# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1444162972 -7200
# Node ID 6adea19bfcc290ccdfeed2d4a5c8182b31ab0201
# Parent  1036d8b98d851872a7c994c9b50e20621a36054f
Added options for verifying the number of colours per row, half-resolution
previews, not producing an output image.
Fixed EXIF object usage (which used a nasty global variable).
Simplified the get_colours function signature.

diff -r 1036d8b98d85 -r 6adea19bfcc2 optimiser.py
--- a/optimiser.py	Tue Oct 06 17:33:36 2015 +0200
+++ b/optimiser.py	Tue Oct 06 22:22:52 2015 +0200
@@ -116,7 +116,8 @@
 def amplify_value(x, exp):
     return int(pow(x / 255.0, exp) * 255.0)
 
-def get_colours(im, width, y):
+def get_colours(im, y):
+    width, height = im.size
     c = {}
     for x in range(0, width):
         rgb = im.getpixel((x, y))
@@ -151,8 +152,8 @@
             im.putpixel((x, y), get_value(rgb))
     im.save("rgb%02d%02d%02d.png" % rgb)
 
-def rotate_and_scale(im, width, height, rotate):
-    if rotate or x and x["Image Orientation"].values == [6L]:
+def rotate_and_scale(exif, im, width, height, rotate):
+    if rotate or exif and exif["Image Orientation"].values == [6L]:
         im = im.rotate(270)
 
     w, h = im.size
@@ -163,6 +164,16 @@
 
     return im.resize((width, height))
 
+def count_colours(im, colours):
+    width, height = im.size
+    for y in range(0, height):
+        l = set()
+        for x in range(0, width):
+            l.add(im.getpixel((x, y)))
+        if len(l) > colours:
+            return (y, l)
+    return None
+
 if __name__ == "__main__":
     if "--test" in sys.argv:
         test()
@@ -178,57 +189,78 @@
     basename, ext = splitext(output_filename)
     preview_filename = "".join([basename + "_preview", ext])
 
-    rotate = "-r" in sys.argv[3:]
-    saturate = sys.argv[3:].count("-s")
-    desaturate = sys.argv[3:].count("-d")
-    darken = sys.argv[3:].count("-D")
-    brighten = sys.argv[3:].count("-B")
-    preview = "-p" in sys.argv[3:]
-    square = "-2" in sys.argv[3:] and square or (lambda x: x)
+    options = sys.argv[3:]
 
-    x = EXIF.process_file(open(input_filename))
-    im = PIL.Image.open(input_filename).convert("RGB")
-    im = rotate_and_scale(im, width, height, rotate)
+    rotate = "-r" in options
+    saturate = options.count("-s")
+    desaturate = options.count("-d")
+    darken = options.count("-D")
+    brighten = options.count("-B")
+    square = "-2" in options and square or (lambda x: x)
+    preview = "-p" in options
+    half_resolution_preview = "-h" in options
+    verify = "-v" in options
+    no_normal_output = "-n" in options
+    make_image = not no_normal_output
 
-    width, height = im.size
+    if make_image or preview:
+        exif = EXIF.process_file(open(input_filename))
+        im = PIL.Image.open(input_filename).convert("RGB")
+        im = rotate_and_scale(exif, im, width, height, rotate)
+
+        width, height = im.size
 
-    if saturate or desaturate or darken or brighten:
-        for y in range(0, height):
-            for x in range(0, width):
-                if saturate or desaturate:
-                    rgb = im.getpixel((x, y))
-                    rgb = saturate_rgb(rgb, saturate and math.pow(0.5, saturate) or math.pow(2, desaturate))
-                    im.putpixel((x, y), rgb)
+        if saturate or desaturate or darken or brighten:
+            for y in range(0, height):
+                for x in range(0, width):
+                    if saturate or desaturate:
+                        rgb = im.getpixel((x, y))
+                        rgb = saturate_rgb(rgb, saturate and math.pow(0.5, saturate) or math.pow(2, desaturate))
+                        im.putpixel((x, y), rgb)
 
-                if darken or brighten:
-                    rgb = im.getpixel((x, y))
-                    rgb = amplify_rgb(rgb, brighten and math.pow(0.5, brighten) or math.pow(2, darken))
-                    im.putpixel((x, y), rgb)
+                    if darken or brighten:
+                        rgb = im.getpixel((x, y))
+                        rgb = amplify_rgb(rgb, brighten and math.pow(0.5, brighten) or math.pow(2, darken))
+                        im.putpixel((x, y), rgb)
 
     if preview:
         imp = im.copy()
+        step = half_resolution_preview and 2 or 1
         for y in range(0, height):
-            for x in range(0, width):
+            for x in range(0, width, step):
                 rgb = imp.getpixel((x, y))
                 value = get_value(rgb)
                 imp.putpixel((x, y), value)
+                if half_resolution_preview:
+                    imp.putpixel((x+1, y), value)
+
         imp.save(preview_filename)
 
-    for y in range(0, height):
-        c = get_colours(im, width, y)
-        most = [value for n, value in c[:4]]
-        least = [value for n, value in c[4:]]
+    if make_image:
+        for y in range(0, height):
+            c = get_colours(im, y)
+            most = [value for n, value in c[:4]]
+            least = [value for n, value in c[4:]]
+
+            for x in range(0, width):
+                rgb = im.getpixel((x, y))
+                value = get_value(rgb, most)
+                im.putpixel((x, y), value)
 
-        for x in range(0, width):
-            rgb = im.getpixel((x, y))
-            value = get_value(rgb, most)
-            im.putpixel((x, y), value)
+                if y < height - 1:
+                    rgbn = im.getpixel((x, y+1))
+                    rgbn = tuple(map(lambda i: clip(i[0] + i[1] - i[2]), zip(rgbn, rgb, value)))
+                    im.putpixel((x, y+1), rgbn)
+
+        im.save(output_filename)
 
-            if y < height - 1:
-                rgbn = im.getpixel((x, y+1))
-                rgbn = tuple(map(lambda i: clip(i[0] + i[1] - i[2]), zip(rgbn, rgb, value)))
-                im.putpixel((x, y+1), rgbn)
+    if verify:
+        if no_normal_output:
+            im = PIL.Image.open(output_filename).convert("RGB")
 
-    im.save(output_filename)
+        result = count_colours(im, 4)
+        if result is not None:
+            y, colours = result
+            print "Row %d has the following colours: %s" % (y, "; ".join([repr(c) for c in colours]))
 
 # vim: tabstop=4 expandtab shiftwidth=4