hi_mpi_vpc_calc_hist
The
The
Description
Calculates a histogram of image channels. This API is asynchronous.
Prototype
hi_s32 hi_mpi_vpc_calc_hist(hi_vpc_chn chn, const hi_vpc_pic_info *source_pic, hi_vpc_histogram_config *hist_config, hi_u32 *task_id, hi_s32 milli_sec)
Restrictions
- For input images, the following enum values of hi_pixel_format are supported:
HI_PIXEL_FORMAT_YUV_400 = 0, // YUV400 8bit HI_PIXEL_FORMAT_YUV_SEMIPLANAR_420 = 1, // YUV420SP NV12 8bit HI_PIXEL_FORMAT_YVU_SEMIPLANAR_420 = 2, // YUV420SP NV21 8bit HI_PIXEL_FORMAT_YUV_SEMIPLANAR_422 = 3, // YUV422SP 8bit HI_PIXEL_FORMAT_YVU_SEMIPLANAR_422 = 4, // YVU422SP 8bit HI_PIXEL_FORMAT_YUV_SEMIPLANAR_444 = 5, // YUV444SP 8bit HI_PIXEL_FORMAT_YVU_SEMIPLANAR_444 = 6, // YVU444SP 8bit HI_PIXEL_FORMAT_YUYV_PACKED_422 = 7, // YUV422Packed YUYV 8bit HI_PIXEL_FORMAT_UYVY_PACKED_422 = 8, // YUV422Packed UYVY 8bit HI_PIXEL_FORMAT_YVYU_PACKED_422 = 9, // YUV422Packed YVYU 8bit HI_PIXEL_FORMAT_VYUY_PACKED_422 = 10, // YUV422Packed VYUY 8bit HI_PIXEL_FORMAT_YUV_PACKED_444 = 11, // YUV444P 8bit HI_PIXEL_FORMAT_RGB_888 = 12, // RGB888 HI_PIXEL_FORMAT_BGR_888 = 13, // BGR888 HI_PIXEL_FORMAT_YUV_SEMIPLANAR_440 = 1000, // YUV440SP 8bit HI_PIXEL_FORMAT_YVU_SEMIPLANAR_440 = 1001, // YVU440SP 8bit
- For details about the restrictions on the width and height alignment, buffer size, and image format, see Restrictions on Image Formats, Width and Height Alignment, and Buffers.
Parameters
Parameter |
Input/Output |
Description |
|---|---|---|
chn |
Input |
Channel ID for image processing. |
source_pic |
Input |
Pointer to the input image information.
NOTE:
When the image format is YUV440SP 8-bit or YVU440SP 8-bit, the Y component statistics are accurate, but the UV component statistics are inaccurate. |
hist_config |
Output |
Pointer to the statistics result. hist_config is a struct that contains three arrays, which store the distribution (0–255) of the three components of each image. |
task_id |
Output |
Pointer to the task ID, used to identify a task. |
milli_sec |
Input |
Timeout interval (ms).
|
Returns
- hist_config: result histogram.
- task_id: task ID, used to identify a task.