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fix hamming filter

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This commit is contained in:
Alexander 2017-05-29 14:28:55 +03:00
parent 98de727575
commit ad883961ac
2 changed files with 7 additions and 7 deletions
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12
Tests/test_image_resample.py
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@ -158,14 +158,12 @@ class TestImagingCoreResampleAccuracy(PillowTestCase):
def test_enlarge_hamming(self): def test_enlarge_hamming(self):
for mode in ['RGBX', 'RGB', 'La', 'L']: for mode in ['RGBX', 'RGB', 'La', 'L']:
case = self.make_case(mode, (4, 4), 0xe1) case = self.make_case(mode, (2, 2), 0xe1)
case = case.resize((8, 8), Image.HAMMING) case = case.resize((4, 4), Image.HAMMING)
data = ('e1 e1 ea d1' data = ('e1 d2'
'e1 e1 ea d1' 'd2 c5')
'ea ea f4 d9'
'd1 d1 d9 c4')
for channel in case.split(): for channel in case.split():
self.check_case(channel, self.make_sample(data, (8, 8))) self.check_case(channel, self.make_sample(data, (4, 4)))
def test_enlarge_bicubic(self): def test_enlarge_bicubic(self):
for mode in ['RGBX', 'RGB', 'La', 'L']: for mode in ['RGBX', 'RGB', 'La', 'L']:

2
libImaging/Resample.c
View File

@ -32,6 +32,8 @@ static inline double hamming_filter(double x)
x = -x; x = -x;
if (x == 0.0) if (x == 0.0)
return 1.0; return 1.0;
if (x >= 1.0)
return 0.0;
x = x * M_PI; x = x * M_PI;
return sin(x) / x * (0.54f + 0.46f * cos(x)); return sin(x) / x * (0.54f + 0.46f * cos(x));
} }