feat(mgb/opr): add bgr2gray mode for cvtcolor opr

GitOrigin-RevId: d50415b236080a13d31c43158f9d03e2aef48d59

dnn/src/arm_common/cvt_color/opr_impl.cpp

@@ -748,11 +748,16 @@ void cvt_BT601_yuv_transform(const Mat8u& src, Mat8u& dst) {
 
 }  // namespace
 
+template<bool rgb = true>
 void cvt_rgb2gray_32f_neon(const Mat32f& src, Mat32f& dst) {
     static const float coef[] = {0.299f, 0.587f, 0.114f};
     // load coef into neon types
-    const float32x4_t v_cr(vdupq_n_f32(coef[0])), v_cg(vdupq_n_f32(coef[1])),
-            v_cb(vdupq_n_f32(coef[2]));
+    float coef_c0 = rgb ? coef[0] : coef[2];
+    float coef_c1 = coef[1];
+    float coef_c2 = rgb ? coef[2] : coef[0];
+
+    const float32x4_t v_cr(vdupq_n_f32(coef_c0)), v_cg(vdupq_n_f32(coef_c1)),
+            v_cb(vdupq_n_f32(coef_c2));
 
 #define EXPAND(offset)                                                         \
     v_src = vld3q_f32(psrc + offset * 3);                                      \
@@ -796,7 +801,7 @@ void cvt_rgb2gray_32f_neon(const Mat32f& src, Mat32f& dst) {
         }
         // loop over left pixels
         for (; psrc < pend; psrc += 3, pdst += 1) {
-            *pdst = psrc[0] * coef[0] + psrc[1] * coef[1] + psrc[2] * coef[2];
+            *pdst = psrc[0] * coef_c0 + psrc[1] * coef_c1 + psrc[2] * coef_c2;
         }
     }
 #undef EXPAND
@@ -1187,7 +1192,7 @@ void cvt_rgb2gray<float>(const Mat32f& src, Mat32f& dst) {
     megdnn_assert(src.rows() == dst.rows());
     megdnn_assert(src.cols() == dst.cols());
 
-    return cvt_rgb2gray_32f_neon(src, dst);
+    return cvt_rgb2gray_32f_neon<true>(src, dst);
 }
 
 // gray2rgb
@@ -1381,6 +1386,16 @@ void cvt_bgr2gray<uchar>(const Mat8u& src, Mat8u& dst) {
     }
 }
 
+template <>
+void cvt_bgr2gray<float>(const Mat32f& src, Mat32f& dst) {
+    megdnn_assert(src.channels() == 3);
+    megdnn_assert(dst.channels() == 1);
+    megdnn_assert(src.rows() == dst.rows());
+    megdnn_assert(src.cols() == dst.cols());
+
+    return cvt_rgb2gray_32f_neon<false>(src, dst);
+}
+
 template <>
 void cvt_bgr2rgb<uchar>(const Mat8u& src, Mat8u& dst) {
     return cvt_rgb2bgr<uchar>(src, dst);

dnn/src/common/cv/cvt_color.h

@@ -45,7 +45,6 @@
     _cb(cvt_rgba2bgr, float) \
     _cb(cvt_rgba2gray, float) \
     _cb(cvt_rgb2bgr, float) \
-    _cb(cvt_bgr2gray, float) \
     _cb(cvt_bgr2rgb, float) \
     _cb(cvt_yuv2gray_nv21, float) \
     _cb(cvt_yuv2rgb_nv21, float) \

dnn/src/cuda/cvt_color/cvt_color.cu

@@ -145,6 +145,73 @@ __global__ void cvt_rgb2gray_32f_kernel(const float* src, float* dst,
     }
 }
 
+
+__global__ void cvt_bgr2gray_8u_kernel(const uchar* src, uchar* dst,
+                                       const size_t rows, const size_t cols,
+                                       const size_t src_step,
+                                       const size_t dst_step) {
+    size_t t = blockIdx.x * blockDim.x + threadIdx.x;
+
+    if (t < (rows * cols) / U8_PROCESS_PER_THREADS_X) {
+        size_t offset = t * U8_PROCESS_PER_THREADS_X;
+        src += 3 * offset;
+        dst += 1 * offset;
+
+        uchar temp_des[4];
+        uchar temp_src[12];
+        *((uint3*)temp_src) = *((uint3*)src);
+
+        temp_des[0] = (temp_src[0] * 1868 + temp_src[1] * 9617 +
+                       temp_src[2] * 4899 + (1 << 13)) >>
+                      14;
+        temp_des[1] = (temp_src[3] * 1868 + temp_src[4] * 9617 +
+                       temp_src[5] * 4899 + (1 << 13)) >>
+                      14;
+        temp_des[2] = (temp_src[6] * 1868 + temp_src[7] * 9617 +
+                       temp_src[8] * 4899 + (1 << 13)) >>
+                      14;
+        temp_des[3] = (temp_src[9] * 1868 + temp_src[10] * 9617 +
+                       temp_src[11] * 4899 + (1 << 13)) >>
+                      14;
+
+        *((uint32_t*)dst) = *((uint32_t*)temp_des);
+    } else if (t == (rows * cols) / U8_PROCESS_PER_THREADS_X) {
+        size_t rest = (rows * cols) % U8_PROCESS_PER_THREADS_X;
+        if (rest != 0) {
+            size_t offset = t * U8_PROCESS_PER_THREADS_X;
+            src += 3 * offset;
+            dst += 1 * offset;
+
+            for (int i = 0; i < rest; i++, src += 3, dst += 1)
+                dst[0] = (src[0] * 1868 + src[1] * 9617 + src[2] * 4899 +
+                          (1 << 13)) >>
+                         14;
+        }
+    }
+}
+
+__global__ void cvt_bgr2gray_32f_kernel(const float* src, float* dst,
+                                        const size_t rows, const size_t cols,
+                                        const size_t src_step,
+                                        const size_t dst_step) {
+    size_t t = blockIdx.x * blockDim.x + threadIdx.x;
+
+    if (t < rows * cols) {
+        size_t offset = t;
+        src += offset * 3;
+        dst += offset * 1;
+
+        float temp_src[3], temp_dst;
+        *((float3*)temp_src) = *((float3*)src);
+
+        temp_dst = temp_src[0] * 0.114f + temp_src[1] * 0.587f +
+                   temp_src[2] * 0.299f;
+
+        dst[0] = temp_dst;
+    }
+}
+
+
 __global__ void cvt_gray2rgb_8u_kernel(const uchar* src, uchar* dst,
                                        const size_t rows, const size_t cols,
                                        const size_t src_step,
@@ -683,6 +750,9 @@ void cvt_color_8u_proxy(const uchar* src, uchar* dst, const size_t src_rows,
         case CvtColor::Mode::RGB2GRAY:
             CALL_CVT_OPR_8U_KERNEL(rgb2gray)
             break;
+        case CvtColor::Mode::BGR2GRAY:
+            CALL_CVT_OPR_8U_KERNEL(bgr2gray)
+            break;
         case CvtColor::Mode::RGB2YUV:
             CALL_CVT_OPR_8U_KERNEL(rgb2yuv)
             break;
@@ -739,6 +809,9 @@ void cvt_color_32f_proxy(const float* src, float* dst, const size_t src_rows,
         case CvtColor::Mode::RGB2GRAY:
             CALL_CVT_OPR_32F_KERNEL(rgb2gray)
             break;
+        case CvtColor::Mode::BGR2GRAY:
+            CALL_CVT_OPR_32F_KERNEL(bgr2gray)
+            break;
         case CvtColor::Mode::RGB2YUV:
             CALL_CVT_OPR_32F_KERNEL(rgb2yuv)
             break;

dnn/src/naive/cvt_color/opr_impl.cpp

@@ -684,6 +684,26 @@ void cvt_bgr2gray<uchar>(const Mat8u& src, Mat8u& dst) {
     }
 }
 
+template <>
+void cvt_bgr2gray<float>(const Mat32f& src, Mat32f& dst) {
+    megdnn_assert(src.channels() == 3);
+    megdnn_assert(dst.channels() == 1);
+    megdnn_assert(src.rows() == dst.rows());
+    megdnn_assert(src.cols() == dst.cols());
+
+    const float coef_r = 0.299f, coef_g = 0.587f, coef_b = 0.114f;
+    for (size_t r = 0; r < src.rows(); ++r) {
+        for (size_t c = 0; c < src.cols(); ++c) {
+            float B = src.at(r, c, 0);
+            float G = src.at(r, c, 1);
+            float R = src.at(r, c, 2);
+            float& Y = dst.at(r, c, 0);
+            Y = R * coef_r + G * coef_g + B * coef_b;
+        }
+    }
+}
+
+
 template <>
 void cvt_bgr2rgb<uchar>(const Mat8u& src, Mat8u& dst) {
     return cvt_rgb2bgr<uchar>(src, dst);

dnn/src/x86/cvt_color/opr_impl.cpp

@@ -1311,6 +1311,41 @@ void cvt_rgb2gray_32f_SSE_4_2(const Mat32f& src, Mat32f& dst) {
     }
 }
 
+MEGDNN_ATTRIBUTE_TARGET("sse4.2")
+void cvt_bgr2gray_32f_SSE_4_2(const Mat32f& src, Mat32f& dst) {
+    const float coef_r = 0.299f, coef_g = 0.587f, coef_b = 0.114f;
+    __m128 v_coef_r = _mm_set1_ps(coef_r);
+    __m128 v_coef_g = _mm_set1_ps(coef_g);
+    __m128 v_coef_b = _mm_set1_ps(coef_b);
+
+    for (size_t r = 0; r < src.rows(); ++r) {
+        const float* psrc = src.ptr(r);
+        float* pdst = dst.ptr(r);
+        const float* const pend = psrc + src.cols() * 3;
+        __m128 v_r, v_g, v_b, ans;
+        for (; psrc <= pend - 4 * 3; psrc += 4 * 3, pdst += 4) {
+            v_b = _mm_set_ps(psrc[9], psrc[6], psrc[3], psrc[0]);
+            v_b = _mm_mul_ps(v_b, v_coef_b);
+
+            v_g = _mm_set_ps(psrc[10], psrc[7], psrc[4], psrc[1]);
+            v_g = _mm_mul_ps(v_g, v_coef_g);
+
+            v_r = _mm_set_ps(psrc[11], psrc[8], psrc[5], psrc[2]);
+            v_r = _mm_mul_ps(v_r, v_coef_r);
+
+            ans = _mm_add_ps(v_r, _mm_add_ps(v_g, v_b));
+
+            _mm_storeu_ps(pdst, ans);
+        }
+
+        for (; psrc < pend; psrc += 3, pdst += 1) {
+            pdst[0] = psrc[1] * coef_g + psrc[0] * coef_b + psrc[2] * coef_r;
+        }
+    }
+}
+
+
+
 MEGDNN_ATTRIBUTE_TARGET("sse4.2")
 void cvt_rgba2rgb_8u_SSE_4_2(const Mat8u& src, Mat8u& dst) {
     __m128i dst_data0, dst_data1, dst_data2;
@@ -1705,6 +1740,16 @@ void cvt_bgr2gray<uchar>(const Mat8u& src, Mat8u& dst) {
     }
 }
 
+template <>
+void cvt_bgr2gray<float>(const Mat32f& src, Mat32f& dst) {
+    megdnn_assert(src.channels() == 3);
+    megdnn_assert(dst.channels() == 1);
+    megdnn_assert(src.rows() == dst.rows());
+    megdnn_assert(src.cols() == dst.cols());
+
+    return cvt_bgr2gray_32f_SSE_4_2(src, dst);
+}
+
 template <>
 void cvt_bgr2rgb<uchar>(const Mat8u& src, Mat8u& dst) {
     return cvt_rgb2bgr<uchar>(src, dst);

dnn/test/common/cvt_color.h

@@ -133,6 +133,9 @@ inline std::vector<TestArg> get_cuda_args() {
     for (size_t i = 2; i <= 10; ++i) {
         for (size_t j = 2; j <= 10; ++j) {
             cur_param.mode = Mode::RGB2GRAY;
+            args.emplace_back(cur_param, TensorShape{1, i, j, 3},
+                              dtype::Uint8());
+            cur_param.mode = Mode::BGR2GRAY;
             args.emplace_back(cur_param, TensorShape{1, i, j, 3},
                               dtype::Uint8());
             cur_param.mode = Mode::RGB2YUV;
@@ -146,6 +149,9 @@ inline std::vector<TestArg> get_cuda_args() {
                               dtype::Uint8());
             // float32 test
             cur_param.mode = Mode::RGB2GRAY;
+            args.emplace_back(cur_param, TensorShape{1, i, j, 3},
+                              dtype::Float32());
+            cur_param.mode = Mode::BGR2GRAY;
             args.emplace_back(cur_param, TensorShape{1, i, j, 3},
                               dtype::Float32());
             cur_param.mode = Mode::RGB2YUV;

imperative/python/test/unit/functional/test_functional.py

@@ -1057,12 +1057,19 @@ def test_cvt_color():
     def rgb2gray(rgb):
         return np.dot(rgb[..., :3], [0.299, 0.587, 0.114])
 
+    def bgr2gray(bgr):
+        return np.dot(bgr[..., :3], [0.114, 0.587, 0.299])
+
     inp = np.random.randn(3, 3, 3, 3).astype(np.float32)
     out = np.expand_dims(rgb2gray(inp), 3).astype(np.float32)
     x = tensor(inp)
     y = F.vision.cvt_color(x, mode="RGB2GRAY")
     np.testing.assert_allclose(y.numpy(), out, atol=1e-5)
 
+    out1 = np.expand_dims(bgr2gray(inp), 3).astype(np.float32)
+    y1 = F.vision.cvt_color(x, mode="BGR2GRAY")
+    np.testing.assert_allclose(y1.numpy(), out1, atol=1e-5)
+
 
 @pytest.mark.parametrize("val", [2, [2,], [2, 3]])
 def test_ones(val):