preserve high width/height ratios for covers

utils/resize-cover.py

@@ -8,14 +8,30 @@
 import Image
 import glob
 
-width  = 128
-height = 128
-
 # Process song files
 covers = glob.glob('songs/*/*.jpg')
 for filename in covers:
+
     source = Image.open(filename)
-    if source.size > (128, 128):
+
-        print "resizing : " + filename
+    src_width = source.size[0]
+    src_height = source.size[1]
+    ratio = float(src_height) / float(src_width)
+
+    width  = 128
+    height = 128
+    error  = 0.2 #0: always preserve ratio; 1: always square images 
+
+    #tolerate almost square images
+    if ratio < 1 - error  or ratio > 1 + error:
+        #print "preserve ratio = ", ratio
+        #preserve important ratio
+        if src_width < src_height:
+            height = int(width * ratio)
+        elif src_height < src_width:
+            width = int(height * ratio)
+
+    if src_width > width and src_height > height:
+        print "resize: ", filename, " from ", source.size, " to ", (width, height)
         target = source.resize((width, height), Image.ANTIALIAS)
         target.save(filename)