m1-ENSL/seam-carving
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

format

Browse Source
This commit is contained in:
François Colin de Verdière 2025-04-03 17:01:11 +02:00
parent 739d45e7cc
commit f6e45e62b2
1 changed files with 137 additions and 146 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

283
src/seam-carving.cpp
View File

@ -1,5 +1,5 @@
#include <iostream>
#include <cassert>
#include <iostream>
#include <random>
#include <string>
#include <vector>
@ -7,9 +7,9 @@
#include <CLI11.hpp>
// Image filtering and I/O
#include <SimpleProgressBar.hpp>
#include "utils.hpp"
#include "image.h"
#include "utils.hpp"
#include <SimpleProgressBar.hpp>
#define DEFAULT_SEAMS 1
@ -23,7 +23,6 @@ int max_step = 1;
// : dim_long, b : dim_large
#define im_index(a, b) (vertical ? (width * a + b) : (width * b + a))
void export_image(const char *filename, const void *data, int width, int height,
int nbChannels) {
if (!silent)
@ -38,9 +37,10 @@ void export_image(const char *filename, const void *data, int width, int height,
std::string function = "grad";
#define compute_energy_for_pixel(source, width, height, i, j, nbChannels, \
/* computes the energy at pixel i,j, i.e. energy[width*j+i]*/ \
nbColorChannels, dest) \
#define compute_energy_for_pixel( \
source, width, height, i, j, \
nbChannels, /* computes the energy at pixel i,j, i.e. energy[width*j+i]*/ \
nbColorChannels, dest) \
auto indexPixel = (nbChannels) * (width * (j) + (i)); \
auto indexPixel_up = \
((j) - 1 > 0) ? (nbChannels) * (width * ((j) - 1) + (i)) : indexPixel; \
@ -52,53 +52,50 @@ std::string function = "grad";
auto indexPixel_right = ((i) + 1 < width) \
? (nbChannels) * (width * (j) + ((i) + 1)) \
: indexPixel; \
dest =0; \
dest = 0; \
if (function == "gradnorm") { \
for (auto ch = 0; ch < (nbColorChannels); ch++) { \
dest+= \
(std::pow(fabs((float)source[indexPixel_up + ch] - \
source[indexPixel + ch]), \
2) + \
dest += (std::pow(fabs((float)source[indexPixel_up + ch] - \
source[indexPixel + ch]), \
2) + \
\
std::pow(fabs((float)source[indexPixel_down + ch] - \
source[indexPixel + ch]), \
2) + \
std::pow(fabs((float)source[indexPixel_down + ch] - \
source[indexPixel + ch]), \
2) + \
\
std::pow(fabs((float)source[indexPixel_left + ch] - \
source[indexPixel + ch]), \
2) + \
std::pow(fabs((float)source[indexPixel_right + ch] - \
source[indexPixel + ch]), \
2)); \
std::pow(fabs((float)source[indexPixel_left + ch] - \
source[indexPixel + ch]), \
2) + \
std::pow(fabs((float)source[indexPixel_right + ch] - \
source[indexPixel + ch]), \
2)); \
} \
} else if (function == "grad") { \
for (auto ch = 0; ch < (nbColorChannels); ch++) { \
dest += \
((fabs((float)source[indexPixel_up + ch] - \
source[indexPixel + ch])) + \
dest += ((fabs((float)source[indexPixel_up + ch] - \
source[indexPixel + ch])) + \
\
(fabs((float)source[indexPixel_down + ch] - \
source[indexPixel + ch])) + \
(fabs((float)source[indexPixel_down + ch] - \
source[indexPixel + ch])) + \
\
(fabs((float)source[indexPixel_left + ch] - \
source[indexPixel + ch])) + \
(fabs((float)source[indexPixel_right + ch] - \
source[indexPixel + ch]))); \
(fabs((float)source[indexPixel_left + ch] - \
source[indexPixel + ch])) + \
(fabs((float)source[indexPixel_right + ch] - \
source[indexPixel + ch]))); \
} \
} else if (function == "gradnorminf") { \
for (auto ch = 0; ch < (nbColorChannels); ch++) { \
dest+= \
std::max(std::max((fabs((float)source[indexPixel_up + ch] - \
source[indexPixel + ch])), \
dest += std::max(std::max((fabs((float)source[indexPixel_up + ch] - \
source[indexPixel + ch])), \
\
(fabs((float)source[indexPixel_down + ch] - \
source[indexPixel + ch]))), \
std::max( \
(fabs((float)source[indexPixel_down + ch] - \
source[indexPixel + ch]))), \
std::max( \
\
(fabs((float)source[indexPixel_left + ch] - \
source[indexPixel + ch])), \
(fabs((float)source[indexPixel_right + ch] - \
source[indexPixel + ch])))); \
(fabs((float)source[indexPixel_left + ch] - \
source[indexPixel + ch])), \
(fabs((float)source[indexPixel_right + ch] - \
source[indexPixel + ch])))); \
} \
} else { \
std::cerr << "function " << function << " not available" << std::endl; \
@ -118,17 +115,16 @@ std::vector<float> energy_e1(std::vector<unsigned char> source, int width,
for (auto i = 0; i < width; i++) {
for (auto j = 0; j < height; j++) {
compute_energy_for_pixel(
source, width, height,
i, j, nbChannels, nbColorChannels, energy[width*j+i]
);
compute_energy_for_pixel(source, width, height, i, j, nbChannels,
nbColorChannels, energy[width * j + i]);
}
}
return energy;
}
/** Given the energy value, returns the optimal seam */
template <typename T> std::vector<int> optimal_seam(std::vector<T> energy, int width, int height,
template <typename T>
std::vector<int> optimal_seam(std::vector<T> energy, int width, int height,
bool vertical) {
// dyn_energy is indexed by [dim_large*(i : dim_long) + (j : dim_large)]
@ -150,9 +146,10 @@ template <typename T> std::vector<int> optimal_seam(std::vector<T> energy, int w
for (auto k = lower_bound; k <= upper_bound;
k++) { // Compute energy based on predecessors
if (dyn_energy[dim_large*(i-1)+k] < dyn_energy[dim_large*i+j]) {
dyn_energy[dim_large*i+j] = dyn_energy[dim_large*(i-1)+k];
}
if (dyn_energy[dim_large * (i - 1) + k] <
dyn_energy[dim_large * i + j]) {
dyn_energy[dim_large * i + j] = dyn_energy[dim_large * (i - 1) + k];
}
}
dyn_energy[dim_large * i + j] += energy[im_index(i, j)];
}
@ -173,15 +170,15 @@ template <typename T> std::vector<int> optimal_seam(std::vector<T> energy, int w
//* Backtracking to find the path
for (auto i = dim_long - 1; i > 0; i--) {
// We want to find either (bot_l, bot_c, bot_r) with dyn_energy[.] = min_val -
// energy[cur]
// We want to find either (bot_l, bot_c, bot_r) with dyn_energy[.] = min_val -
// energy[cur]
// Idea : float next_energy = min_val - energy[width*i + min_idx];
//! With floats, we don't always have x + y - y == x, so we check is x+y == x+y
// This define is a bit ugly but 200x faster than using a lambda function
#define is_next_idx(idx) \
(dyn_energy[(i - 1) * dim_large + idx] + energy[im_index(i, min_idx)] == \
min_val)
// Idea : float next_energy = min_val - energy[width*i + min_idx];
//! With floats, we don't always have x + y - y == x, so we check is x+y == x+y
// This define is a bit ugly but 200x faster than using a lambda function
#define is_next_idx(idx) \
(dyn_energy[(i - 1) * dim_large + idx] + energy[im_index(i, min_idx)] == \
min_val)
// This is not the nicest way to do this but we want to check in priority
// at the center to have straight seams
@ -239,59 +236,56 @@ void remove_seam(const std::vector<T> source, std::vector<T> &output, int width,
}
}
// It would be preferable to use templates only for the value assignation but this is in fact far less efficient
void recompute_energy_along_seam(
std::vector<unsigned char> carved_img, std::vector<float> &output_energy, std::vector<int> opt_seam,
int width, int height, int nbChannels, int nbColorChannels, bool vertical
) {
// It would be preferable to use templates only for the value assignation but
// this is in fact far less efficient
void recompute_energy_along_seam(std::vector<unsigned char> carved_img,
std::vector<float> &output_energy,
std::vector<int> opt_seam, int width,
int height, int nbChannels,
int nbColorChannels, bool vertical) {
int dim_large = vertical ? width : height;
int dim_long = vertical ? height : width;
int newWidth = vertical ? width-1 : width;
int newHeight = vertical ? height : height-1;
int newWidth = vertical ? width - 1 : width;
int newHeight = vertical ? height : height - 1;
for (auto j = 0; j < dim_long; j++) {
for (auto i = -1; i < 2; i++) {
int x = vertical ? (opt_seam[j] + i) : j;
int y = vertical ? j : (opt_seam[j] + i);
if ((0 < (opt_seam[j] + i)) && ((opt_seam[j] + i) < dim_large - 1)) {
compute_energy_for_pixel(
carved_img, newWidth, newHeight,
x, y, nbChannels,
nbColorChannels, output_energy[width*y+x]
);
compute_energy_for_pixel(carved_img, newWidth, newHeight, x, y,
nbChannels, nbColorChannels,
output_energy[width * y + x]);
}
}
}
}
void recompute_energy_along_seam(
std::vector<unsigned char> carved_img, std::vector<std::pair<int, float>> &output_energy, std::vector<int> opt_seam,
int width, int height, int nbChannels, int nbColorChannels, bool vertical
) {
std::vector<unsigned char> carved_img,
std::vector<std::pair<int, float>> &output_energy,
std::vector<int> opt_seam, int width, int height, int nbChannels,
int nbColorChannels, bool vertical) {
int dim_large = vertical ? width : height;
int dim_long = vertical ? height : width;
int newWidth = vertical ? width-1 : width;
int newHeight = vertical ? height : height-1;
int newWidth = vertical ? width - 1 : width;
int newHeight = vertical ? height : height - 1;
for (auto j = 0; j < dim_long; j++) {
for (auto i = -1; i < 2; i++) {
int x = vertical ? (opt_seam[j] + i) : j;
int y = vertical ? j : (opt_seam[j] + i);
if ((0 < (opt_seam[j] + i)) && ((opt_seam[j] + i) < dim_large - 1)) {
compute_energy_for_pixel(
carved_img, newWidth, newHeight,
x, y, nbChannels,
nbColorChannels, output_energy[width*y+x].first
);
compute_energy_for_pixel(carved_img, newWidth, newHeight, x, y,
nbChannels, nbColorChannels,
output_energy[width * y + x].first);
}
}
}
}
/** Carves an image and its energy by one seam, and recomputes the energy.
Returns the optimal seam used */
template <typename T>
@ -309,45 +303,41 @@ std::vector<int> carving_step(const std::vector<unsigned char> source_img,
opt_seam);
remove_seam(source_energy, output_energy, width, height, 1, vertical,
opt_seam);
// Recompute the energy along the seam, we need a separate function for templating
recompute_energy_along_seam(
source_img, output_energy, opt_seam,
width, height, nbChannels, nbColorChannels,
vertical
);
// Recompute the energy along the seam, we need a separate function for
// templating
recompute_energy_along_seam(source_img, output_energy, opt_seam, width,
height, nbChannels, nbColorChannels, vertical);
return opt_seam;
}
std::vector<std::pair<int, float>> mask_energy(std::vector<float> energy,
int width, int height, unsigned char* mask) {
std::vector<std::pair<int, float>> output(width*height);
int width, int height,
unsigned char *mask) {
std::vector<std::pair<int, float>> output(width * height);
for (auto i=0; i < width*height; i++) {
for (auto i = 0; i < width * height; i++) {
output[i] = {mask[i], energy[i]};
}
return output;
}
bool does_seam_remove_mask(unsigned char* mask, int width, int height, int nbChannels,
std::vector<int> opt_seam, bool vertical)
{
bool does_seam_remove_mask(unsigned char *mask, int width, int height,
int nbChannels, std::vector<int> opt_seam,
bool vertical) {
int dim_large = vertical ? width : height;
int dim_long = vertical ? height : width;
for (int i=0; i < dim_long; i++) {
if (mask[im_index(i, opt_seam[i])] == 0) return true;
for (int i = 0; i < dim_long; i++) {
if (mask[im_index(i, opt_seam[i])] == 0)
return true;
}
return false;
}
auto seam_carving(unsigned char *source, int width, int height, int nbChannels,
int nbSeams, bool vertical, unsigned char* mask=nullptr) {
auto seam_carving(unsigned char *source, int width, int height, int nbChannels,
int nbSeams, bool vertical, unsigned char *mask = nullptr) {
int nbColorChannels = nbChannels > 3 ? 3 : nbChannels;
int curWidth = width;
@ -362,7 +352,7 @@ auto seam_carving(unsigned char *source, int width, int height, int nbChannels,
std::vector<float> source_energy(width * height);
// Contains at each step the carved energy
std::vector<std::pair<int, float>> masked_energy;
std::vector<std::pair<int, float>> output_masked_energy(width*height);
std::vector<std::pair<int, float>> output_masked_energy(width * height);
// Source energy with (-1, 0, 1) on first element according to mask value
std::vector<unsigned char> output_img(width * height * nbChannels);
// Receives at each step the newly carved image
@ -413,8 +403,8 @@ auto seam_carving(unsigned char *source, int width, int height, int nbChannels,
if (mask) {
if (mask[k] == 2) // Green
test_energy_output[nbChannels*k + 1] = 125;
else if (mask[k] == 0) {// Red
test_energy_output[nbChannels * k + 1] = 125;
else if (mask[k] == 0) { // Red
test_energy_output[nbChannels * k] = 125;
}
}
@ -428,28 +418,26 @@ auto seam_carving(unsigned char *source, int width, int height, int nbChannels,
while (seam_index++ < nbSeams || until_mask_removal) {
std::vector<int> opt_seam;
if (mask) {
opt_seam = carving_step(
source_img, masked_energy, output_img, output_masked_energy,
curWidth, curHeight, nbChannels, nbColorChannels, vertical
);
opt_seam = carving_step(source_img, masked_energy, output_img,
output_masked_energy, curWidth, curHeight,
nbChannels, nbColorChannels, vertical);
if (
until_mask_removal &&
!does_seam_remove_mask(mask, width, height, nbChannels, opt_seam, vertical)
) break;
if (until_mask_removal &&
!does_seam_remove_mask(mask, width, height, nbChannels, opt_seam,
vertical))
break;
} else {
opt_seam = carving_step(
source_img, source_energy, output_img, output_energy,
curWidth, curHeight, nbChannels, nbColorChannels, vertical
);
opt_seam = carving_step(source_img, source_energy, output_img,
output_energy, curWidth, curHeight, nbChannels,
nbColorChannels, vertical);
}
std::copy(output_img.begin(), output_img.end(), source_img.begin());
std::copy(output_energy.begin(), output_energy.end(),
source_energy.begin());
if (mask)
std::copy(output_masked_energy.begin(), output_masked_energy.end(),
masked_energy.begin());
masked_energy.begin());
vertical ? curWidth-- : curHeight--; // We just reduced the dimension
@ -512,8 +500,9 @@ int main(int argc, char **argv) {
"Don't resize image, just try the specified energy function");
app.add_option("-f,--function", function,
"The function to apply to compute the energy");
app.add_flag("-u,--until-mask-removal", until_mask_removal,
"Carve the image until there are no more red pixels in the mask");
app.add_flag(
"-u,--until-mask-removal", until_mask_removal,
"Carve the image until there are no more red pixels in the mask");
CLI11_PARSE(app, argc, argv);
// Image loading
@ -525,42 +514,44 @@ int main(int argc, char **argv) {
if (!maskImage.empty()) {
int maskWidth, maskHeight, maskChannels;
mask =
stbi_load(maskImage.c_str(), &maskWidth, &maskHeight, &maskChannels, 0);
stbi_load(maskImage.c_str(), &maskWidth, &maskHeight, &maskChannels, 0);
if (maskWidth != width || maskHeight != height) {
std::cerr << maskImage << " and " << sourceImage
<< " differ in dimension. Please provide a valid mask."
<< std::endl;
exit(1);
}
if (maskChannels < 3) {
std::cerr << maskImage << " needs to be RGB." << std::endl;
exit(1);
}
unsigned char r, g, b;
for (auto i=0; i < width*height; i++) {
r = mask[maskChannels*i];
g = mask[maskChannels*i+1];
b = mask[maskChannels*i+2];
bool positive = (g > r && g > b && g > 100); // Mask images are not always the cleanest
bool negative = (r > g && r > b && r > 100);
if (maskWidth != width || maskHeight != height) {
std::cerr << maskImage << " and " << sourceImage
<< " differ in dimension. Please provide a valid mask."
<< std::endl;
exit(1);
}
if (maskChannels < 3) {
std::cerr << maskImage << " needs to be RGB." << std::endl;
exit(1);
}
unsigned char r, g, b;
for (auto i = 0; i < width * height; i++) {
r = mask[maskChannels * i];
g = mask[maskChannels * i + 1];
b = mask[maskChannels * i + 2];
bool positive = (g > r && g > b &&
g > 100); // Mask images are not always the cleanest
bool negative = (r > g && r > b && r > 100);
mask[i] = positive ? 2 : (negative ? 0 : 1);
}
//* From now on, mask has the same dimensions as source and one single channel
//* The values are:
//* . (2) we want to keep the pixel
//* . (1) nothing in particular
//* . (0) we want to remove the pixel
}
mask[i] = positive ? 2 : (negative ? 0 : 1);
}
//* From now on, mask has the same dimensions as source and one single
//channel
//* The values are:
//* . (2) we want to keep the pixel
//* . (1) nothing in particular
//* . (0) we want to remove the pixel
}
if (until_mask_removal && maskImage.empty()) {
std::cerr << "Flag --until-mask-removal but no mask provided." << std::endl;
until_mask_removal = false;
}
if (until_mask_removal && nbSeams != DEFAULT_SEAMS) {
std::cerr << "Flag --nb-seams specified but --until-mask-removal provided." << std::endl;
std::cerr << "Flag --nb-seams specified but --until-mask-removal provided."
<< std::endl;
nbSeams = DEFAULT_SEAMS;
}
nbSeams = std::min(