opencv/modules/imgcodecs/test/test_webp.cpp
zihaomu 934e6899f8
Merge pull request #25809 from zihaomu:imread_rgb_flag
imgcodecs: Add rgb flag for imread and imdecode #25809

Try to `imread` images by RGB to save R-B swapping costs.

## How to use it?
```
img_rgb = cv2.imread("PATH", IMREAD_COLOR_RGB) # OpenCV decode the image by RGB format.
```

## TODO
- [x] Fix the broken code
- [x] Add imread rgb test
- [x] Speed test of rgb mode.

## Performance test

| file name | IMREAD_COLOR  | IMREAD_COLOR_RGB |
| --------- | ------ | --------- |
| jpg01     | 284 ms | 277 ms    |
| jpg02     | 376 ms | 366 ms    |
| png01     | 62 ms  | 60 ms     |
| Png02     | 97 ms  | 94 ms     |

Test with [image_test.zip](https://github.com/user-attachments/files/15982949/image_test.zip)
```.cpp
string img_path = "/Users/mzh/work/data/image_test/png02.png";
int loop = 20;

TickMeter t;

double t0 = 10000;
for (int i = 0; i < loop; i++)
{
    t.reset();
    t.start();
    img_bgr = imread(img_path, IMREAD_COLOR);
    t.stop();

    if (t.getTimeMilli() < t0) t0 = t.getTimeMilli();
}

std::cout<<"bgr time = "<<t0<<std::endl;

t0 = 10000;
for (int i = 0; i < loop; i++)
{
    t.reset();
    t.start();
    img_rgb = imread(img_path, IMREAD_COLOR_RGB);
    t.stop();
    if (t.getTimeMilli() < t0) t0 = t.getTimeMilli();
}
std::cout<<"rgb time = "<<t0<<std::endl;
``` 
### Pull Request Readiness Checklist

See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request

- [x] I agree to contribute to the project under Apache 2 License.
- [x] To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV
- [x] The PR is proposed to the proper branch
- [ ] There is a reference to the original bug report and related work
- [ ] There is accuracy test, performance test and test data in opencv_extra repository, if applicable
      Patch to opencv_extra has the same branch name.
- [ ] The feature is well documented and sample code can be built with the project CMake
2024-07-03 10:58:25 +03:00

121 lines
3.4 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 {
#ifdef HAVE_WEBP
TEST(Imgcodecs_WebP, encode_decode_lossless_webp)
{
const string root = cvtest::TS::ptr()->get_data_path();
string filename = root + "../cv/shared/lena.png";
cv::Mat img = cv::imread(filename);
ASSERT_FALSE(img.empty());
string output = cv::tempfile(".webp");
EXPECT_NO_THROW(cv::imwrite(output, img)); // lossless
cv::Mat img_webp = cv::imread(output);
std::vector<unsigned char> buf;
FILE * wfile = NULL;
wfile = fopen(output.c_str(), "rb");
if (wfile != NULL)
{
fseek(wfile, 0, SEEK_END);
size_t wfile_size = ftell(wfile);
fseek(wfile, 0, SEEK_SET);
buf.resize(wfile_size);
size_t data_size = fread(&buf[0], 1, wfile_size, wfile);
if(wfile)
{
fclose(wfile);
}
if (data_size != wfile_size)
{
EXPECT_TRUE(false);
}
}
EXPECT_EQ(0, remove(output.c_str()));
cv::Mat decode = cv::imdecode(buf, IMREAD_COLOR);
ASSERT_FALSE(decode.empty());
EXPECT_TRUE(cvtest::norm(decode, img_webp, NORM_INF) == 0);
cv::Mat decode_rgb = cv::imdecode(buf, IMREAD_COLOR_RGB);
ASSERT_FALSE(decode_rgb.empty());
cvtColor(decode_rgb, decode_rgb, COLOR_RGB2BGR);
EXPECT_TRUE(cvtest::norm(decode_rgb, img_webp, NORM_INF) == 0);
ASSERT_FALSE(img_webp.empty());
EXPECT_TRUE(cvtest::norm(img, img_webp, NORM_INF) == 0);
}
TEST(Imgcodecs_WebP, encode_decode_lossy_webp)
{
const string root = cvtest::TS::ptr()->get_data_path();
std::string input = root + "../cv/shared/lena.png";
cv::Mat img = cv::imread(input);
ASSERT_FALSE(img.empty());
for(int q = 100; q>=0; q-=20)
{
std::vector<int> params;
params.push_back(IMWRITE_WEBP_QUALITY);
params.push_back(q);
string output = cv::tempfile(".webp");
EXPECT_NO_THROW(cv::imwrite(output, img, params));
cv::Mat img_webp = cv::imread(output);
EXPECT_EQ(0, remove(output.c_str()));
EXPECT_FALSE(img_webp.empty());
EXPECT_EQ(3, img_webp.channels());
EXPECT_EQ(512, img_webp.cols);
EXPECT_EQ(512, img_webp.rows);
}
}
TEST(Imgcodecs_WebP, encode_decode_with_alpha_webp)
{
const string root = cvtest::TS::ptr()->get_data_path();
std::string input = root + "../cv/shared/lena.png";
cv::Mat img = cv::imread(input);
ASSERT_FALSE(img.empty());
std::vector<cv::Mat> imgs;
cv::split(img, imgs);
imgs.push_back(cv::Mat(imgs[0]));
imgs[imgs.size() - 1] = cv::Scalar::all(128);
cv::merge(imgs, img);
string output = cv::tempfile(".webp");
EXPECT_NO_THROW(cv::imwrite(output, img));
cv::Mat img_webp = cv::imread(output, IMREAD_UNCHANGED);
cv::Mat img_webp_bgr = cv::imread(output); // IMREAD_COLOR by default
EXPECT_EQ(0, remove(output.c_str()));
EXPECT_FALSE(img_webp.empty());
EXPECT_EQ(4, img_webp.channels());
EXPECT_EQ(512, img_webp.cols);
EXPECT_EQ(512, img_webp.rows);
EXPECT_FALSE(img_webp_bgr.empty());
EXPECT_EQ(3, img_webp_bgr.channels());
EXPECT_EQ(512, img_webp_bgr.cols);
EXPECT_EQ(512, img_webp_bgr.rows);
}
#endif // HAVE_WEBP
}} // namespace