From 95175afb5dd760e7654f35fd6288130e7e81cb01 Mon Sep 17 00:00:00 2001 From: Roz K Date: Thu, 18 Sep 2025 06:08:05 +0200 Subject: [PATCH] frame widening maths, cleanup --- gopro_8:7/unfish_gopro_8:7.glsl | 43 +++++------ gopro_8:7/unfish_gopro_8:7.py | 126 ++++++++++++++++++-------------- 2 files changed, 91 insertions(+), 78 deletions(-) diff --git a/gopro_8:7/unfish_gopro_8:7.glsl b/gopro_8:7/unfish_gopro_8:7.glsl index 88b8db4..151e74b 100644 --- a/gopro_8:7/unfish_gopro_8:7.glsl +++ b/gopro_8:7/unfish_gopro_8:7.glsl @@ -9,7 +9,6 @@ // #define debug_borders // uniforms - uniform sampler2DRect myTextureY; uniform sampler2DRect myTextureU; uniform sampler2DRect myTextureV; @@ -17,42 +16,41 @@ uniform vec2 myResolution; uniform float pts; // parameters - -const vec2 sensor_dimensions = vec2(5.949440, 5.205760); -const float fisheye_focal_length = 2.92; -const float rectilinear_focal_length = 2.102263; +const vec2 sensor_size = vec2(5.949440, 5.205760); const vec2 pixel_scale = vec2(0.871558, 1.0); -const int subsampling = 4; +const float equidistant_focal_length = 2.920000; +const float rectilinear_focal_length = 2.102263; // constants - -const float subsampling_step = 1.0 / float(subsampling); -const float subsampling_start = subsampling_step * 0.5 - 0.5; -const float subsampling_denominator = 1.0 / float(subsampling * subsampling); +const int subsampling = 4; +const vec2 subsampling_step = vec2(1.0 / float(subsampling)); +const vec2 subsampling_start = subsampling_step * 0.5 - vec2(0.5); +const float subsampling_scale = 1.0 / float(subsampling * subsampling); // variables - vec2 texture_center; vec2 texture_to_sensor; vec2 sensor_to_texture; void initialize() { texture_center = myResolution * 0.5; - texture_to_sensor = (sensor_dimensions / myResolution) * pixel_scale; - sensor_to_texture = (myResolution / sensor_dimensions); + texture_to_sensor = (sensor_size / myResolution) * pixel_scale; + sensor_to_texture = (myResolution / sensor_size); } vec2 unfish_coord(const in vec2 coord) { - float rectilinear_distance = length(coord); - float rectilinear_angle = atan(rectilinear_distance / rectilinear_focal_length); - float fisheye_distance = rectilinear_angle * fisheye_focal_length; - return coord * (fisheye_distance / rectilinear_distance); + float rectilinear_radius = length(coord); + float rectilinear_angle = atan(rectilinear_radius / rectilinear_focal_length); + float equidistant_radius = rectilinear_angle * equidistant_focal_length; + return coord * (equidistant_radius / rectilinear_radius); } vec4 unfish_pixel(const in vec2 coord) { vec2 unfished = unfish_coord((coord - texture_center) * texture_to_sensor); vec2 y_coord = texture_center + unfished * sensor_to_texture; + // y_coord.y = coord.y; + #ifdef debug_borders if (y_coord.x < 0.0 || y_coord.y < 0.0 || y_coord.x > myResolution.x || y_coord.y > myResolution.y) { return vec4(1.0, 1.0, 1.0, 1.0); @@ -74,13 +72,12 @@ void main() { vec2 coord = gl_TexCoord[0].xy; vec4 pixel = vec4(0.0, 0.0, 0.0, 0.0); - float x, y = subsampling_start; - for (int column = 0; column < subsampling; column++, y += subsampling_step) { - x = subsampling_start; - for (int row = 0; row < subsampling; row++, x += subsampling_step) { - pixel += unfish_pixel(coord + vec2(x, y)); + for (int y = 0; y < subsampling; y++) { + for (int x = 0; x < subsampling; x++) { + vec2 offset = subsampling_start + subsampling_step * vec2(x, y); + pixel += unfish_pixel(coord + offset); } } - gl_FragColor = pixel * subsampling_denominator; + gl_FragColor = pixel * subsampling_scale; } diff --git a/gopro_8:7/unfish_gopro_8:7.py b/gopro_8:7/unfish_gopro_8:7.py index 40599d8..8f5c66f 100644 --- a/gopro_8:7/unfish_gopro_8:7.py +++ b/gopro_8:7/unfish_gopro_8:7.py @@ -2,85 +2,101 @@ import math -print("\n--- sensor size (millimeters) ---\n") +print("\n--- physical sensor ---\n") # https://www.sony-semicon.com/files/62/pdf/p-13_IMX677-AAPH5-J_Flyer.pdf -sensor_total_array_width = 5700 # p -sensor_total_array_height = 5160 # p -sensor_total_array_diagonal = math.hypot(sensor_total_array_width, sensor_total_array_height) +sensor_array_horizontal = 5700 # p +sensor_array_vertical = 5160 # p +sensor_array_diagonal = math.hypot(sensor_array_horizontal, sensor_array_vertical) sensor_pixel_size = 1.12 * 0.001 # mm -sensor_total_width = sensor_total_array_width * sensor_pixel_size -sensor_total_height = sensor_total_array_height * sensor_pixel_size -sensor_total_diagonal = math.hypot(sensor_total_width, sensor_total_height) +sensor_size_horizontal = sensor_array_horizontal * sensor_pixel_size +sensor_size_vertical = sensor_array_vertical * sensor_pixel_size +sensor_size_diagonal = math.hypot(sensor_size_horizontal, sensor_size_vertical) -# sensor_total_diagonal = 8.35 # mm -# sensor_total_width = sensor_total_diagonal * (sensor_total_array_width / sensor_total_array_diagonal) -# sensor_total_height = sensor_total_diagonal * (sensor_total_array_height / sensor_total_array_diagonal) - -print("sensor total: width = %.6f, height = %.6f, diagonal = %.6f" % ( - sensor_total_width, - sensor_total_height, - sensor_total_diagonal)) - -sensor_active_array_width = 5599 # p -sensor_active_array_height = 4927 # p -sensor_active_array_diagonal = math.hypot(sensor_active_array_width, sensor_active_array_height) - -sensor_active_width = (sensor_active_array_width / sensor_total_array_width) * sensor_total_width -sensor_active_height = (sensor_active_array_height / sensor_total_array_height) * sensor_total_height -sensor_active_diagonal = (sensor_active_array_diagonal / sensor_total_array_diagonal) * sensor_total_diagonal - -print("sensor active: width = %.6f, height = %.6f, diagonal = %.6f" % ( - sensor_active_width, - sensor_active_height, - sensor_active_diagonal)) +print("sensor size : horizontal = %7.3f, vertical = %7.3f, diagonal = %7.3f (mm)" % ( + sensor_size_horizontal, + sensor_size_vertical, + sensor_size_diagonal)) # https://community.gopro.com/s/article/HERO11-Black-Video-Settings-And-Resolutions -gopro_array_width = 5312 # p -gopro_array_height = 4648 # p -gopro_array_diagonal = math.hypot(gopro_array_width, gopro_array_height) +gopro_array_horizontal = 5312 # p +gopro_array_vertical = 4648 # p +gopro_array_diagonal = math.hypot(gopro_array_horizontal, gopro_array_vertical) -gopro_sensor_width = (gopro_array_width / sensor_total_array_width) * sensor_total_width -gopro_sensor_height = (gopro_array_height / sensor_total_array_height) * sensor_total_height -gopro_sensor_diagonal = (gopro_array_diagonal / sensor_total_array_diagonal) * sensor_total_diagonal +gopro_size_horizontal = (gopro_array_horizontal / sensor_array_horizontal) * sensor_size_horizontal +gopro_size_vertical = (gopro_array_vertical / sensor_array_vertical) * sensor_size_vertical +gopro_size_diagonal = (gopro_array_diagonal / sensor_array_diagonal) * sensor_size_diagonal -print("gopro active: width = %.6f, height = %.6f, diagonal = %.6f" % ( - gopro_sensor_width, - gopro_sensor_height, - gopro_sensor_diagonal)) +print("gopro size : horizontal = %7.3f, vertical = %7.3f, diagonal = %7.3f (mm)" % ( + gopro_size_horizontal, + gopro_size_vertical, + gopro_size_diagonal)) -# https://thinglabs.io/gopro-focal-length-guide +# https://thinglabs.io/gopro-focal-radius-guide gopro_focal_length = 2.92 # mm -print("\n--- fisheye field of view (degrees) ---\n") +gopro_radius_horizontal = gopro_size_horizontal * 0.5 +gopro_radius_vertical = gopro_size_vertical * 0.5 +gopro_radius_diagonal = gopro_size_diagonal * 0.5 # https://en.wikipedia.org/wiki/Fisheye_lens -equidistant_angle = lambda length: math.degrees(length / gopro_focal_length) +equidistant_angle = lambda radius: math.degrees(radius / gopro_focal_length) -gopro_fov_width = 2.0 * equidistant_angle(gopro_sensor_width * 0.5) -gopro_fov_height = 2.0 * equidistant_angle(gopro_sensor_height * 0.5) -gopro_fov_diagonal = 2.0 * equidistant_angle(gopro_sensor_diagonal * 0.5) +gopro_fov_horizontal = 2.0 * equidistant_angle(gopro_radius_horizontal) +gopro_fov_vertical = 2.0 * equidistant_angle(gopro_radius_vertical) +gopro_fov_diagonal = 2.0 * equidistant_angle(gopro_radius_diagonal) -print("gopro fov: width = %.6f, height = %.6f, diagonal = %.6f" % ( - gopro_fov_width, - gopro_fov_height, +print("gopro fov : horizontal = %7.3f, vertical = %7.3f, diagonal = %7.3f (deg)" % ( + gopro_fov_horizontal, + gopro_fov_vertical, gopro_fov_diagonal)) -print("\n--- rectilinear focal length (mm) ---\n") +print("\n--- rectilinear re-projection, preserving vertical fov ---\n") -rectilinear_focal_length = lambda length: length * math.tan(math.radians(90.0 - equidistant_angle(length))) +rectilinear_focal_length = lambda radius: radius * math.tan(math.radians(90.0 - equidistant_angle(radius))) -rectilinear_focal_length_width = rectilinear_focal_length(gopro_sensor_width * 0.5) -rectilinear_focal_length_height = rectilinear_focal_length(gopro_sensor_height * 0.5) -rectilinear_focal_length_diagonal = rectilinear_focal_length(gopro_sensor_diagonal * 0.5) +rectilinear_focal_length_horizontal = rectilinear_focal_length(gopro_radius_horizontal) +rectilinear_focal_length_vertical = rectilinear_focal_length(gopro_radius_vertical) +rectilinear_focal_length_diagonal = rectilinear_focal_length(gopro_radius_diagonal) -print("rectilinear focal length: width = %.6f, height = %.6f, diagonal = %.6f" % ( - rectilinear_focal_length_width, - rectilinear_focal_length_height, +print("linear focal: horizontal = %7.3f, vertical = %7.3f, diagonal = %7.3f (mm)" % ( + rectilinear_focal_length_horizontal, + rectilinear_focal_length_vertical, rectilinear_focal_length_diagonal)) + +rectilinear_radius = lambda angle, focal_length: focal_length * math.tan(math.radians(angle)) +rectilinear_angle = lambda radius, focal_length: math.degrees(math.atan(radius / focal_length)) + +preserved_fov_horizontal = 2.0 * rectilinear_angle(gopro_radius_horizontal, rectilinear_focal_length_vertical) +preserved_fov_vertical = 2.0 * rectilinear_angle(gopro_radius_vertical, rectilinear_focal_length_vertical) +preserved_fov_diagonal = 2.0 * rectilinear_angle(gopro_radius_diagonal, rectilinear_focal_length_vertical) + +print("linear fov : horizontal = %7.3f, vertical = %7.3f, diagonal = %7.3f (deg)" % ( + preserved_fov_horizontal, + preserved_fov_vertical, + preserved_fov_diagonal)) + +print("\n--- shader parameters ---\n") + +rectilinear_angle_horizontal = rectilinear_angle(gopro_radius_horizontal, rectilinear_focal_length_horizontal) +preserved_radius_horizontal = rectilinear_radius(rectilinear_angle_horizontal, rectilinear_focal_length_vertical) + +pixel_scale = gopro_radius_horizontal / preserved_radius_horizontal + +print("""// parameters +const vec2 sensor_size = vec2(%.6f, %.6f); +const vec2 pixel_scale = vec2(%.6f, 1.0); +const float equidistant_focal_length = %.6f; +const float rectilinear_focal_length = %.6f; +""" % ( + gopro_size_horizontal, gopro_size_vertical, + pixel_scale, + gopro_focal_length, + rectilinear_focal_length_vertical) +)