【OpenVX】vx_Unity3D-终身学习网

1. 官方定义

OpenVX 图像类型 vx_imagee中用vx_imagepatch_addressing_t结构表示数据的内存布局。以下是官方对vx_imagepatch_addressing_t结构的定义与成员解释。英文不好，直接附上原文。

typedef struct _vx_imagepatch_addressing_t {
    vx_uint32    dim_x;
    vx_uint32    dim_y;
    vx_int32     stride_x;
    vx_int32     stride_y;
    vx_uint32    scale_x;
    vx_uint32    scale_y;
    vx_uint32    step_x;
    vx_uint16    step_y;
    vx_uint16    stride_x_bits;
} vx_imagepatch_addressing_t;

dim_x, dim_y
The dimensions of the image in logical pixel units in the x & y direction.
stride_x, stride_y
The physical byte distance from a logical pixel to the next logically adjacent pixel in the positive x or y direction.
scale_x, scale_y
The relationship of scaling from the primary plane (typically the zero indexed plane) to this plane. An integer down-scaling factor of f shall be set to a value equal to scale = unity / f and an integer up-scaling factor of f shall be set to a value of scale = unity × f. unity is defined as VX_SCALE_UNITY.
step_x, step_y
The step is the number of logical pixel units to skip to arrive at the next physically unique pixel. For example, on a plane that is half-scaled in a dimension, the step in that dimension is 2 to indicate that every other pixel in that dimension is an alias. This is useful in situations where iteration over unique pixels is required, such as in serializing or de-serializing the image patch information.
stride_x_bits
The physical bit distance from a logical pixel to the next logically adjacent pixel in the positive x-direction. This field is only used when the stride in the x-direction is not an integer number of bytes (e.g. for VX_DF_IMAGE_U1 images).

2. 辅助函数

获取图像类型的字符串显示

std::string get_string_vx_df_image_e(vx_df_image_e format)
{
    switch (format)
    {
    case VX_DF_IMAGE_VIRT:
        return std::string("VX_DF_IMAGE_VIRT");
    case VX_DF_IMAGE_RGB:
        return std::string("VX_DF_IMAGE_RGB");
    case VX_DF_IMAGE_RGBX:
        return std::string("VX_DF_IMAGE_RGBX");
    case VX_DF_IMAGE_NV12:
        return std::string("VX_DF_IMAGE_NV12");
    case VX_DF_IMAGE_NV21:
        return std::string("VX_DF_IMAGE_NV21");
    case VX_DF_IMAGE_UYVY:
        return std::string("VX_DF_IMAGE_UYVY");
    case VX_DF_IMAGE_YUYV:
        return std::string("VX_DF_IMAGE_YUYV");
    case VX_DF_IMAGE_IYUV:
        return std::string("VX_DF_IMAGE_IYUV");
    case VX_DF_IMAGE_U8:
        return std::string("VX_DF_IMAGE_U8");
    case VX_DF_IMAGE_U16:
        return std::string("VX_DF_IMAGE_U16");
    case VX_DF_IMAGE_S16:
        return std::string("VX_DF_IMAGE_S16");
    case VX_DF_IMAGE_U32:
        return std::string("VX_DF_IMAGE_U32");
    case VX_DF_IMAGE_S32:
        return std::string("VX_DF_IMAGE_S32");
    }

    return std::string("");
}

显示vx_imagepatch_addressing_t成员值

void show_vx_image_patch_addressing_t(vx_image image) {
vx_df_image_e format;
vxQueryImage(image, VX_IMAGE_FORMAT, &format, sizeof(vx_df_image));
std::cout << "format        : " << get_string_vx_df_image_e(format) << std::endl;
vx_size planes;
vxQueryImage(image, VX_IMAGE_PLANES, &planes, sizeof(vx_size));

vx_rectangle_t patch;
vxGetValidRegionImage(image, &patch);

for (size_t i = 0; i < planes; i++) {
    vx_imagepatch_addressing_t addr = VX_IMAGEPATCH_ADDR_INIT;

    vx_map_id map_id;
    unsigned char *ptr;
    vxMapImagePatch(image, &patch, i, &map_id, &addr, (void **) &ptr,
                    VX_READ_ONLY, VX_MEMORY_TYPE_HOST,VX_NOGAP_X);
    std::cout << "tplane        : " << i << std::endl;
    std::cout << "taddr.dim_x   : " << addr.dim_x << std::endl;
    std::cout << "taddr.dim_y   : " << addr.dim_y << std::endl;
    std::cout << "taddr.stride_x: " << addr.stride_x << std::endl;
    std::cout << "taddr.stride_y: " << addr.stride_y << std::endl;
    std::cout << "taddr.scale_x : " << addr.scale_x << std::endl;
    std::cout << "taddr.scale_y : " << addr.scale_y << std::endl;
    std::cout << "taddr.step_x  : " << addr.step_x << std::endl;
    std::cout << "taddr.step_y  : " << addr.step_y << std::endl;
    std::cout << std::endl;
    vxUnmapImagePatch(image, map_id);
}

测试程序

void TEST_image_patch_addr_for_all_types(vx_context context) {
for (auto &df_image : df_images) {
    std::cout << "===================================================" << std::endl;
    vx_image image = vxCreateImage(context, 640, 480, df_image);
    show_vx_image_patch_addressing_t(image);
}

3. 测试程序

相同尺寸不同图像类型
```
int main()
{
    vx_context context = vxCreateContext();
    TEST_image_stride_y(context, 100, 100, VX_DF_IMAGE_U8);
    TEST_image_stride_y(context, 100, 100, VX_DF_IMAGE_RGB);
    TEST_image_stride_y(context, 100, 100, VX_DF_IMAGE_NV12);

    vxReleaseContext(&context);
    return EXIT_SUCCESS;
}
```
===================================================
format :
===================================================
format : VX_DF_IMAGE_RGB
plane : 0
addr.dim_x : 640
addr.dim_y : 480
addr.stride_x: 3
addr.stride_y: 1920
addr.scale_x : 1024
addr.scale_y : 1024
addr.step_x : 1
addr.step_y : 1

===================================================
format : VX_DF_IMAGE_RGBX
plane : 0
addr.dim_x : 640
addr.dim_y : 480
addr.stride_x: 4
addr.stride_y: 2560
addr.scale_x : 1024
addr.scale_y : 1024
addr.step_x : 1
addr.step_y : 1

===================================================
format : VX_DF_IMAGE_NV12
plane : 0
addr.dim_x : 640
addr.dim_y : 480
addr.stride_x: 1
addr.stride_y: 640
addr.scale_x : 1024
addr.scale_y : 1024
addr.step_x : 1
addr.step_y : 1

plane : 1
addr.dim_x : 640
addr.dim_y : 480
addr.stride_x: 2
addr.stride_y: 640
addr.scale_x : 512
addr.scale_y : 512
addr.step_x : 2
addr.step_y : 2

===================================================
format : VX_DF_IMAGE_NV21
plane : 0
addr.dim_x : 640
addr.dim_y : 480
addr.stride_x: 1
addr.stride_y: 640
addr.scale_x : 1024
addr.scale_y : 1024
addr.step_x : 1
addr.step_y : 1

plane : 1
addr.dim_x : 640
addr.dim_y : 480
addr.stride_x: 2
addr.stride_y: 640
addr.scale_x : 512
addr.scale_y : 512
addr.step_x : 2
addr.step_y : 2

===================================================
format : VX_DF_IMAGE_UYVY
plane : 0
addr.dim_x : 640
addr.dim_y : 480
addr.stride_x: 2
addr.stride_y: 1280
addr.scale_x : 1024
addr.scale_y : 1024
addr.step_x : 1
addr.step_y : 1

===================================================
format : VX_DF_IMAGE_YUYV
plane : 0
addr.dim_x : 640
addr.dim_y : 480
addr.stride_x: 2
addr.stride_y: 1280
addr.scale_x : 1024
addr.scale_y : 1024
addr.step_x : 1
addr.step_y : 1

===================================================
format : VX_DF_IMAGE_IYUV
plane : 0
addr.dim_x : 640
addr.dim_y : 480
addr.stride_x: 1
addr.stride_y: 640
addr.scale_x : 1024
addr.scale_y : 1024
addr.step_x : 1
addr.step_y : 1

plane : 1
addr.dim_x : 640
addr.dim_y : 480
addr.stride_x: 1
addr.stride_y: 320
addr.scale_x : 512
addr.scale_y : 512
addr.step_x : 2
addr.step_y : 2

plane : 2
addr.dim_x : 640
addr.dim_y : 480
addr.stride_x: 1
addr.stride_y: 320
addr.scale_x : 512
addr.scale_y : 512
addr.step_x : 2
addr.step_y : 2

===================================================
format : VX_DF_IMAGE_YUV4
plane : 0
addr.dim_x : 640
addr.dim_y : 480
addr.stride_x: 1
addr.stride_y: 640
addr.scale_x : 1024
addr.scale_y : 1024
addr.step_x : 1
addr.step_y : 1

plane : 1
addr.dim_x : 640
addr.dim_y : 480
addr.stride_x: 1
addr.stride_y: 640
addr.scale_x : 1024
addr.scale_y : 1024
addr.step_x : 1
addr.step_y : 1

plane : 2
addr.dim_x : 640
addr.dim_y : 480
addr.stride_x: 1
addr.stride_y: 640
addr.scale_x : 1024
addr.scale_y : 1024
addr.step_x : 1
addr.step_y : 1

===================================================
format : VX_DF_IMAGE_U8
plane : 0
addr.dim_x : 640
addr.dim_y : 480
addr.stride_x: 1
addr.stride_y: 640
addr.scale_x : 1024
addr.scale_y : 1024
addr.step_x : 1
addr.step_y : 1

===================================================
format : VX_DF_IMAGE_U16
plane : 0
addr.dim_x : 640
addr.dim_y : 480
addr.stride_x: 2
addr.stride_y: 1280
addr.scale_x : 1024
addr.scale_y : 1024
addr.step_x : 1
addr.step_y : 1

===================================================
format : VX_DF_IMAGE_S16
plane : 0
addr.dim_x : 640
addr.dim_y : 480
addr.stride_x: 2
addr.stride_y: 1280
addr.scale_x : 1024
addr.scale_y : 1024
addr.step_x : 1
addr.step_y : 1

===================================================
format : VX_DF_IMAGE_U32
plane : 0
addr.dim_x : 640
addr.dim_y : 480
addr.stride_x: 4
addr.stride_y: 2560
addr.scale_x : 1024
addr.scale_y : 1024
addr.step_x : 1
addr.step_y : 1

===================================================
format : VX_DF_IMAGE_S32
plane : 0
addr.dim_x : 640
addr.dim_y : 480
addr.stride_x: 4
addr.stride_y: 2560
addr.scale_x : 1024
addr.scale_y : 1024
addr.step_x : 1
addr.step_y : 1

===================================================
format : VX_DF_IMAGE_U1
plane : 0
addr.dim_x : 640
addr.dim_y : 480
addr.stride_x: 0
addr.stride_y: 80
addr.scale_x : 1024
addr.scale_y : 1024
addr.step_x : 1
addr.step_y : 1

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