weston/tests/visualization/weston_plot_rgb_diff_stat.m

78 lines
1.9 KiB
Matlab

% -- weston_plot_rgb_diff_stat (fname)
% -- weston_plot_rgb_diff_stat (fname, scale)
% -- weston_plot_rgb_diff_stat (fname, scale, x_column)
% Plot an rgb_diff_stat dump file
%
% Creates a new figure and draws four sub-plots: R difference,
% G difference, B difference, and two-norm error.
%
% Scale defaults to 255. It is used to multiply both x and y values
% in all plots. Note that R, G and B plots will contain horizontal lines
% at y = +/- 0.5 to help you see the optimal rounding error range for
% the integer encoding [0, scale]. Two-norm plot contains a horizontal
% line at y = sqrt(0.75) which represents an error sphere with the radius
% equal to the two-norm of RGB error (0.5, 0.5, 0.5).
%
% By default, x-axis is sample index, not multiplied by scale. If
% x_column is given, it is a column index in the dump file to be used as
% the x-axis values, multiplied by scale. Indices start from 1, not 0.
% SPDX-FileCopyrightText: 2022 Collabora, Ltd.
% SPDX-License-Identifier: MIT
function weston_plot_rgb_diff_stat(fname, scale, x_column);
S = load(fname);
if nargin < 2
scale = 255;
end
if nargin < 3
x = 1:size(S, 1);
else
x = S(:, x_column) .* scale;
end
x_lim = [min(x) max(x)];
evec = S(:, 1) .* scale; # two-norm error
rvec = S(:, 2) .* scale; # r diff
gvec = S(:, 3) .* scale; # g diff
bvec = S(:, 4) .* scale; # b diff
figure
subplot(4, 1, 1);
plot(x, rvec, 'r');
plus_minus_half_lines(x_lim);
title(fname, "Interpreter", "none");
ylabel('R diff');
axis("tight");
subplot(4, 1, 2);
plot(x, gvec, 'g');
plus_minus_half_lines(x_lim);
ylabel('G diff');
axis("tight");
subplot(4, 1, 3);
plot(x, bvec, 'b');
plus_minus_half_lines(x_lim);
ylabel('B diff');
axis("tight");
subplot(4, 1, 4);
plot(x, evec, 'k');
hold on;
plot(x_lim, [1 1] .* sqrt(0.75), 'k:');
ylabel('Two-norm');
axis("tight");
max_abs_err = [max(abs(rvec)) max(abs(gvec)) max(abs(bvec))]
function plus_minus_half_lines(x_lim);
hold on;
plot(x_lim, [0.5 -0.5; 0.5 -0.5], 'k:');