opencv/modules/imgcodecs/perf/perf_png.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

64 lines
1.4 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 "perf_precomp.hpp"
namespace opencv_test
{
#if defined(HAVE_PNG) || defined(HAVE_SPNG)
using namespace perf;
typedef perf::TestBaseWithParam<std::string> PNG;
PERF_TEST(PNG, decode)
{
String filename = getDataPath("perf/2560x1600.png");
FILE *f = fopen(filename.c_str(), "rb");
fseek(f, 0, SEEK_END);
long len = ftell(f);
fseek(f, 0, SEEK_SET);
vector<uchar> file_buf((size_t)len);
EXPECT_EQ(len, (long)fread(&file_buf[0], 1, (size_t)len, f));
fclose(f); f = NULL;
TEST_CYCLE() imdecode(file_buf, IMREAD_UNCHANGED);
SANITY_CHECK_NOTHING();
}
PERF_TEST(PNG, decode_rgb)
{
String filename = getDataPath("perf/2560x1600.png");
FILE *f = fopen(filename.c_str(), "rb");
fseek(f, 0, SEEK_END);
long len = ftell(f);
fseek(f, 0, SEEK_SET);
vector<uchar> file_buf((size_t)len);
EXPECT_EQ(len, (long)fread(&file_buf[0], 1, (size_t)len, f));
fclose(f); f = NULL;
TEST_CYCLE() imdecode(file_buf, IMREAD_COLOR_RGB);
SANITY_CHECK_NOTHING();
}
PERF_TEST(PNG, encode)
{
String filename = getDataPath("perf/2560x1600.png");
cv::Mat src = imread(filename);
vector<uchar> buf;
TEST_CYCLE() imencode(".png", src, buf);
SANITY_CHECK_NOTHING();
}
#endif // HAVE_PNG
} // namespace