Data commit

Task/Grayscale-image/Phix/grayscale-image.phix

@@ -0,0 +1,21 @@
+-- demo\rosetta\Bitmap_Greyscale.exw  (runnable version)
+
+function to_grey(sequence image)
+    integer dimx = length(image),
+            dimy = length(image[1])
+    for x=1 to dimx do
+        for y=1 to dimy do
+            integer pixel = image[x][y]          -- red,green,blue
+            sequence r_g_b  =  sq_and_bits(pixel,{#FF0000,#FF00,#FF})
+            integer {r,g,b} = sq_floor_div(r_g_b,{#010000,#0100,#01})
+            image[x][y] = floor(0.2126*r + 0.7152*g + 0.0722*b)*#010101
+        end for
+    end for
+    return image
+end function
+
+--include ppm.e   -- read_ppm(), write_ppm(), to_grey()  (as distributed, instead of the above)
+
+sequence img = read_ppm("Lena.ppm")
+img = to_grey(img)
+write_ppm("LenaGray.ppm",img)