--- /dev/null
+// Unit tests for UnsharpMaskEffect.
+
+#include <math.h>
+
+#include "test_util.h"
+#include "gtest/gtest.h"
+#include "unsharp_mask_effect.h"
+
+TEST(UnsharpMaskEffectTest, NoAmountDoesNothing) {
+ const int size = 4;
+
+ float data[size * size] = {
+ 0.0, 1.0, 0.0, 1.0,
+ 0.0, 1.0, 1.0, 0.0,
+ 0.0, 0.5, 1.0, 0.5,
+ 0.0, 0.0, 0.0, 0.0,
+ };
+ float out_data[size * size];
+
+ EffectChainTester tester(data, size, size, FORMAT_GRAYSCALE, COLORSPACE_sRGB, GAMMA_LINEAR);
+ Effect *unsharp_mask_effect = tester.get_chain()->add_effect(new UnsharpMaskEffect());
+ ASSERT_TRUE(unsharp_mask_effect->set_float("radius", 2.0f));
+ ASSERT_TRUE(unsharp_mask_effect->set_float("amount", 0.0f));
+ tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_LINEAR);
+
+ expect_equal(data, out_data, size, size);
+}
+
+TEST(UnsharpMaskEffectTest, UnblursGaussianBlur) {
+ const int size = 13;
+ const float sigma = 0.5f;
+
+ float data[size * size], out_data[size * size];
+ float expected_data[] = { // One single dot in the middle.
+ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
+ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
+ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
+ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
+ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
+ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
+ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
+ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
+ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
+ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
+ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
+ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
+ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
+ };
+
+ // Create a Gaussian input. (Note that our blur is not Gaussian.)
+ for (int y = 0; y < size; ++y) {
+ for (int x = 0; x < size; ++x) {
+ float z = hypot(x - 6, y - 6);
+ data[y * size + x] = exp(-z*z / (2.0 * sigma * sigma)) / (2.0 * M_PI * sigma * sigma);
+ }
+ }
+
+ EffectChainTester tester(data, size, size, FORMAT_GRAYSCALE, COLORSPACE_sRGB, GAMMA_LINEAR);
+ Effect *unsharp_mask_effect = tester.get_chain()->add_effect(new UnsharpMaskEffect());
+ ASSERT_TRUE(unsharp_mask_effect->set_float("radius", sigma));
+ tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_LINEAR);
+
+ // Check the center sample separately; it's bound to be the sample with the largest
+ // single error, and we know we can't get it perfect anyway.
+ int center = size / 2;
+ EXPECT_GT(out_data[center * size + center], 0.45f);
+ out_data[center * size + center] = 1.0f;
+
+ // Add some leeway for the rest; unsharp masking is not expected to be extremely good.
+ expect_equal(expected_data, out_data, size, size, 0.1, 0.001);
+}