Converting 8 bit bmp to halftone bmp
Start by reading about "generate"

"Generate" will let you create lots of copies of a module with subtly different parameters. It can be a bit fiddly but it's better than creating a dozen copies of something.

However, that's not what you actually want to do here, because if you create a million copies of something you will run out of space.

What you want is a counter:

reg [31:0] var;
always @(posedge clk) begin
   if (var &lt; limit) var &lt;= var + 1;
   else var &lt;= 0;
end


That roughly corresponds to a 'for' loop which will give you an incrementing value of 'var' on each clock cycle, until it hits the limit at which point it will start again from zero.

You'll find the whole thing easier if you store your pixels in an array (or RAM), and dither one pixel per cycle. Then it will take a million clock cycles to do your dithering, but your circuit will be small.

Remember, in Verilog everything happens in parallel, and everything loops forever.