#define NO_SDL_GLEXT 1
-#define WIDTH 1280
-#define HEIGHT 720
-
#include <epoxy/gl.h>
#include <SDL2/SDL.h>
return obj;
}
-
-GLuint load_texture(const char *filename, unsigned width, unsigned height)
+GLuint load_texture(const char *filename, unsigned *width_ret, unsigned *height_ret)
{
- FILE *fp = fopen(filename, "rb");
- if (fp == nullptr) {
- perror(filename);
+ SDL_Surface *surf = IMG_Load(filename);
+ if (surf == nullptr) {
+ fprintf(stderr, "IMG_Load(%s): %s\n", filename, IMG_GetError());
exit(1);
}
- unique_ptr<uint8_t[]> pix(new uint8_t[width * height]);
- if (fread(pix.get(), width * height, 1, fp) != 1) {
- fprintf(stderr, "Short read from %s\n", filename);
+
+ // For whatever reason, SDL doesn't support converting to YUV surfaces
+ // nor grayscale, so we'll do it (slowly) ourselves.
+ SDL_Surface *rgb_surf = SDL_ConvertSurfaceFormat(surf, SDL_PIXELFORMAT_RGBA8888, /*flags=*/0);
+ if (rgb_surf == nullptr) {
+ fprintf(stderr, "SDL_ConvertSurfaceFormat(%s): %s\n", filename, SDL_GetError());
exit(1);
}
- fclose(fp);
- // Convert to bottom-left origin.
- for (unsigned y = 0; y < height / 2; ++y) {
+ SDL_FreeSurface(surf);
+
+ unsigned width = rgb_surf->w, height = rgb_surf->h;
+ const uint8_t *sptr = (uint8_t *)rgb_surf->pixels;
+ unique_ptr<uint8_t[]> pix(new uint8_t[width * height]);
+
+ // Extract the Y component, and convert to bottom-left origin.
+ for (unsigned y = 0; y < height; ++y) {
unsigned y2 = height - 1 - y;
- swap_ranges(&pix[y * width], &pix[y * width + width], &pix[y2 * width]);
+ for (unsigned x = 0; x < width; ++x) {
+ uint8_t r = sptr[(y2 * width + x) * 4 + 3];
+ uint8_t g = sptr[(y2 * width + x) * 4 + 2];
+ uint8_t b = sptr[(y2 * width + x) * 4 + 1];
+
+ // Rec. 709.
+ pix[y * width + x] = lrintf(r * 0.2126f + g * 0.7152f + b * 0.0722f);
+ }
}
+ SDL_FreeSurface(rgb_surf);
int levels = 1;
for (int w = width, h = height; w > 1 || h > 1; ) {
glTextureSubImage2D(tex, 0, 0, 0, width, height, GL_RED, GL_UNSIGNED_BYTE, pix.get());
glGenerateTextureMipmap(tex);
+ *width_ret = width;
+ *height_ret = height;
+
return tex;
}
class MotionSearch {
public:
MotionSearch();
- void exec(GLuint tex0_view, GLuint tex1_view, GLuint grad0_tex, GLuint flow_tex, GLuint flow_out_tex, int level_width, int level_height, int width_patches, int height_patches);
+ void exec(GLuint tex0_view, GLuint tex1_view, GLuint grad0_tex, GLuint flow_tex, GLuint flow_out_tex, int level_width, int level_height, int prev_level_width, int prev_level_height, int width_patches, int height_patches);
private:
GLuint motion_vs_obj;
GLuint motion_search_program;
GLuint motion_search_vao;
- GLuint uniform_image_size, uniform_inv_image_size;
+ GLuint uniform_image_size, uniform_inv_image_size, uniform_inv_prev_level_size;
GLuint uniform_image0_tex, uniform_image1_tex, uniform_grad0_tex, uniform_flow_tex;
};
uniform_image_size = glGetUniformLocation(motion_search_program, "image_size");
uniform_inv_image_size = glGetUniformLocation(motion_search_program, "inv_image_size");
+ uniform_inv_prev_level_size = glGetUniformLocation(motion_search_program, "inv_prev_level_size");
uniform_image0_tex = glGetUniformLocation(motion_search_program, "image0_tex");
uniform_image1_tex = glGetUniformLocation(motion_search_program, "image1_tex");
uniform_grad0_tex = glGetUniformLocation(motion_search_program, "grad0_tex");
uniform_flow_tex = glGetUniformLocation(motion_search_program, "flow_tex");
}
-void MotionSearch::exec(GLuint tex0_view, GLuint tex1_view, GLuint grad0_tex, GLuint flow_tex, GLuint flow_out_tex, int level_width, int level_height, int width_patches, int height_patches)
+void MotionSearch::exec(GLuint tex0_view, GLuint tex1_view, GLuint grad0_tex, GLuint flow_tex, GLuint flow_out_tex, int level_width, int level_height, int prev_level_width, int prev_level_height, int width_patches, int height_patches)
{
glUseProgram(motion_search_program);
glProgramUniform2f(motion_search_program, uniform_image_size, level_width, level_height);
glProgramUniform2f(motion_search_program, uniform_inv_image_size, 1.0f / level_width, 1.0f / level_height);
+ glProgramUniform2f(motion_search_program, uniform_inv_prev_level_size, 1.0f / prev_level_width, 1.0f / prev_level_height);
GLuint flow_fbo; // TODO: cleanup
glCreateFramebuffers(1, &flow_fbo);
// I_0 and I_w. The prewarping is what enables us to solve the variational
// flow for du,dv instead of u,v.
//
+// Also calculates the normalized flow, ie. divides by z (this is needed because
+// Densify works by additive blending) and multiplies by the image size.
+//
// See variational_refinement.txt for more information.
class Prewarp {
public:
Prewarp();
- void exec(GLuint tex0_view, GLuint tex1_view, GLuint flow_tex, GLuint I_tex, GLuint I_t_tex, int level_width, int level_height);
+ void exec(GLuint tex0_view, GLuint tex1_view, GLuint flow_tex, GLuint normalized_flow_tex, GLuint I_tex, GLuint I_t_tex, int level_width, int level_height);
private:
GLuint prewarp_vs_obj;
GLuint prewarp_vao;
GLuint uniform_image0_tex, uniform_image1_tex, uniform_flow_tex;
+ GLuint uniform_image_size;
};
Prewarp::Prewarp()
uniform_image0_tex = glGetUniformLocation(prewarp_program, "image0_tex");
uniform_image1_tex = glGetUniformLocation(prewarp_program, "image1_tex");
uniform_flow_tex = glGetUniformLocation(prewarp_program, "flow_tex");
+
+ uniform_image_size = glGetUniformLocation(prewarp_program, "image_size");
}
-void Prewarp::exec(GLuint tex0_view, GLuint tex1_view, GLuint flow_tex, GLuint I_tex, GLuint I_t_tex, int level_width, int level_height)
+void Prewarp::exec(GLuint tex0_view, GLuint tex1_view, GLuint flow_tex, GLuint I_tex, GLuint I_t_tex, GLuint normalized_flow_tex, int level_width, int level_height)
{
glUseProgram(prewarp_program);
bind_sampler(prewarp_program, uniform_image1_tex, 1, tex1_view, linear_sampler);
bind_sampler(prewarp_program, uniform_flow_tex, 2, flow_tex, nearest_sampler);
+ glProgramUniform2f(prewarp_program, uniform_image_size, level_width, level_height);
+
GLuint prewarp_fbo; // TODO: cleanup
glCreateFramebuffers(1, &prewarp_fbo);
- GLenum bufs[] = { GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1 };
- glNamedFramebufferDrawBuffers(prewarp_fbo, 2, bufs);
+ GLenum bufs[] = { GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1, GL_COLOR_ATTACHMENT2 };
+ glNamedFramebufferDrawBuffers(prewarp_fbo, 3, bufs);
glNamedFramebufferTexture(prewarp_fbo, GL_COLOR_ATTACHMENT0, I_tex, 0);
glNamedFramebufferTexture(prewarp_fbo, GL_COLOR_ATTACHMENT1, I_t_tex, 0);
+ glNamedFramebufferTexture(prewarp_fbo, GL_COLOR_ATTACHMENT2, normalized_flow_tex, 0);
glViewport(0, 0, level_width, level_height);
glDisable(GL_BLEND);
glViewport(0, 0, level_width, level_height);
- // Make sure the smoothness on the right and upper borders is zero.
- // We could have done this by making (W-1)xH and Wx(H-1) textures instead
- // (we're sampling smoothness with all-zero border color), but we'd
- // have to adjust the sampling coordinates, which is annoying.
- //
- // FIXME: We shouldn't scissor width for horizontal,
- // and we shouldn't scissor height for vertical
- glScissor(0, 0, level_width - 1, level_height - 1);
- glEnable(GL_SCISSOR_TEST);
-
glDisable(GL_BLEND);
glBindVertexArray(smoothness_vao);
glBindFramebuffer(GL_FRAMEBUFFER, smoothness_fbo);
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
- glDisable(GL_SCISSOR_TEST);
+ // Make sure the smoothness on the right and upper borders is zero.
+ // We could have done this by making (W-1)xH and Wx(H-1) textures instead
+ // (we're sampling smoothness with all-zero border color), but we'd
+ // have to adjust the sampling coordinates, which is annoying.
+ glClearTexSubImage(smoothness_x_tex, 0, level_width - 1, 0, 0, 1, level_height, 1, GL_RED, GL_FLOAT, nullptr);
+ glClearTexSubImage(smoothness_y_tex, 0, 0, level_height - 1, 0, level_width, 1, 1, GL_RED, GL_FLOAT, nullptr);
}
// Set up the equations set (two equations in two unknowns, per pixel).
GLuint equations_vao;
GLuint uniform_I_x_y_tex, uniform_I_t_tex;
- GLuint uniform_diff_flow_tex, uniform_flow_tex;
+ GLuint uniform_diff_flow_tex, uniform_base_flow_tex;
GLuint uniform_beta_0_tex;
GLuint uniform_smoothness_x_tex, uniform_smoothness_y_tex;
-
};
SetupEquations::SetupEquations()
uniform_I_x_y_tex = glGetUniformLocation(equations_program, "I_x_y_tex");
uniform_I_t_tex = glGetUniformLocation(equations_program, "I_t_tex");
uniform_diff_flow_tex = glGetUniformLocation(equations_program, "diff_flow_tex");
- uniform_flow_tex = glGetUniformLocation(equations_program, "flow_tex");
+ uniform_base_flow_tex = glGetUniformLocation(equations_program, "base_flow_tex");
uniform_beta_0_tex = glGetUniformLocation(equations_program, "beta_0_tex");
uniform_smoothness_x_tex = glGetUniformLocation(equations_program, "smoothness_x_tex");
uniform_smoothness_y_tex = glGetUniformLocation(equations_program, "smoothness_y_tex");
}
-void SetupEquations::exec(GLuint I_x_y_tex, GLuint I_t_tex, GLuint diff_flow_tex, GLuint flow_tex, GLuint beta_0_tex, GLuint smoothness_x_tex, GLuint smoothness_y_tex, GLuint equation_tex, int level_width, int level_height)
+void SetupEquations::exec(GLuint I_x_y_tex, GLuint I_t_tex, GLuint diff_flow_tex, GLuint base_flow_tex, GLuint beta_0_tex, GLuint smoothness_x_tex, GLuint smoothness_y_tex, GLuint equation_tex, int level_width, int level_height)
{
glUseProgram(equations_program);
bind_sampler(equations_program, uniform_I_x_y_tex, 0, I_x_y_tex, nearest_sampler);
bind_sampler(equations_program, uniform_I_t_tex, 1, I_t_tex, nearest_sampler);
bind_sampler(equations_program, uniform_diff_flow_tex, 2, diff_flow_tex, nearest_sampler);
- bind_sampler(equations_program, uniform_flow_tex, 3, flow_tex, nearest_sampler);
+ bind_sampler(equations_program, uniform_base_flow_tex, 3, base_flow_tex, nearest_sampler);
bind_sampler(equations_program, uniform_beta_0_tex, 4, beta_0_tex, nearest_sampler);
bind_sampler(equations_program, uniform_smoothness_x_tex, 5, smoothness_x_tex, smoothness_sampler);
bind_sampler(equations_program, uniform_smoothness_y_tex, 6, smoothness_y_tex, smoothness_sampler);
}
// Simply add the differential flow found by the variational refinement to the base flow.
-// The output is in diff_flow_tex; we don't need to make a new texture.
+// The output is in base_flow_tex; we don't need to make a new texture.
class AddBaseFlow {
public:
AddBaseFlow();
GLuint add_flow_program;
GLuint add_flow_vao;
- GLuint uniform_base_flow_tex;
+ GLuint uniform_diff_flow_tex;
};
AddBaseFlow::AddBaseFlow()
glEnableVertexArrayAttrib(add_flow_vao, position_attrib);
glVertexAttribPointer(position_attrib, 2, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(0));
- uniform_base_flow_tex = glGetUniformLocation(add_flow_program, "base_flow_tex");
+ uniform_diff_flow_tex = glGetUniformLocation(add_flow_program, "diff_flow_tex");
}
void AddBaseFlow::exec(GLuint base_flow_tex, GLuint diff_flow_tex, int level_width, int level_height)
{
glUseProgram(add_flow_program);
- bind_sampler(add_flow_program, uniform_base_flow_tex, 0, base_flow_tex, nearest_sampler);
+ bind_sampler(add_flow_program, uniform_diff_flow_tex, 0, diff_flow_tex, nearest_sampler);
GLuint add_flow_fbo; // TODO: cleanup
glCreateFramebuffers(1, &add_flow_fbo);
- glNamedFramebufferTexture(add_flow_fbo, GL_COLOR_ATTACHMENT0, diff_flow_tex, 0);
+ glNamedFramebufferTexture(add_flow_fbo, GL_COLOR_ATTACHMENT0, base_flow_tex, 0);
glViewport(0, 0, level_width, level_height);
glEnable(GL_BLEND);
bool ended = false;
};
-int main(void)
+int main(int argc, char **argv)
{
if (SDL_Init(SDL_INIT_EVERYTHING) == -1) {
fprintf(stderr, "SDL_Init failed: %s\n", SDL_GetError());
assert(context != nullptr);
// Load pictures.
- GLuint tex0 = load_texture("test1499.pgm", WIDTH, HEIGHT);
- GLuint tex1 = load_texture("test1500.pgm", WIDTH, HEIGHT);
+ unsigned width1, height1, width2, height2;
+ GLuint tex0 = load_texture(argc >= 2 ? argv[1] : "test1499.png", &width1, &height1);
+ GLuint tex1 = load_texture(argc >= 3 ? argv[2] : "test1500.png", &width2, &height2);
+
+ if (width1 != width2 || height1 != height2) {
+ fprintf(stderr, "Image dimensions don't match (%dx%d versus %dx%d)\n",
+ width1, height1, width2, height2);
+ exit(1);
+ }
// Make some samplers.
glCreateSamplers(1, &nearest_sampler);
GLuint initial_flow_tex;
glCreateTextures(GL_TEXTURE_2D, 1, &initial_flow_tex);
glTextureStorage2D(initial_flow_tex, 1, GL_RG16F, 1, 1);
+ int prev_level_width = 1, prev_level_height = 1;
GLuint prev_level_flow_tex = initial_flow_tex;
snprintf(timer_name, sizeof(timer_name), "Level %d", level);
ScopedTimer level_timer(timer_name, &total_timer);
- int level_width = WIDTH >> level;
- int level_height = HEIGHT >> level;
+ int level_width = width1 >> level;
+ int level_height = height1 >> level;
float patch_spacing_pixels = patch_size_pixels * (1.0f - patch_overlap_ratio);
int width_patches = 1 + lrintf((level_width - patch_size_pixels) / patch_spacing_pixels);
int height_patches = 1 + lrintf((level_height - patch_size_pixels) / patch_spacing_pixels);
// And draw.
{
ScopedTimer timer("Motion search", &level_timer);
- motion_search.exec(tex0_view, tex1_view, grad0_tex, prev_level_flow_tex, flow_out_tex, level_width, level_height, width_patches, height_patches);
+ motion_search.exec(tex0_view, tex1_view, grad0_tex, prev_level_flow_tex, flow_out_tex, level_width, level_height, prev_level_width, prev_level_height, width_patches, height_patches);
}
// Densification.
GLuint dense_flow_tex;
glCreateTextures(GL_TEXTURE_2D, 1, &dense_flow_tex);
glTextureStorage2D(dense_flow_tex, 1, GL_RGB16F, level_width, level_height);
+ glClearTexImage(dense_flow_tex, 0, GL_RGB, GL_FLOAT, nullptr);
// And draw.
{
// Everything below here in the loop belongs to variational refinement.
ScopedTimer varref_timer("Variational refinement", &level_timer);
- // Prewarping; create I and I_t.
- GLuint I_tex, I_t_tex;
+ // Prewarping; create I and I_t, and a normalized base flow (so we don't
+ // have to normalize it over and over again, and also save some bandwidth).
+ //
+ // During the entire rest of the variational refinement, flow will be measured
+ // in pixels, not 0..1 normalized OpenGL texture coordinates.
+ // This is because variational refinement depends so heavily on derivatives,
+ // which are measured in intensity levels per pixel.
+ GLuint I_tex, I_t_tex, base_flow_tex;
glCreateTextures(GL_TEXTURE_2D, 1, &I_tex);
glCreateTextures(GL_TEXTURE_2D, 1, &I_t_tex);
+ glCreateTextures(GL_TEXTURE_2D, 1, &base_flow_tex);
glTextureStorage2D(I_tex, 1, GL_R16F, level_width, level_height);
glTextureStorage2D(I_t_tex, 1, GL_R16F, level_width, level_height);
+ glTextureStorage2D(base_flow_tex, 1, GL_RG16F, level_width, level_height);
{
ScopedTimer timer("Prewarping", &varref_timer);
- prewarp.exec(tex0_view, tex1_view, dense_flow_tex, I_tex, I_t_tex, level_width, level_height);
+ prewarp.exec(tex0_view, tex1_view, dense_flow_tex, I_tex, I_t_tex, base_flow_tex, level_width, level_height);
}
// Calculate I_x and I_y. We're only calculating first derivatives;
GLuint du_dv_tex;
glCreateTextures(GL_TEXTURE_2D, 1, &du_dv_tex);
glTextureStorage2D(du_dv_tex, 1, GL_RG16F, level_width, level_height);
+ glClearTexImage(du_dv_tex, 0, GL_RG, GL_FLOAT, nullptr);
// And for smoothness.
GLuint smoothness_x_tex, smoothness_y_tex;
// both in x and y direction.
{
ScopedTimer timer("Compute smoothness", &varref_timer);
- compute_smoothness.exec(dense_flow_tex, du_dv_tex, smoothness_x_tex, smoothness_y_tex, level_width, level_height);
+ compute_smoothness.exec(base_flow_tex, du_dv_tex, smoothness_x_tex, smoothness_y_tex, level_width, level_height);
}
// Set up the 2x2 equation system for each pixel.
{
ScopedTimer timer("Set up equations", &varref_timer);
- setup_equations.exec(I_x_y_tex, I_t_tex, du_dv_tex, dense_flow_tex, beta_0_tex, smoothness_x_tex, smoothness_y_tex, equation_tex, level_width, level_height);
+ setup_equations.exec(I_x_y_tex, I_t_tex, du_dv_tex, base_flow_tex, beta_0_tex, smoothness_x_tex, smoothness_y_tex, equation_tex, level_width, level_height);
}
// Run a few SOR (or quasi-SOR, since we're not really Jacobi) iterations.
// Add the differential flow found by the variational refinement to the base flow,
// giving the final flow estimate for this level.
// The output is in diff_flow_tex; we don't need to make a new texture.
+ // You can comment out this part if you wish to test disabling of the variational refinement.
{
ScopedTimer timer("Add differential flow", &varref_timer);
- add_base_flow.exec(dense_flow_tex, du_dv_tex, level_width, level_height);
+ add_base_flow.exec(base_flow_tex, du_dv_tex, level_width, level_height);
}
- prev_level_flow_tex = du_dv_tex;
+ prev_level_flow_tex = base_flow_tex;
+ prev_level_width = level_width;
+ prev_level_height = level_height;
}
total_timer.end();
timers.print();
- int level_width = WIDTH >> finest_level;
- int level_height = HEIGHT >> finest_level;
+ int level_width = width1 >> finest_level;
+ int level_height = height1 >> finest_level;
unique_ptr<float[]> dense_flow(new float[level_width * level_height * 2]);
glGetTextureImage(prev_level_flow_tex, 0, GL_RG, GL_FLOAT, level_width * level_height * 2 * sizeof(float), dense_flow.get());
float du = dense_flow[(yy * level_width + x) * 2 + 0];
float dv = dense_flow[(yy * level_width + x) * 2 + 1];
- du = du * level_width;
- dv = -dv * level_height;
+ dv = -dv;
fwrite(&du, 4, 1, flowfp);
fwrite(&dv, 4, 1, flowfp);