Merge pull request #146 from wiredfool/webp_tests

Webp tests

PIL/WebPImagePlugin.py

@@ -23,7 +23,7 @@ def _save(im, fp, filename):
         raise IOError("cannot write mode %s as WEBP" % im.mode)
     quality = im.encoderinfo.get("quality", 80)
     
-    data = _webp.WebPEncodeRGB(im.tostring(), im.size[0], im.size[1], im.size[0] * 3, float(quality))
+    data = _webp.WebPEncodeRGB(im.tobytes(), im.size[0], im.size[1], im.size[0] * 3, float(quality))
     fp.write(data)
 
 Image.register_open("WEBP", WebPImageFile, _accept)

Tests/test_file_webp.py

@@ -0,0 +1,43 @@
+from tester import *
+
+from PIL import Image
+
+def test_read():
+    """ Can we write a webp without error. Does it have the bits we expect?"""
+    
+    file = "Images/lena.webp"
+    im = Image.open(file)
+
+    assert_equal(im.mode, "RGB")
+    assert_equal(im.size, (128, 128))
+    assert_equal(im.format, "WEBP")
+    assert_no_exception(lambda: im.load())
+    assert_no_exception(lambda: im.getdata())
+
+    orig_bytes  = im.tobytes()
+
+    # generated with: dwebp -ppm ../../Images/lena.webp -o lena_webp_bits.ppm
+    target = Image.open('Tests/images/lena_webp_bits.ppm')
+    assert_image_equal(im, target)
+    
+
+def test_write():
+    """ Can we write a webp without error. Does it have the bits we expect?"""
+
+    file = tempfile("temp.webp")
+
+    lena("RGB").save(file)
+
+    im= Image.open(file)
+    im.load()
+
+    assert_equal(im.mode, "RGB")
+    assert_equal(im.size, (128, 128))
+    assert_equal(im.format, "WEBP")
+    assert_no_exception(lambda: im.load())
+    assert_no_exception(lambda: im.getdata())
+
+    # generated with: dwebp -ppm temp.webp -o lena_webp_write.ppm
+    target = Image.open('Tests/images/lena_webp_write.ppm')
+    assert_image_equal(im, target)
+