approximation of 16 color graphics   
   at 1 bpp...   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)