ISP Stats - 2023.2 English

The ispstats function returns histogram of the input BAYER, BGR or GRAY image.

API Syntax

template <
    int MAX_ZONES,
    int STATS_SIZE,
    int FINAL_BINS_NUM,
    int MERGE_BINS,
    int SRC_T,
    int NUM_OUT_CH,
    int ROWS,
    int COLS,
    int NPC = 1,
    int XFCVDEPTH_IN = _XFCVDEPTH_DEFAULT>
void ispStats(
    xf::cv::Mat<SRC_T, ROWS, COLS, NPC, XFCVDEPTH_IN>& _src,
    uint32_t* stats,
    ap_uint<13>* max_bins_list,
    uint16_t roi_tlx,
    uint16_t roi_tly,
    uint16_t roi_brx,
    uint16_t roi_bry,
    uint16_t zone_col_num,
    uint16_t zone_row_num,
    float inputMin,
    float inputMax,
    float outputMin,
    float outputMax
    )

Parameter Descriptions

The following table describes the template and the function parameters.

Table 609 Table . ispstats Parameter Description
Parameter	Description
MAX_ZONES	Maximum number of possible zones. Possible value is 64.
STATS_SIZE	Number of bins per channel for the input image. This is equal to the number of output bins if merge bins feature is disabled. Possible value is 256 and 4096.
FINAL_BINS_NUM	Number of output bins per channel if merge bins feature is enabled. Possible value is 4.
MERGE_BINS	To disable or enable merge bins feature. Possible values are 0 and 1.
SRC_T	Input pixel type. Possible values are XF_8UC3, XF_16UC3, XF_8UC1, XF_16UC1.
NUM_OUT_CH	Number of output channels. Possible Values are 1 and 3.
ROWS	Maximum height of input image.
COLS	Maximum width of input image.
NPC	Number of pixels to be processed per cycle. Possible options are XF_NPPC1 only.
XFCVDEPTH_IN	Depth of Input image
_src	Input image
stats	Calculated histogram of the image.
max_bins_list	List of maximum values per range of bins. This is only applicable if merge bins feature is enabled.
roi_tlx	Top left x coordinate of ROI
roi_tly	Top left y coordinate of ROI
roi_brx	Bottom right x coordinate of ROI
roi_bry	Bottom right y coordinate of ROI
zone_col_num	Number of zones across column.
zone_row_num	Number of zones across rows.
inputMin	Input image range minimum value.
inputMax	Input image range maximum value.
outputMin	Output image range minimum value.
outputMax	Output image range maximum value.

Resource Utilization

The following table summarizes the resource utilization in different configurations, generated using Vitis HLS 2023.1 tool for the zcu102 FPGA.

Table 610 Table . ispstats Function Resource Utilization Summary
Operating Mode	Operating Frequency (MHz)	Input pattern	MERGE BINS	Utilization Estimate
Operating Mode	Operating Frequency (MHz)	Input pattern	MERGE BINS	BRAM_36K	DSPs	CLB Registers	CLB LUTs
1 Pixel	150	BGR 8-bit/channel	0	44.5	13	5692	5120
1 Pixel	150	BGR 16-bit/channel	0	769	16	6559	6218
1 Pixel	150	BGR 8-bit/channel	1	44.5	13	5352	4974
1 Pixel	150	BGR 16-bit/channel	1	769	16	6158	6225

Performance Estimate

The following table summarizes the performance of the kernel in 1-pixel mode as generated using Vitis HLS 2023.1 tool for the Xilinx zcu102 FPGA to process a BGR FHD (1920x1080) image.

Table 611 Table . ispstats Function Performance Estimate Summary
Operating Mode	Input pattern	MERGE BINS	Latency Estimate
Operating Mode	Input pattern	MERGE BINS	Max Latency (ms)
1 pixel operation (150 MHz)	BGR 8-bit/channel	0	14.68
1 pixel operation (150 MHz)	BGR 16-bit/channel	0	21.2514
1 pixel operation (150 MHz)	BGR 8-bit/channel	1	14.7883
1 pixel operation (150 MHz)	BGR 16-bit/channel	1	21.37