Merge branch 'master' of http://github.com/BSVino/stb into resample

docs/stb_resample_ideas.txt

@@ -190,3 +190,12 @@ Cubic sampling function for seperable cubic:
    f(x) = 0                               otherwise
    "a" is configurable, try -1/2 (from http://pixinsight.com/forum/index.php?topic=556.0 )
 
+
+
+Wish list:
+   s0, t0, s1, t1 vs scale_x, scale_y, offset_x, offset_y - What's the best interface?
+   Separate wrap modes and filter modes per axis
+   Alpha test coverage respecting resize (FloatImage::alphaTestCoverage and FloatImage::scaleAlphaToCoverage: https://code.google.com/p/nvidia-texture-tools/source/browse/trunk/src/nvimage/FloatImage.cpp)
+   Installable filter kernels
+
+

tests/resample_test.cpp

@@ -0,0 +1,430 @@
+#ifdef _WIN32
+#define STBR_ASSERT(x) \
+	if (!(x)) \
+		__debugbreak();
+#else
+#include <assert.h>
+#define STBR_ASSERT(x) assert(x)
+#endif
+
+#define STB_RESAMPLE_IMPLEMENTATION
+#define STB_RESAMPLE_STATIC
+#include "stb_resample.h"
+
+#define STB_IMAGE_WRITE_IMPLEMENTATION
+#include "stb_image_write.h"
+
+#define STB_IMAGE_IMPLEMENTATION
+#include "stb_image.h"
+
+#ifdef _WIN32
+#include <sys/timeb.h>
+#endif
+
+void test_suite();
+
+int main(int argc, char** argv)
+{
+	unsigned char* input_data;
+	unsigned char* output_data;
+	int w, h;
+	int n;
+	int out_w, out_h, out_stride;
+
+#if 1
+	test_suite();
+	return 0;
+#endif
+
+	if (argc <= 1)
+	{
+		printf("No input image\n");
+		return 1;
+	}
+
+	input_data = stbi_load(argv[1], &w, &h, &n, 0);
+	if (!input_data)
+	{
+		printf("Input image could not be loaded");
+		return 1;
+	}
+
+	out_w = 512;
+	out_h = 512;
+	out_stride = (out_w + 10) * n;
+
+	output_data = (unsigned char*)malloc(out_stride * out_h);
+
+	int in_w = 512;
+	int in_h = 512;
+
+	float s0 = 0.25f;
+	float t0 = 0.25f;
+	float s1 = 0.75f;
+	float t1 = 0.75f;
+
+	size_t memory_required = stbr_calculate_memory(in_w, in_h, out_w, out_h, s0, t0, s1, t1, n, STBR_FILTER_CATMULLROM);
+	void* extra_memory = malloc(memory_required);
+
+	// Cut out the outside 64 pixels all around to test the stride.
+	int border = 64;
+	STBR_ASSERT(in_w + border <= w);
+	STBR_ASSERT(in_h + border <= h);
+
+#ifdef PERF_TEST
+	struct timeb initial_time_millis, final_time_millis;
+
+	long average = 0;
+	for (int j = 0; j < 10; j++)
+	{
+		ftime(&initial_time_millis);
+		for (int i = 0; i < 100; i++)
+			stbr_resize_advanced(input_data + w * border * n + border * n, in_w, in_h, w*n, output_data, out_w, out_h, out_stride, n, STBR_TYPE_UINT8, STBR_FILTER_CATMULLROM, STBR_EDGE_CLAMP, STBR_COLORSPACE_SRGB, extra_memory, memory_required);
+		ftime(&final_time_millis);
+		long lapsed_ms = (long)(final_time_millis.time - initial_time_millis.time) * 1000 + (final_time_millis.millitm - initial_time_millis.millitm);
+		printf("Resample: %dms\n", lapsed_ms);
+
+		average += lapsed_ms;
+	}
+
+	average /= 10;
+
+	printf("Average: %dms\n", average);
+#else
+	stbr_resize_advanced(input_data + w * border * n + border * n, in_w, in_h, w*n, output_data, out_w, out_h, out_stride, s0, t0, s1, t1, n, 0, STBR_TYPE_UINT8, STBR_FILTER_CATMULLROM, STBR_EDGE_CLAMP, STBR_COLORSPACE_SRGB, extra_memory, memory_required);
+#endif
+
+	free(extra_memory);
+	stbi_image_free(input_data);
+
+	stbi_write_png("output.png", out_w, out_h, n, output_data, out_stride);
+
+	free(output_data);
+
+	return 0;
+}
+
+void resize_image(const char* filename, float width_percent, float height_percent, stbr_filter filter, stbr_edge edge, stbr_colorspace colorspace, const char* output_filename)
+{
+	int w, h, n;
+
+	unsigned char* input_data = stbi_load(filename, &w, &h, &n, 0);
+	if (!input_data)
+	{
+		printf("Input image could not be loaded");
+		return;
+	}
+
+	int out_w = (int)(w * width_percent);
+	int out_h = (int)(h * height_percent);
+
+	unsigned char* output_data = (unsigned char*)malloc(out_w * out_h * n);
+
+	size_t memory_required = stbr_calculate_memory(w, h, out_w, out_h, 0, 0, 1, 1, n, filter);
+	void* extra_memory = malloc(memory_required);
+
+	stbr_resize_advanced(input_data, w, h, 0, output_data, out_w, out_h, 0, 0, 0, 1, 1, n, 0, STBR_TYPE_UINT8, filter, edge, colorspace, extra_memory, memory_required);
+
+	free(extra_memory);
+	stbi_image_free(input_data);
+
+	stbi_write_png(output_filename, out_w, out_h, n, output_data, 0);
+
+	free(output_data);
+}
+
+template <typename F, typename T>
+void convert_image(const F* input, T* output, int length)
+{
+	double f = (pow(2.0, 8.0 * sizeof(T)) - 1) / (pow(2.0, 8.0 * sizeof(F)) - 1);
+	for (int i = 0; i < length; i++)
+		output[i] = (T)(((double)input[i]) * f);
+}
+
+template <typename T>
+void test_format(const char* file, float width_percent, float height_percent, stbr_type type, stbr_colorspace colorspace)
+{
+	int w, h, n;
+	unsigned char* input_data = stbi_load(file, &w, &h, &n, 0);
+
+	int new_w = (int)(w * width_percent);
+	int new_h = (int)(h * height_percent);
+
+	T* T_data = (T*)malloc(w * h * n * sizeof(T));
+	convert_image<unsigned char, T>(input_data, T_data, w * h * n);
+
+	T* output_data = (T*)malloc(new_w * new_h * n * sizeof(T));
+
+	size_t required = stbr_calculate_memory(w, h, new_w, new_h, 0, 0, 1, 1, n, STBR_FILTER_CATMULLROM);
+	void* extra_memory = malloc(required);
+	stbr_resize_advanced(T_data, w, h, 0, output_data, new_w, new_h, 0, 0, 0, 1, 1, n, 0, type, STBR_FILTER_CATMULLROM, STBR_EDGE_CLAMP, colorspace, extra_memory, required);
+	free(extra_memory);
+
+	free(T_data);
+	stbi_image_free(input_data);
+
+	unsigned char* char_data = (unsigned char*)malloc(new_w * new_h * n * sizeof(char));
+	convert_image<T, unsigned char>(output_data, char_data, new_w * new_h * n);
+
+	char output[200];
+	sprintf(output, "test-output/type-%d-%d-%d-%d-%s", type, colorspace, new_w, new_h, file);
+	stbi_write_png(output, new_w, new_h, n, char_data, 0);
+
+	free(char_data);
+	free(output_data);
+}
+
+void convert_image_float(const unsigned char* input, float* output, int length)
+{
+	for (int i = 0; i < length; i++)
+		output[i] = ((float)input[i])/255;
+}
+
+void convert_image_float(const float* input, unsigned char* output, int length)
+{
+	for (int i = 0; i < length; i++)
+		output[i] = (unsigned char)(input[i] * 255);
+}
+
+void test_float(const char* file, float width_percent, float height_percent, stbr_type type, stbr_colorspace colorspace)
+{
+	int w, h, n;
+	unsigned char* input_data = stbi_load(file, &w, &h, &n, 0);
+
+	int new_w = (int)(w * width_percent);
+	int new_h = (int)(h * height_percent);
+
+	float* T_data = (float*)malloc(w * h * n * sizeof(float));
+	convert_image_float(input_data, T_data, w * h * n);
+
+	float* output_data = (float*)malloc(new_w * new_h * n * sizeof(float));
+
+	size_t required = stbr_calculate_memory(w, h, new_w, new_h, 0, 0, 1, 1, n, STBR_FILTER_CATMULLROM);
+	void* extra_memory = malloc(required);
+	stbr_resize_advanced(T_data, w, h, 0, output_data, new_w, new_h, 0, 0, 0, 1, 1, n, 0, type, STBR_FILTER_CATMULLROM, STBR_EDGE_CLAMP, colorspace, extra_memory, required);
+	free(extra_memory);
+
+	free(T_data);
+	stbi_image_free(input_data);
+
+	unsigned char* char_data = (unsigned char*)malloc(new_w * new_h * n * sizeof(char));
+	convert_image_float(output_data, char_data, new_w * new_h * n);
+
+	char output[200];
+	sprintf(output, "test-output/type-%d-%d-%d-%d-%s", type, colorspace, new_w, new_h, file);
+	stbi_write_png(output, new_w, new_h, n, char_data, 0);
+
+	free(char_data);
+	free(output_data);
+}
+
+void test_channels(const char* file, float width_percent, float height_percent, int channels)
+{
+	int w, h, n;
+	unsigned char* input_data = stbi_load(file, &w, &h, &n, 0);
+
+	int new_w = (int)(w * width_percent);
+	int new_h = (int)(h * height_percent);
+
+	unsigned char* channels_data = (unsigned char*)malloc(w * h * channels * sizeof(unsigned char));
+
+	for (int i = 0; i < w * h; i++)
+	{
+		int input_position = i * n;
+		int output_position = i * channels;
+
+		for (int c = 0; c < channels; c++)
+			channels_data[output_position + c] = input_data[input_position + stbr__min(c, n)];
+	}
+
+	unsigned char* output_data = (unsigned char*)malloc(new_w * new_h * channels * sizeof(unsigned char));
+
+	stbr_resize_uint8_srgb(channels_data, w, h, output_data, new_w, new_h, channels, STBR_FILTER_CATMULLROM, STBR_EDGE_CLAMP);
+
+	free(channels_data);
+	stbi_image_free(input_data);
+
+	char output[200];
+	sprintf(output, "test-output/channels-%d-%d-%d-%s", channels, new_w, new_h, file);
+	stbi_write_png(output, new_w, new_h, channels, output_data, 0);
+
+	free(output_data);
+}
+
+void test_subpixel(const char* file, float width_percent, float height_percent, float s1, float t1)
+{
+	int w, h, n;
+	unsigned char* input_data = stbi_load(file, &w, &h, &n, 0);
+
+	s1 = ((float)w - 1 + s1)/w;
+	t1 = ((float)h - 1 + t1)/h;
+
+	int new_w = (int)(w * width_percent);
+	int new_h = (int)(h * height_percent);
+
+	unsigned char* output_data = (unsigned char*)malloc(new_w * new_h * n * sizeof(unsigned char));
+
+	size_t tempmem_size = stbr_calculate_memory(w, h, new_w, new_h, 0, 0, s1, t1, n, STBR_FILTER_CATMULLROM);
+	void* tempmem = malloc(tempmem_size);
+
+	stbr_resize_advanced(input_data, w, h, 0, output_data, new_w, new_h, 0, 0, 0, s1, t1, n, 0, STBR_TYPE_UINT8, STBR_FILTER_CATMULLROM, STBR_EDGE_CLAMP, STBR_COLORSPACE_SRGB, tempmem, tempmem_size);
+
+	free(tempmem);
+
+	stbi_image_free(input_data);
+
+	char output[200];
+	sprintf(output, "test-output/subpixel-%d-%d-%f-%f-%s", new_w, new_h, s1, t1, file);
+	stbi_write_png(output, new_w, new_h, n, output_data, 0);
+
+	free(output_data);
+}
+
+void test_premul(const char* file)
+{
+	int w, h, n;
+	unsigned char* input_data = stbi_load(file, &w, &h, &n, 4);
+	n = 4;
+
+	// Set alpha for the top half.
+	for (int x = 0; x < w; x++)
+	{
+		for (int y = 0; y < h / 2; y++)
+			input_data[(y*w + x)*n + 3] = input_data[(y*w + x)*n + 0];
+	}
+
+	stbi_write_png("test-output/premul-original.png", w, h, n, input_data, 0);
+
+	int new_w = (int)(w * .1);
+	int new_h = (int)(h * .1);
+
+	unsigned char* output_data = (unsigned char*)malloc(new_w * new_h * n * sizeof(unsigned char));
+
+	size_t tempmem_size = stbr_calculate_memory(w, h, new_w, new_h, 0, 0, 1, 1, n, STBR_FILTER_CATMULLROM);
+	void* tempmem = malloc(tempmem_size);
+
+	stbr_resize_advanced(input_data, w, h, 0, output_data, new_w, new_h, 0, 0, 0, 1, 1, n, 3, STBR_TYPE_UINT8, STBR_FILTER_CATMULLROM, STBR_EDGE_CLAMP, STBR_COLORSPACE_SRGB, tempmem, tempmem_size);
+
+	char output[200];
+	sprintf(output, "test-output/premul-%s", file);
+	stbi_write_png(output, new_w, new_h, n, output_data, 0);
+
+	stbr_resize_advanced(input_data, w, h, 0, output_data, new_w, new_h, 0, 0, 0, 1, 1, n, 0, STBR_TYPE_UINT8, STBR_FILTER_CATMULLROM, STBR_EDGE_CLAMP, STBR_COLORSPACE_SRGB, tempmem, tempmem_size);
+
+	sprintf(output, "test-output/nopremul-%s", file);
+	stbi_write_png(output, new_w, new_h, n, output_data, 0);
+
+	free(tempmem);
+
+	stbi_image_free(input_data);
+
+	free(output_data);
+}
+
+void test_suite()
+{
+	test_premul("barbara.png");
+
+	for (int i = 0; i < 10; i++)
+		test_subpixel("barbara.png", 0.5f, 0.5f, (float)i / 10, 1);
+
+	for (int i = 0; i < 10; i++)
+		test_subpixel("barbara.png", 0.5f, 0.5f, 1, (float)i / 10);
+
+	for (int i = 0; i < 10; i++)
+		test_subpixel("barbara.png", 2, 2, (float)i / 10, 1);
+
+	for (int i = 0; i < 10; i++)
+		test_subpixel("barbara.png", 2, 2, 1, (float)i / 10);
+
+	// Channels test
+	test_channels("barbara.png", 0.5f, 0.5f, 1);
+	test_channels("barbara.png", 0.5f, 0.5f, 2);
+	test_channels("barbara.png", 0.5f, 0.5f, 3);
+	test_channels("barbara.png", 0.5f, 0.5f, 4);
+
+	test_channels("barbara.png", 2, 2, 1);
+	test_channels("barbara.png", 2, 2, 2);
+	test_channels("barbara.png", 2, 2, 3);
+	test_channels("barbara.png", 2, 2, 4);
+
+	// Edge behavior tests
+	resize_image("hgradient.png", 2, 2, STBR_FILTER_CATMULLROM, STBR_EDGE_CLAMP, STBR_COLORSPACE_LINEAR, "test-output/hgradient-clamp.png");
+	resize_image("hgradient.png", 2, 2, STBR_FILTER_CATMULLROM, STBR_EDGE_WRAP, STBR_COLORSPACE_LINEAR, "test-output/hgradient-wrap.png");
+
+	resize_image("vgradient.png", 2, 2, STBR_FILTER_CATMULLROM, STBR_EDGE_CLAMP, STBR_COLORSPACE_LINEAR, "test-output/vgradient-clamp.png");
+	resize_image("vgradient.png", 2, 2, STBR_FILTER_CATMULLROM, STBR_EDGE_WRAP, STBR_COLORSPACE_LINEAR, "test-output/vgradient-wrap.png");
+
+	resize_image("1px-border.png", 2, 2, STBR_FILTER_CATMULLROM, STBR_EDGE_REFLECT, STBR_COLORSPACE_LINEAR, "test-output/1px-border-reflect.png");
+	resize_image("1px-border.png", 2, 2, STBR_FILTER_CATMULLROM, STBR_EDGE_CLAMP, STBR_COLORSPACE_LINEAR, "test-output/1px-border-clamp.png");
+
+	// sRGB tests
+	resize_image("gamma_colors.jpg", .5f, .5f, STBR_FILTER_CATMULLROM, STBR_EDGE_REFLECT, STBR_COLORSPACE_SRGB, "test-output/gamma_colors.jpg");
+	resize_image("gamma_2.2.jpg", .5f, .5f, STBR_FILTER_CATMULLROM, STBR_EDGE_REFLECT, STBR_COLORSPACE_SRGB, "test-output/gamma_2.2.jpg");
+	resize_image("gamma_dalai_lama_gray.jpg", .5f, .5f, STBR_FILTER_CATMULLROM, STBR_EDGE_REFLECT, STBR_COLORSPACE_SRGB, "test-output/gamma_dalai_lama_gray.jpg");
+
+	// filter tests
+	resize_image("barbara.png", 2, 2, STBR_FILTER_NEAREST, STBR_EDGE_CLAMP, STBR_COLORSPACE_SRGB, "test-output/barbara-upsample-nearest.png");
+	resize_image("barbara.png", 2, 2, STBR_FILTER_BILINEAR, STBR_EDGE_CLAMP, STBR_COLORSPACE_SRGB, "test-output/barbara-upsample-bilinear.png");
+	resize_image("barbara.png", 2, 2, STBR_FILTER_BICUBIC, STBR_EDGE_CLAMP, STBR_COLORSPACE_SRGB, "test-output/barbara-upsample-bicubic.png");
+	resize_image("barbara.png", 2, 2, STBR_FILTER_CATMULLROM, STBR_EDGE_CLAMP, STBR_COLORSPACE_SRGB, "test-output/barbara-upsample-catmullrom.png");
+	resize_image("barbara.png", 2, 2, STBR_FILTER_MITCHELL, STBR_EDGE_CLAMP, STBR_COLORSPACE_SRGB, "test-output/barbara-upsample-mitchell.png");
+
+	resize_image("barbara.png", 0.5f, 0.5f, STBR_FILTER_NEAREST, STBR_EDGE_CLAMP, STBR_COLORSPACE_SRGB, "test-output/barbara-downsample-nearest.png");
+	resize_image("barbara.png", 0.5f, 0.5f, STBR_FILTER_BILINEAR, STBR_EDGE_CLAMP, STBR_COLORSPACE_SRGB, "test-output/barbara-downsample-bilinear.png");
+	resize_image("barbara.png", 0.5f, 0.5f, STBR_FILTER_BICUBIC, STBR_EDGE_CLAMP, STBR_COLORSPACE_SRGB, "test-output/barbara-downsample-bicubic.png");
+	resize_image("barbara.png", 0.5f, 0.5f, STBR_FILTER_CATMULLROM, STBR_EDGE_CLAMP, STBR_COLORSPACE_SRGB, "test-output/barbara-downsample-catmullrom.png");
+	resize_image("barbara.png", 0.5f, 0.5f, STBR_FILTER_MITCHELL, STBR_EDGE_CLAMP, STBR_COLORSPACE_SRGB, "test-output/barbara-downsample-mitchell.png");
+
+	for (int i = 10; i < 100; i++)
+	{
+		char outname[200];
+		sprintf(outname, "test-output/barbara-width-%d.jpg", i);
+		resize_image("barbara.png", (float)i / 100, 1, STBR_FILTER_CATMULLROM, STBR_EDGE_CLAMP, STBR_COLORSPACE_SRGB, outname);
+	}
+
+	for (int i = 110; i < 500; i += 10)
+	{
+		char outname[200];
+		sprintf(outname, "test-output/barbara-width-%d.jpg", i);
+		resize_image("barbara.png", (float)i / 100, 1, STBR_FILTER_CATMULLROM, STBR_EDGE_CLAMP, STBR_COLORSPACE_SRGB, outname);
+	}
+
+	for (int i = 10; i < 100; i++)
+	{
+		char outname[200];
+		sprintf(outname, "test-output/barbara-height-%d.jpg", i);
+		resize_image("barbara.png", 1, (float)i / 100, STBR_FILTER_CATMULLROM, STBR_EDGE_CLAMP, STBR_COLORSPACE_SRGB, outname);
+	}
+
+	for (int i = 110; i < 500; i += 10)
+	{
+		char outname[200];
+		sprintf(outname, "test-output/barbara-height-%d.jpg", i);
+		resize_image("barbara.png", 1, (float)i / 100, STBR_FILTER_CATMULLROM, STBR_EDGE_CLAMP, STBR_COLORSPACE_SRGB, outname);
+	}
+
+	for (int i = 50; i < 200; i += 10)
+	{
+		char outname[200];
+		sprintf(outname, "test-output/barbara-width-height-%d.jpg", i);
+		resize_image("barbara.png", 100 / (float)i, (float)i / 100, STBR_FILTER_CATMULLROM, STBR_EDGE_CLAMP, STBR_COLORSPACE_SRGB, outname);
+	}
+
+	test_format<unsigned short>("barbara.png", 0.5, 2.0, STBR_TYPE_UINT16, STBR_COLORSPACE_SRGB);
+	test_format<unsigned short>("barbara.png", 0.5, 2.0, STBR_TYPE_UINT16, STBR_COLORSPACE_LINEAR);
+	test_format<unsigned short>("barbara.png", 2.0, 0.5, STBR_TYPE_UINT16, STBR_COLORSPACE_SRGB);
+	test_format<unsigned short>("barbara.png", 2.0, 0.5, STBR_TYPE_UINT16, STBR_COLORSPACE_LINEAR);
+
+	test_format<unsigned int>("barbara.png", 0.5, 2.0, STBR_TYPE_UINT32, STBR_COLORSPACE_SRGB);
+	test_format<unsigned int>("barbara.png", 0.5, 2.0, STBR_TYPE_UINT32, STBR_COLORSPACE_LINEAR);
+	test_format<unsigned int>("barbara.png", 2.0, 0.5, STBR_TYPE_UINT32, STBR_COLORSPACE_SRGB);
+	test_format<unsigned int>("barbara.png", 2.0, 0.5, STBR_TYPE_UINT32, STBR_COLORSPACE_LINEAR);
+
+	test_float("barbara.png", 0.5, 2.0, STBR_TYPE_FLOAT, STBR_COLORSPACE_SRGB);
+	test_float("barbara.png", 0.5, 2.0, STBR_TYPE_FLOAT, STBR_COLORSPACE_LINEAR);
+	test_float("barbara.png", 2.0, 0.5, STBR_TYPE_FLOAT, STBR_COLORSPACE_SRGB);
+	test_float("barbara.png", 2.0, 0.5, STBR_TYPE_FLOAT, STBR_COLORSPACE_LINEAR);
+}
+
+

tests/resample_test_c.c

@@ -0,0 +1,11 @@
+#ifdef _WIN32
+#define STBR_ASSERT(x) \
+	if (!(x)) \
+		__debugbreak();
+#endif
+
+#define STB_RESAMPLE_IMPLEMENTATION
+#define STB_RESAMPLE_STATIC
+#include "stb_resample.h"
+
+// Just to make sure it will build properly with a c compiler