resize: add spline64 filter

sekrit-twc · Mar 2, 2020 · 6ffe4b1 · 6ffe4b1
1 parent 1ea31d1
commit 6ffe4b1
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Showing 7 changed files with 54 additions and 2 deletions.
diff --git a/src/testapp/table.cpp b/src/testapp/table.cpp
@@ -114,12 +114,13 @@ const zimg::static_string_map<DitherType, 4> g_dither_table{
 	{ "error_diffusion", DitherType::ERROR_DIFFUSION },
 };
 
-const zimg::static_string_map<std::unique_ptr<zimg::resize::Filter>(*)(double, double), 7> g_resize_table{
+const zimg::static_string_map<std::unique_ptr<zimg::resize::Filter>(*)(double, double), 8> g_resize_table{
 	{ "point",    make_filter<zimg::resize::PointFilter> },
 	{ "bilinear", make_filter<zimg::resize::BilinearFilter> },
 	{ "bicubic",  make_bicubic_filter },
 	{ "spline16", make_filter<zimg::resize::Spline16Filter> },
 	{ "spline36", make_filter<zimg::resize::Spline36Filter> },
+	{ "spline64", make_filter<zimg::resize::Spline64Filter> },
 	{ "lanczos",  make_lanczos_filter },
 	{ "unresize", make_null_filter },
 };
diff --git a/src/testapp/table.h b/src/testapp/table.h
@@ -40,6 +40,6 @@ extern const zimg::static_string_map<zimg::colorspace::MatrixCoefficients, 12> g
 extern const zimg::static_string_map<zimg::colorspace::TransferCharacteristics, 12> g_transfer_table;
 extern const zimg::static_string_map<zimg::colorspace::ColorPrimaries, 12> g_primaries_table;
 extern const zimg::static_string_map<zimg::depth::DitherType, 4> g_dither_table;
-extern const zimg::static_string_map<std::unique_ptr<zimg::resize::Filter>(*)(double, double), 7> g_resize_table;
+extern const zimg::static_string_map<std::unique_ptr<zimg::resize::Filter>(*)(double, double), 8> g_resize_table;
 
 #endif // TABLE_H_
diff --git a/src/zimg/api/zimg.cpp b/src/zimg/api/zimg.cpp
@@ -322,6 +322,8 @@ std::unique_ptr<zimg::resize::Filter> translate_resize_filter(zimg_resample_filt
 			return ztd::make_unique<zimg::resize::Spline16Filter>();
 		case ZIMG_RESIZE_SPLINE36:
 			return ztd::make_unique<zimg::resize::Spline36Filter>();
+		case ZIMG_RESIZE_SPLINE64:
+			return ztd::make_unique<zimg::resize::Spline64Filter>();
 		case ZIMG_RESIZE_LANCZOS:
 			param_a = std::isnan(param_a) ? zimg::resize::LanczosFilter::DEFAULT_TAPS : std::max(param_a, 1.0);
 			return ztd::make_unique<zimg::resize::LanczosFilter>(static_cast<unsigned>(param_a));

diff --git a/src/zimg/api/zimg.h b/src/zimg/api/zimg.h
@@ -351,6 +351,7 @@ typedef enum zimg_resample_filter_e {
 	ZIMG_RESIZE_BICUBIC  = 2, /**< Bicubic convolution (separable) filter. */
 	ZIMG_RESIZE_SPLINE16 = 3, /**< "Spline16" filter from AviSynth. */
 	ZIMG_RESIZE_SPLINE36 = 4, /**< "Spline36" filter from AviSynth. */
+	ZIMG_RESIZE_SPLINE64 = 6, /**< "Spline64" filter from AviSynth. */
 	ZIMG_RESIZE_LANCZOS  = 5  /**< Lanczos resampling filter with variable number of taps. */
 } zimg_resample_filter_e;
 

diff --git a/src/zimg/resize/filter.cpp b/src/zimg/resize/filter.cpp
@@ -210,6 +210,29 @@ double Spline36Filter::operator()(double x) const
 }
 
 
+unsigned Spline64Filter::support() const { return 4; }
+
+double Spline64Filter::operator()(double x) const
+{
+	x = std::abs(x);
+
+	if (x < 1.0) {
+		return poly3(x, 1.0,    -3.0 / 2911.0, -6387.0 / 2911.0,  49.0 / 41.0);
+	} else if (x < 2.0) {
+		x -= 1.0;
+		return poly3(x, 0.0, -2328.0 / 2911.0,  4032.0 / 2911.0, -24.0 / 41.0);
+	} else if (x < 3.0) {
+		x -= 2.0;
+		return poly3(x, 0.0,   582.0 / 2911.0, -1008.0 / 2911.0,   6.0 / 41.0);
+	} else if (x < 4.0) {
+		x -= 3.0;
+		return poly3(x, 0.0,   -97.0 / 2911.0,   168.0 / 2911.0,  -1.0 / 41.0);
+	} else {
+		return 0.0;
+	}
+}
+
+
 LanczosFilter::LanczosFilter(unsigned taps) : taps{ taps }
 {
 	if (taps <= 0)

diff --git a/src/zimg/resize/filter.h b/src/zimg/resize/filter.h
@@ -96,6 +96,16 @@ class Spline36Filter : public Filter {
 	double operator()(double x) const override;
 };
 
+/**
+ * Spline64 filter from Avisynth.
+ */
+class Spline64Filter : public Filter {
+public:
+	unsigned support() const override;
+
+	double operator()(double x) const override;
+};
+
 /**
  * Lanczos filter.
  */

diff --git a/test/resize/filter_test.cpp b/test/resize/filter_test.cpp
@@ -80,6 +80,21 @@ TEST(FilterTest, test_spline36)
 	EXPECT_NEAR(0.0197368, f(-2.5), 1e-6);
 }
 
+TEST(FilterTest, test_spline64)
+{
+	zimg::resize::Spline64Filter f;
+	EXPECT_EQ(4U, f.support());
+	check_interpolating(f);
+	EXPECT_NEAR(0.600352, f(0.5), 1e-6);
+	EXPECT_NEAR(0.600352, f(-0.5), 1e-6);
+	EXPECT_NEAR(-0.126760, f(1.5), 1e-6);
+	EXPECT_NEAR(-0.126760, f(-1.5), 1e-6);
+	EXPECT_NEAR(0.0316901, f(2.5), 1e-7);
+	EXPECT_NEAR(0.0316901, f(-2.5), 1e-7);
+	EXPECT_NEAR(-0.00528169, f(3.5), 1e-8);
+	EXPECT_NEAR(-0.00528169, f(-3.5), 1e-8);
+}
+
 TEST(FilterTest, test_lanczos)
 {
 	for (unsigned i = 1; i < 4; ++i) {