hi_mpi_vpc_calc_hist

Applicability

Product	Supported
Atlas A3 training products/Atlas A3 inference products	√
Atlas A2 training products/Atlas A2 inference products	√
Atlas 200I/500 A2 inference products	√
Atlas inference products	√
Atlas training products	☓

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)

Parameters

Parameter	Input/Output	Description
chn	Input	Channel ID for image processing. Atlas A3 training products/Atlas A3 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 inference products: The value range of this parameter is [0, 256). The maximum number of channels is 256.
source_pic	Input	Pointer to the input image information. 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 result histogram. hist_config is a structure 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, which is used to identify a task.
milli_sec	Input	Timeout interval (ms): –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.

Returns

hist_config: result histogram
task_id: task ID, used to identify a task

Restrictions

Requirements on the input resolution:

Model	Input Image Resolution
Atlas inference products	[10 x 6, 4096 x 4096]
Atlas A3 training products/Atlas A3 inference products Atlas A2 training products/Atlas A2 inference products Atlas 200I/500 A2 inference products	[10 x 6, 4096 x 8192]

Model

Input Image Resolution

Atlas inference products

[10 x 6, 4096 x 4096]

Atlas A3 training products/Atlas A3 inference products

Atlas A2 training products/Atlas A2 inference products

Atlas 200I/500 A2 inference products

[10 x 6, 4096 x 8192]

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.

Parent topic: Vision Preprocessing Core (VPC)