Data commit

Task/Grayscale-image/Tcl/grayscale-image.tcl

@@ -0,0 +1,13 @@
+package require Tk
+
+proc grayscale image {
+    set w [image width $image]
+    set h [image height $image]
+    for {set x 0} {$x<$w} {incr x} {
+        for {set y 0} {$y<$h} {incr y} {
+            lassign [$image get $x $y] r g b
+            set l [expr {int(0.2126*$r + 0.7152*$g + 0.0722*$b)}]
+            $image put [format "#%02x%02x%02x" $l $l $l] -to $x $y
+        }
+    }
+}