From 5b3c21a4d42b024edb4e28ef5c8d35262fed7499 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Johannes=20Sch=C3=B6nberger?= Date: Fri, 22 Nov 2013 12:33:21 +0100 Subject: [PATCH] Add test for neggative gamma parameter --- skimage/exposure/exposure.py | 2 +- skimage/exposure/tests/test_exposure.py | 5 +++++ 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/skimage/exposure/exposure.py b/skimage/exposure/exposure.py index f703f846..31d9a57f 100644 --- a/skimage/exposure/exposure.py +++ b/skimage/exposure/exposure.py @@ -263,7 +263,7 @@ def adjust_gamma(image, gamma=1, gain=1): dtype = image.dtype.type if gamma < 0: - return "Gamma should be a non-negative real number" + raise ValueError("Gamma should be a non-negative real number.") scale = float(dtype_limits(image, True)[1] - dtype_limits(image, True)[0]) diff --git a/skimage/exposure/tests/test_exposure.py b/skimage/exposure/tests/test_exposure.py index f952d158..e6610874 100644 --- a/skimage/exposure/tests/test_exposure.py +++ b/skimage/exposure/tests/test_exposure.py @@ -230,6 +230,11 @@ def test_adjust_gamma_greater_one(): assert_array_equal(result, expected) +def test_adjust_gamma_neggative(): + image = np.arange(0, 255, 4, np.uint8).reshape(8,8) + assert_raises(ValueError, exposure.adjust_gamma, image, -1) + + # Test Logarithmic Correction # ===========================