colin/Megapixels
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Add color correction to the gles shader

Browse Source
This commit is contained in:
Martijn Braam
2023-07-26 23:40:51 +02:00
parent 10103a2834
commit d13cdd5dcb
7 changed files with 143 additions and 86 deletions
Download Patch File Download Diff File Expand all files Collapse all files

14
data/debayer.frag
View File

@@ -5,6 +5,7 @@ precision highp float;
uniform sampler2D texture;
uniform mat3 color_matrix;
uniform float inv_gamma;
uniform float blacklevel;
#ifdef BITS_10
uniform float row_length;
uniform float padding_ratio;
@@ -59,16 +60,9 @@ main()
vec3 color = vec3(samples.x, (samples.y + samples.z) / 2.0, samples.w);
#endif
// Some crude blacklevel correction to make the preview a bit nicer, this
// should be an uniform
vec3 corrected = color - 0.02;
/*
// Fast SRGB estimate. See https://mimosa-pudica.net/fast-gamma/
vec3 gamma_color =
(vec3(1.138) * inversesqrt(corrected) - vec3(0.138)) * corrected;
*/
color = color * color_matrix;
color -= blacklevel;
color *= 1.0-(1.0/blacklevel);
color *= color_matrix;
vec3 gamma_color = pow(color, vec3(inv_gamma));
gl_FragColor = vec4(gamma_color, 1);

75
src/gles2_debayer.c
View File

@@ -9,22 +9,6 @@
#define VERTEX_ATTRIBUTE 0
#define TEX_COORD_ATTRIBUTE 1
struct _GLES2Debayer {
int format;
GLuint frame_buffer;
GLuint program;
GLuint uniform_transform;
GLuint uniform_pixel_size;
GLuint uniform_padding_ratio;
GLuint uniform_texture;
GLuint uniform_color_matrix;
GLuint uniform_row_length;
GLuint uniform_inv_gamma;
GLuint quad;
};
GLES2Debayer *
gles2_debayer_new(int format)
{
@@ -79,6 +63,7 @@ gles2_debayer_new(int format)
self->uniform_color_matrix =
glGetUniformLocation(self->program, "color_matrix");
self->uniform_inv_gamma = glGetUniformLocation(self->program, "inv_gamma");
self->uniform_blacklevel = glGetUniformLocation(self->program, "blacklevel");
if (libmegapixels_format_bits_per_pixel(self->format) == 10)
self->uniform_row_length =
glGetUniformLocation(self->program, "row_length");
@@ -109,6 +94,39 @@ gles2_debayer_use(GLES2Debayer *self)
gl_util_bind_quad(self->quad);
}
void
gles2_debayer_set_shading(GLES2Debayer *self,
float red,
float blue,
float blacklevel)
{
if (self->forward_matrix[0]) {
float wb[9] = {
// clang-format off
red, 0, 0,
0, 1, 0,
0, 0, blue,
// clang-format on
};
float colormat[9];
float xyz[9];
float xyzd65[9];
multiply_matrices(wb, self->forward_matrix, xyz);
multiply_matrices(xyz, XYZD50_to_D65, xyzd65);
multiply_matrices(xyzd65, XYZD65_to_sRGB, colormat);
glUniformMatrix3fv(
self->uniform_color_matrix, 1, GL_FALSE, colormat);
} else {
glUniformMatrix3fv(
self->uniform_color_matrix, 1, GL_FALSE, IDENTITY);
}
check_gl();
glUniform1f(self->uniform_blacklevel, blacklevel);
check_gl();
}
void
gles2_debayer_configure(GLES2Debayer *self,
const uint32_t dst_width,
@@ -153,27 +171,14 @@ gles2_debayer_configure(GLES2Debayer *self,
}
}
glUniform1f(self->uniform_inv_gamma, 1.0f / gamma);
if (calibration.forward_matrix_1[0]) {
float colormat[9];
float xyz[9];
multiply_matrices(calibration.forward_matrix_1, XYZD50_to_D65, xyz);
multiply_matrices(xyz, XYZD65_to_sRGB, colormat);
glUniformMatrix3fv(
self->uniform_color_matrix, 1, GL_FALSE, colormat);
} else {
static const GLfloat identity[9] = {
// clang-format off
1, 0, 0,
0, 1, 0,
0, 0, 1,
// clang-format on
};
glUniformMatrix3fv(
self->uniform_color_matrix, 1, GL_FALSE, identity);
}
check_gl();
for (int i = 0; i < 9; i++) {
self->forward_matrix[i] = calibration.forward_matrix_1[i];
}
gles2_debayer_set_shading(self, 1.0f, 1.0f, 0.0f);
GLuint row_length =
libmegapixels_mode_width_to_bytes(self->format, src_width);
if (libmegapixels_format_bits_per_pixel(self->format) == 10) {

35
src/gles2_debayer.h
View File

@@ -4,7 +4,23 @@
#include <assert.h>
#include <stdio.h>
typedef struct _GLES2Debayer GLES2Debayer;
typedef struct {
int format;
float forward_matrix[9];
GLuint frame_buffer;
GLuint program;
GLint uniform_transform;
GLint uniform_pixel_size;
GLint uniform_padding_ratio;
GLint uniform_texture;
GLint uniform_color_matrix;
GLint uniform_row_length;
GLint uniform_inv_gamma;
GLint uniform_blacklevel;
GLuint quad;
} GLES2Debayer;
GLES2Debayer *gles2_debayer_new(int format);
@@ -13,12 +29,17 @@ void gles2_debayer_free(GLES2Debayer *self);
void gles2_debayer_use(GLES2Debayer *self);
void gles2_debayer_configure(GLES2Debayer *self,
const uint32_t dst_width,
const uint32_t dst_height,
const uint32_t src_width,
const uint32_t src_height,
const uint32_t rotation,
const bool mirrored,
uint32_t dst_width,
uint32_t dst_height,
uint32_t src_width,
uint32_t src_height,
uint32_t rotation,
bool mirrored,
struct MPCameraCalibration calibration);
void gles2_debayer_set_shading(GLES2Debayer *self,
float red,
float blue,
float blacklevel);
void gles2_debayer_process(GLES2Debayer *self, GLuint dst_id, GLuint source_id);

34
src/matrix.c
View File

@@ -1,15 +1,16 @@
#include "matrix.h"
#include <stdio.h>
void
print_matrix(float m[9])
{
printf(" [%.2f %.2f %.2f] \n", m[0], m[1], m[2]);
printf(" [%.2f %.2f %.2f] \n", m[3], m[4], m[5]);
printf(" [%.2f %.2f %.2f] \n\n", m[6], m[7], m[8]);
printf(" [%+.2f %+.2f %+.2f] \n", m[0], m[1], m[2]);
printf(" [%+.2f %+.2f %+.2f] \n", m[3], m[4], m[5]);
printf(" [%+.2f %+.2f %+.2f] \n\n", m[6], m[7], m[8]);
}
void
multiply_matrices(float a[9], float b[9], float out[9])
multiply_matrices(const float a[9], const float b[9], float out[9])
{
// zero out target matrix
for (int i = 0; i < 9; i++) {
@@ -24,3 +25,28 @@ multiply_matrices(float a[9], float b[9], float out[9])
}
}
}
void
invert_matrix(const float in[9], float out[9])
{
float det = in[0] * (in[4] * in[8] - in[5] * in[7]) -
in[1] * (in[3] * in[8] - in[5] * in[6]) +
in[2] * (in[3] * in[7] - in[4] * in[7]);
out[0] = (in[4] * in[8] - in[7] * in[5]) / det;
out[1] = (in[7] * in[2] - in[1] * in[8]) / det;
out[2] = (in[1] * in[5] - in[4] * in[2]) / det;
out[3] = (in[6] * in[5] - in[3] * in[8]) / det;
out[4] = (in[0] * in[8] - in[6] * in[5]) / det;
out[5] = (in[3] * in[2] - in[0] * in[5]) / det;
out[6] = (in[3] * in[7] - in[6] * in[4]) / det;
out[7] = (in[6] * in[1] - in[0] * in[7]) / det;
out[8] = (in[0] * in[4] - in[3] * in[1]) / det;
}
void
transpose_matrix(const float in[9], float out[9])
{
for (int i = 0; i < 3; ++i)
for (int j = 0; j < 3; ++j)
out[i + j * 3] = in[j + i * 3];
}

55
src/matrix.h
View File

@@ -1,34 +1,33 @@
static float XYZD50_to_D65[] = { 0.9555766f, -0.0230393f, 0.0631636f,
#pragma once
static float IDENTITY[9] = {
// clang-format off
1, 0, 0,
0, 1, 0,
0, 0, 1,
// clang-format on
};
static float XYZD50_to_D65[] = {
// clang-format off
0.9555766f, -0.0230393f, 0.0631636f,
-0.0282895f, 1.0099416f, 0.0210077f,
0.0122982f, -0.0204830f, 1.3299098f };
0.0122982f, -0.0204830f, 1.3299098f
// clang-format on
};
static float XYZD65_to_sRGB[] = { 3.2406f, -1.5372f, -0.4986f,
static float XYZD65_to_sRGB[] = {
// clang-format off
3.2406f, -1.5372f, -0.4986f,
-0.9689f, 1.8758f, 0.0415f,
0.0557f, -0.2040f, 1.0570f };
0.0557f, -0.2040f, 1.0570f
// clang-format on
};
void multiply_matrices(float a[9], float b[9], float out[9]);
void print_matrix(float m[9]);
void
invert_matrix(const float in[9], float out[9])
{
float det = in[0] * (in[4] * in[8] - in[5] * in[7]) -
in[1] * (in[3] * in[8] - in[5] * in[6]) +
in[2] * (in[3] * in[7] - in[4] * in[7]);
out[0] = (in[4] * in[8] - in[7] * in[5]) / det;
out[1] = (in[7] * in[2] - in[1] * in[8]) / det;
out[2] = (in[1] * in[5] - in[4] * in[2]) / det;
out[3] = (in[6] * in[5] - in[3] * in[8]) / det;
out[4] = (in[0] * in[8] - in[6] * in[5]) / det;
out[5] = (in[3] * in[2] - in[0] * in[5]) / det;
out[6] = (in[3] * in[7] - in[6] * in[4]) / det;
out[7] = (in[6] * in[1] - in[0] * in[7]) / det;
out[8] = (in[0] * in[4] - in[3] * in[1]) / det;
}
void multiply_matrices(const float a[9], const float b[9], float out[9]);
void
transpose_matrix(const float in[9], float out[9])
{
for (int i = 0; i < 3; ++i)
for (int j = 0; j < 3; ++j)
out[i + j * 3] = in[j + i * 3];
}
void invert_matrix(const float in[9], float out[9]);
void transpose_matrix(const float in[9], float out[9]);

8
src/process_pipeline.c
View File

@@ -473,6 +473,11 @@ process_image_for_preview(const uint8_t *image)
center);
libmegapixels_aaa_software_statistics(
center, width, height, &state_proc.stats);
state_proc.red += (state_proc.stats.whitebalance * -0.02f) + (state_proc.stats.tint * 0.01f);
state_proc.blue += (state_proc.stats.whitebalance * +0.02f) + (state_proc.stats.tint * 0.01f);
state_proc.blacklevel += state_proc.stats.blacklevel * 0.01f;
gles2_debayer_set_shading(gles2_debayer, state_proc.red, state_proc.blue, state_proc.blacklevel);
}
// Create a thumbnail from the preview for the last capture
@@ -933,6 +938,9 @@ on_output_changed(bool format_changed)
gles2_debayer_use(gles2_debayer);
}
state_proc.blacklevel = 0.0f;
state_proc.red = 1.0f;
state_proc.blue = 1.0f;
gles2_debayer_configure(gles2_debayer,
output_buffer_width,
output_buffer_height,

4
src/state.h
View File

@@ -94,4 +94,8 @@ typedef struct state_proc {
controlstate focus;
struct MPCameraCalibration calibration;
float red;
float blue;
float blacklevel;
} mp_state_proc;