potok/opencv
1
0
Fork 0
mirror of https://github.com/opencv/opencv.git synced 2026-07-30 07:43:03 +04:00
Code Packages Releases Wiki Activity

Merge pull request #26859 from Kumataro:fix26858

Browse Source 
imgcodecs:gif: support IMREAD_UNCHANGED and IMREAD_GRAYSCALE #26859

Close #26858 

### 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
- [x] There is a reference to the original bug report and related work
- [x] There is accuracy test, performance test and test data in opencv_extra repository, if applicable
      Patch to opencv_extra has the same branch name.
- [x] The feature is well documented and sample code can be built with the project CMake
This commit is contained in:
Kumataro
2025-02-07 01:29:54 +09:00
committed by GitHub
parent 7563cebad5
commit 01e3fe8791
4 changed files with 78 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files
modules/imgcodecs/src/grfmt_gif.cpp
+28 -3
View File
@@ -14,7 +14,7 @@ namespace cv
//////////////////////////////////////////////////////////////////////
GifDecoder::GifDecoder() {
m_signature = R"(GIF)";
m_type = CV_8UC4;
m_type = CV_8UC3;
bgColor = -1;
m_buf_supported = true;
globalColorTableSize = 0;
@@ -172,12 +172,17 @@ bool GifDecoder::readData(Mat &img) {
} else {
cvtColor(img_, img, COLOR_BGRA2BGR);
}
} else {
} else if (img.channels() == 4){
if (m_use_rgb) {
cvtColor(img_, img, COLOR_BGRA2RGBA);
} else {
img_.copyTo(img);
}
} else if (img.channels() == 1){
cvtColor(img_, img, COLOR_BGRA2GRAY);
} else {
CV_LOG_WARNING(NULL, cv::format("Unsupported channels: %d", img.channels()));
hasRead = false;
}
}
@@ -414,6 +419,7 @@ bool GifDecoder::getFrameCount_() {
if (extension == 0xFF) {
int len = m_strm.getByte();
while (len) {
// TODO: In strictly, Application Identifier and Authentication Code should be checked.
if (len == 3) {
if (m_strm.getByte() == 0x01) {
m_animation.loop_count = m_strm.getWord();
@@ -427,9 +433,28 @@ bool GifDecoder::getFrameCount_() {
}
len = m_strm.getByte();
}
} else if (extension == 0xF9) {
int len = m_strm.getByte();
while (len) {
if (len == 4) {
int packedFields = m_strm.getByte();
// 3 bit : Reserved
// 3 bit : Disposal Method
// 1 bit : User Input Flag
// 1 bit : Transparent Color Flag
if ( (packedFields & 0x01)== 0x01) {
m_type = CV_8UC4; // Transparent Index is given.
}
m_strm.skip(2); // Delay Time
m_strm.skip(1); // Transparent Color Index
} else {
m_strm.skip(len);
}
len = m_strm.getByte();
}
} else {
// if it does not belong to any of the extension type mentioned in the GIF Specification
if (extension != 0xF9 && extension != 0xFE && extension != 0x01) {
if (extension != 0xFE && extension != 0x01) {
CV_LOG_WARNING(NULL, "found Unknown Extension Type: " + std::to_string(extension));
}
int len = m_strm.getByte();