langs a-z

Task/Image-convolution/OCaml/image-convolution-1.ocaml

@@ -0,0 +1,55 @@
+let get_rgb img x y =
+  let _, r_channel,_,_ = img in
+  let width = Bigarray.Array2.dim1 r_channel
+  and height = Bigarray.Array2.dim2 r_channel in
+  if (x < 0) || (x >= width) then (0,0,0) else
+  if (y < 0) || (y >= height) then (0,0,0) else  (* feed borders with black *)
+  get_pixel img x y
+
+
+let convolve_get_value img kernel divisor offset = fun x y ->
+  let sum_r = ref 0.0
+  and sum_g = ref 0.0
+  and sum_b = ref 0.0 in
+
+  for i = -1 to 1 do
+    for j = -1 to 1 do
+      let r, g, b = get_rgb img (x+i) (y+j) in
+      sum_r := !sum_r +. kernel.(j+1).(i+1) *. (float r);
+      sum_g := !sum_g +. kernel.(j+1).(i+1) *. (float g);
+      sum_b := !sum_b +. kernel.(j+1).(i+1) *. (float b);
+    done;
+  done;
+  ( !sum_r /. divisor +. offset,
+    !sum_g /. divisor +. offset,
+    !sum_b /. divisor +. offset )
+
+
+let color_to_int (r,g,b) =
+  (truncate r,
+   truncate g,
+   truncate b)
+
+let bounded (r,g,b) =
+  ((max 0 (min r 255)),
+   (max 0 (min g 255)),
+   (max 0 (min b 255)))
+
+
+let convolve_value ~img ~kernel ~divisor ~offset =
+  let _, r_channel,_,_ = img in
+  let width = Bigarray.Array2.dim1 r_channel
+  and height = Bigarray.Array2.dim2 r_channel in
+
+  let res = new_img ~width ~height in
+
+  let conv = convolve_get_value img kernel divisor offset in
+
+  for y = 0 to pred height do
+    for x = 0 to pred width do
+      let color = conv x y in
+      let color = color_to_int color in
+      put_pixel res (bounded color) x y;
+    done;
+  done;
+  (res)

Task/Image-convolution/OCaml/image-convolution-2.ocaml

@@ -0,0 +1,35 @@
+let emboss img =
+  let kernel = [|
+    [| -2.; -1.;  0. |];
+    [| -1.;  1.;  1. |];
+    [|  0.;  1.;  2. |];
+  |] in
+  convolve_value ~img ~kernel ~divisor:1.0 ~offset:0.0;
+;;
+
+let sharpen img =
+  let kernel = [|
+    [| -1.; -1.; -1. |];
+    [| -1.;  9.; -1. |];
+    [| -1.; -1.; -1. |];
+  |] in
+  convolve_value ~img ~kernel ~divisor:1.0 ~offset:0.0;
+;;
+
+let sobel_emboss img =
+  let kernel = [|
+    [| -1.; -2.; -1. |];
+    [|  0.;  0.;  0. |];
+    [|  1.;  2.;  1. |];
+  |] in
+  convolve_value ~img ~kernel ~divisor:1.0 ~offset:0.5;
+;;
+
+let box_blur img =
+  let kernel = [|
+    [|  1.;  1.;  1. |];
+    [|  1.;  1.;  1. |];
+    [|  1.;  1.;  1. |];
+  |] in
+  convolve_value ~img ~kernel ~divisor:9.0 ~offset:0.0;
+;;

Task/Image-convolution/Octave/image-convolution.octave

@@ -0,0 +1,23 @@
+function [r, g, b] = rgbconv2(a, c)
+    r = im2uint8(mat2gray(conv2(a(:,:,1), c)));
+    g = im2uint8(mat2gray(conv2(a(:,:,2), c)));
+    b = im2uint8(mat2gray(conv2(a(:,:,3), c)));
+endfunction
+
+im = jpgread("Lenna100.jpg");
+emboss = [-2, -1,  0;
+	  -1,  1,  1;
+	  0,  1,  2 ];
+sobel = [-1., -2., -1.;
+	 0.,  0.,  0.;
+	 1.,  2.,  1. ];
+sharpen =   [ -1.0, -1.0, -1.0;
+	     -1.0,  9.0, -1.0;
+	     -1.0, -1.0, -1.0 ];
+
+[r, g, b] = rgbconv2(im, emboss);
+jpgwrite("LennaEmboss.jpg", r, g, b, 100);
+[r, g, b] = rgbconv2(im, sobel);
+jpgwrite("LennaSobel.jpg", r, g, b, 100);
+[r, g, b] = rgbconv2(im, sharpen);
+jpgwrite("LennaSharpen.jpg", r, g, b, 100);