i&m: add operations

1 files changed, 33 insertions, 0 deletions

diff --git a/Year_2/IandM/histogram/histogram.pde b/Year_2/IandM/histogram/histogram.pde
new file mode 100644
index 0000000..58f365a
--- /dev/null
+++ b/Year_2/IandM/histogram/histogram.pde
@@ -0,0 +1,33 @@
+void setup() {
+  size(256, 256);
+  PImage img = loadImage("lena.png");
+  img.resize(256, 256);
+  img.filter(GRAY);
+
+  image(img, 0, 0);
+  float[] hist = histogram(img);
+  for(int i = 0; i < 256; ++i) {
+    println(i, hist[i]);
+  }
+}
+
+float[] histogram(PImage I) {
+  float[] h = new float[256];
+  for (int i = 0; i< 256; ++i) { 
+    h[i] = 0;
+  }
+  
+  I.loadPixels();
+  
+  for(int i = 0; i < I.pixels.length; ++i) {
+    h[int(red(I.pixels[i]))]++;
+  }
+  
+  for(int i = 0; i < 256; ++i) {
+    h[i] = h[i] / I.pixels.length;
+  }
+  
+  I.updatePixels();
+
+  return h;
+}