vpc_calc_hist_v2

Applicability

Product	Supported (√/x)
Atlas A3 training products/Atlas A3 inference products	√
Atlas A2 training products/Atlas A2 inference products	√
Atlas training products	x
Atlas inference products	√
Atlas 200I/500 A2 inference products	√

Function Usage

Calculates a histogram of image channels. This API is asynchronous.

Prototype

C 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);

Python Function

task_id, ret = acl.himpi.vpc_calc_hist_v2(chn, source_pic, milli_sec, hist_config)

Parameter Description

Parameter	Description
chn	Int, channel ID for image processing. Atlas inference products: The value range of this parameter is [0, 256). The maximum number of channels is 256. Atlas A2 training products/Atlas A2 inference products: The value range of this parameter is [0, 256). The maximum number of channels is 256. Atlas 200I/500 A2 inference products: The value range of this parameter is [0, 128). The maximum number of channels is 128. Atlas A3 training products/Atlas A3 inference products: The value range of this parameter is [0, 256). The maximum number of channels is 256.
source_pic	Dict. Input image information. For details, see hi_vpc_pic_info. For details about related restrictions, see Restrictions. NOTE: When the image format is 8-bit YUV440SP or 8-bit YVU440SP, the Y component statistics are accurate, but the UV component statistics are inaccurate.
milli_sec	Int, timeout interval, in milliseconds. -1: blocking mode. 0: non-blocking mode. > 0: timeout interval (timeout mode). The timeout interval varies with the operating system. The deviation is generally within a time slice of an operating system. For example, if the time slice of an operating system is 4 ms and the value of milli_sec is set to 1, the actual timeout interval ranges from 1 ms to 5 ms. When the CPU load is high, the timeout interval may fluctuate.
hist_config	Int, pointer address of the statistics result. The address in hist_config points to the struct that contains the statistics result and stores the distribution (0–255) of the three components of each image. np_out_size = np.array([out_buffer_size], dtype=np.int32) is called to create data of a NumPy array. Then bytes_data = np_out_size.tobytes()-> \->size_ptr = acl.util.bytes_to_ptr(bytes_data) is called to convert the data into an object as the argument. After the function is called successfully, the data (np_out_size) converted by size_ptr changes.

Return Value Description

Return Value	Description
task_id	Int, task ID, used to identify a task.
ret	Int, error code. 0: success. Other values: failures. For details, see VPC Return Codes.

Restrictions

Requirements on the input resolution:

Version	Restriction
Atlas inference products	Input image resolution: [10 x 6, 4096 x 4096].
Atlas 200I/500 A2 inference products Atlas A2 training products/Atlas A2 inference products Atlas A3 training products/Atlas A3 inference products	Input image resolution: [10 x 6, 4096 x 8192].

Version

Restriction

Atlas inference products

Input image resolution: [10 x 6, 4096 x 4096].

Atlas 200I/500 A2 inference products

Atlas A2 training products/Atlas A2 inference products

Atlas A3 training products/Atlas A3 inference products

Input image resolution: [10 x 6, 4096 x 8192].

The following enum values of hi_pixel_format are supported for the source image format:

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.

Parent topic: VPC APIs