From 899ffe8e9b9cda8802e6795337eafbd7fcb534dc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andr=C3=A1s=20Veres-Szentkir=C3=A1lyi?= <vsza@vsza.hu>
Date: Mon, 1 Jul 2013 23:24:26 +0200
Subject: [PATCH] cache pixel tuple length

---
 pysstv/grayscale.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/pysstv/grayscale.py b/pysstv/grayscale.py
index d793e24..7377f74 100644
--- a/pysstv/grayscale.py
+++ b/pysstv/grayscale.py
@@ -16,9 +16,10 @@ class GrayscaleSSTV(SSTV):
     def encode_line(self, line):
         msec_pixel = self.SCAN / self.WIDTH
         image = self.image.load()
+        pixlen = len(image[0, line])
         for col in xrange(self.WIDTH):
             pixel = image[col, line]
-            freq_pixel = byte_to_freq(sum(pixel) / len(pixel))
+            freq_pixel = byte_to_freq(sum(pixel) / pixlen)
             yield freq_pixel, msec_pixel