chore: import upstream snapshot with attribution

tools/cv/test/imgcodecs/codecs_test.cpp

@@ -0,0 +1,105 @@
+//
+//  codecs_test.cpp
+//  MNN
+//
+//  Created by MNN on 2021/08/26.
+//  Copyright © 2018, Alibaba Group Holding Limited
+//
+
+#include <gtest/gtest.h>
+#include <opencv2/imgcodecs.hpp>
+#include "cv/imgcodecs.hpp"
+#include "test_env.hpp"
+
+#ifdef MNN_CODECS_TEST
+
+static Env<uint8_t> testEnv(img_name, false);
+
+// haveImageReader
+TEST(haveImageReader, jpg) {
+    auto cvHave = cv::haveImageReader(img_name);
+    auto mnnHave = haveImageReader(img_name);
+    EXPECT_EQ(cvHave, mnnHave);
+}
+
+TEST(haveImageReader, jpg_wrongname) {
+    const char* name = "./imgs/cat__";
+    auto cvHave = cv::haveImageReader(name);
+    auto mnnHave = haveImageReader(name);
+    EXPECT_EQ(cvHave, mnnHave);
+}
+
+TEST(haveImageReader, fake_jpg) {
+    const char* name = "./imgs/fake.jpg";
+    auto cvHave = cv::haveImageReader(name);
+    auto mnnHave = haveImageReader(name);
+    EXPECT_EQ(cvHave, mnnHave);
+}
+
+// haveImageWriter
+TEST(haveImageWriter, jpg) {
+    const char* name = "x.jpg";
+    auto cvHave = cv::haveImageWriter(name);
+    auto mnnHave = haveImageWriter(name);
+    EXPECT_EQ(cvHave, mnnHave);
+}
+
+TEST(haveImageWriter, JPEG) {
+    const char* name = "x.JPEG";
+    auto cvHave = cv::haveImageWriter(name);
+    auto mnnHave = haveImageWriter(name);
+    EXPECT_EQ(cvHave, mnnHave);
+}
+
+TEST(haveImageWriter, txt) {
+    const char* name = "x.txt";
+    auto cvHave = cv::haveImageWriter(name);
+    auto mnnHave = haveImageWriter(name);
+    EXPECT_EQ(cvHave, mnnHave);
+}
+
+// imdecode
+TEST(imdecode, IMREAD_COLOR) {
+    FILE* pFile = fopen(img_name, "rb");
+    fseek(pFile, 0, SEEK_END);
+    long lSize = ftell(pFile);
+    rewind(pFile);
+    std::vector<unsigned char> data(lSize);
+    fread(data.data(), sizeof(char), lSize, pFile);
+    fclose(pFile);
+    auto cvImg = cv::imdecode(data, cv::IMREAD_COLOR);
+    auto mnnImg = imdecode(data, IMREAD_COLOR);
+    EXPECT_TRUE(testEnv.equal(cvImg, mnnImg));
+}
+
+// imencode
+TEST(imencode, jpg) {
+    std::vector<uint8_t> cvBuf;
+    cv::imencode(".jpg", testEnv.cvSrc, cvBuf);
+    auto mnnRes = imencode(".jpg", testEnv.mnnSrc);
+    // stbi_encode NOT fully equal to opencv, but is right
+    EXPECT_EQ(memcmp(cvBuf.data(), mnnRes.second.data(), 16), 0);
+}
+
+
+// imread
+TEST(imread, IMREAD_COLOR) {
+    auto cvImg = cv::imread(img_name);
+    auto mnnImg = imread(img_name);
+    EXPECT_TRUE(testEnv.equal(cvImg, mnnImg));
+}
+
+TEST(imread, IMREAD_GRAYSCALE) {
+    auto cvImg = cv::imread(img_name, cv::IMREAD_GRAYSCALE);
+    auto mnnImg = imread(img_name, IMREAD_GRAYSCALE);
+    EXPECT_TRUE(testEnv.equal(cvImg, mnnImg));
+}
+
+// imwrite
+TEST(imwrite, jpg) {
+    bool cvRes = cv::imwrite("cv.jpg", testEnv.cvSrc);
+    bool mnnRes = imwrite("mnn.jpg", testEnv.mnnSrc);
+    EXPECT_EQ(cvRes, mnnRes);
+}
+
+#endif