Data commit

Task/Grayscale-image/OCaml/grayscale-image-1.ocaml

@@ -0,0 +1,20 @@
+let to_grayscale ~img:(_, r_channel, g_channel, b_channel) =
+  let width = Bigarray.Array2.dim1 r_channel
+  and height = Bigarray.Array2.dim2 r_channel in
+
+  let gray_channel =
+    let kind = Bigarray.int8_unsigned
+    and layout = Bigarray.c_layout
+    in
+    (Bigarray.Array2.create kind layout width height)
+  in
+  for y = 0 to pred height do
+    for x = 0 to pred width do
+      let r = r_channel.{x,y}
+      and g = g_channel.{x,y}
+      and b = b_channel.{x,y} in
+      let v = (2_126 * r +  7_152 * g + 722 * b) / 10_000 in
+      gray_channel.{x,y} <- v;
+    done;
+  done;
+  (gray_channel)

Task/Grayscale-image/OCaml/grayscale-image-2.ocaml

@@ -0,0 +1,20 @@
+let to_color ~img:gray_channel =
+  let width = Bigarray.Array2.dim1 gray_channel
+  and height = Bigarray.Array2.dim2 gray_channel in
+  let all_channels =
+    let kind = Bigarray.int8_unsigned
+    and layout = Bigarray.c_layout
+    in
+    Bigarray.Array3.create kind layout 3 width height
+  in
+  let r_channel = Bigarray.Array3.slice_left_2 all_channels 0
+  and g_channel = Bigarray.Array3.slice_left_2 all_channels 1
+  and b_channel = Bigarray.Array3.slice_left_2 all_channels 2
+  in
+  Bigarray.Array2.blit gray_channel r_channel;
+  Bigarray.Array2.blit gray_channel g_channel;
+  Bigarray.Array2.blit gray_channel b_channel;
+  (all_channels,
+   r_channel,
+   g_channel,
+   b_channel)

Task/Grayscale-image/OCaml/grayscale-image-3.ocaml

@@ -0,0 +1,5 @@
+let gray_get_pixel_unsafe (gray_channel) =
+  (fun x y -> gray_channel.{x,y})
+
+let gray_put_pixel_unsafe (gray_channel) v =
+  (fun x y -> gray_channel.{x,y} <- v)