Progress?

demo.lua

@@ -1,5 +1,17 @@
 local bitmap = require'bitmap' --used to read its content
 
+function int_exa(nb)
+  output = "0123456789abcdef"
+  first_digit = 0
+  while nb > 15 do
+    nb = nb - 16
+    first_digit = first_digit + 1
+  end
+  return output:sub(first_digit + 1, 1)..output:sub(nb + 1, 1)
+end
+
+io.write("from casioplot import set_pixel, show_screen as S, R\n")
+
 do --open image
   local cairo = require'cairo' --used to open the file
   local image = cairo.load_png(arg[1])
@@ -7,4 +19,20 @@ do --open image
   image_bitmap = image:bitmap()
 end
 local getpixel, setpixel = bitmap.pixel_interface(image_bitmap)
-print(image_infos.width, image_infos.height)
+
+pallet = {} --will store colors
+pallet_last = 0
+
+
+for j = 1, image_infos.height, 1 do
+  for i = 1, image_infos.width, 1 do
+    r, g, b = getpixel(i, j)
+    if not pallet[r.." "..g.." "..b] then
+      pallet[r.." "..g.." "..b] = pallet_last
+      pallet_last = pallet_last + 1
+    end
+    io.write(int_exa(pallet[r.." "..g.." "..b]))
+  end
+end
+
+io.write("\nR()")