OpenCV_4.2.0/opencv_contrib-4.2.0/modules/xphoto/test/test_grayworld.cpp

100 lines
3.5 KiB
C++

// This file is part of OpenCV project.
// It is subject to the license terms in the LICENSE file found in the top-level directory
// of this distribution and at http://opencv.org/license.html.
#include "test_precomp.hpp"
namespace opencv_test { namespace {
void ref_autowbGrayworld(InputArray _src, OutputArray _dst, float thresh)
{
Mat src = _src.getMat();
_dst.create(src.size(), src.type());
Mat dst = _dst.getMat();
int width = src.cols,
height = src.rows,
N = width*height,
N3 = N*3;
// Calculate sum of pixel values of each channel
const uchar* src_data = src.ptr<uchar>(0);
unsigned long sum1 = 0, sum2 = 0, sum3 = 0;
int i = 0;
unsigned int minRGB, maxRGB, thresh255 = cvRound(thresh * 255);
for ( ; i < N3; i += 3 )
{
minRGB = std::min(src_data[i], std::min(src_data[i + 1], src_data[i + 2]));
maxRGB = std::max(src_data[i], std::max(src_data[i + 1], src_data[i + 2]));
if ( (maxRGB - minRGB) * 255 > thresh255 * maxRGB ) continue;
sum1 += src_data[i];
sum2 += src_data[i + 1];
sum3 += src_data[i + 2];
}
// Find inverse of averages
double inv1 = sum1 == 0 ? 0.f : (double)N / (double)sum1,
inv2 = sum2 == 0 ? 0.f : (double)N / (double)sum2,
inv3 = sum3 == 0 ? 0.f : (double)N / (double)sum3;
// Find maximum
double inv_max = std::max(std::max(inv1, inv2), inv3);
// Scale by maximum
if ( inv_max > 0 )
{
inv1 = (double) inv1 / inv_max;
inv2 = (double) inv2 / inv_max;
inv3 = (double) inv3 / inv_max;
}
// Fixed point arithmetic, mul by 2^8 then shift back 8 bits
int i_inv1 = cvRound(inv1 * (1 << 8)),
i_inv2 = cvRound(inv2 * (1 << 8)),
i_inv3 = cvRound(inv3 * (1 << 8));
// Scale input pixel values
uchar* dst_data = dst.ptr<uchar>(0);
i = 0;
for ( ; i < N3; i += 3 )
{
dst_data[i] = (uchar)((src_data[i] * i_inv1) >> 8);
dst_data[i + 1] = (uchar)((src_data[i + 1] * i_inv2) >> 8);
dst_data[i + 2] = (uchar)((src_data[i + 2] * i_inv3) >> 8);
}
}
TEST(xphoto_grayworld_white_balance, regression)
{
String dir = cvtest::TS::ptr()->get_data_path() + "cv/xphoto/simple_white_balance/";
const int nTests = 8;
const float wb_thresh = 0.5f;
const float acc_thresh = 2.f;
Ptr<xphoto::GrayworldWB> wb = xphoto::createGrayworldWB();
wb->setSaturationThreshold(wb_thresh);
for ( int i = 0; i < nTests; ++i )
{
String srcName = dir + format("sources/%02d.png", i + 1);
Mat src = imread(srcName, IMREAD_COLOR);
ASSERT_TRUE(!src.empty());
Mat referenceResult;
ref_autowbGrayworld(src, referenceResult, wb_thresh);
Mat currentResult;
wb->balanceWhite(src, currentResult);
ASSERT_LE(cv::norm(currentResult, referenceResult, NORM_INF), acc_thresh);
// test the 16-bit depth:
Mat currentResult_16U, src_16U;
src.convertTo(src_16U, CV_16UC3, 256.0);
wb->balanceWhite(src_16U, currentResult_16U);
currentResult_16U.convertTo(currentResult, CV_8UC3, 1/256.0);
ASSERT_LE(cv::norm(currentResult, referenceResult, NORM_INF), acc_thresh);
}
}
}} // namespace