ISP Stats - ISP Stats - 2022.2 English

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

API Syntax

template <int MAX_ZONES,
        int STATS_SIZE,
        int FINAL_BINS_NUM,
        int MERGE_BINS,
        int SRC_T,
        int ROWS,
        int COLS,
        int NPC = 1,
        int XFCVDEPTH_IN = _XFCVDEPTH_DEFAULT>
void ispStats(xf::cv::Mat<SRC_T, ROWS, COLS, NPC>& _src,
              uint32_t* stats,
              uint32_t* 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)

Parameter Descriptions

The following table describes the template and the function parameters.

Table 577 Table . ispstats Parameter Description
Parameter	Description
MAX_ZONES	Maximum number of possible zones.
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.
FINAL_BINS_NUM	Number of output bins per channel if merge bins feature is enabled.
MERGE_BINS	To disable or enable merge bins feature.
SRC_T	Input pixel type. For BGR, 8UC3 is supported as input. For Bayer, 8UC1 is supported
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	Calculted 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.

Resource Utilization

The following table summarizes the resource utilization in different configurations, generated using Vitis HLS 2022.1 tool for the Alveo U50 FPGA.

Table 578 Table . ispstats Function Resource Utilization Summary
Operating Mode	Operating Frequency (MHz)	Input pattern	MEGRE BINS	Utilization Estimate
Operating Mode	Operating Frequency (MHz)	Input pattern	MEGRE BINS	BRAM_18K	DSP_48Es	FF	LUT
1 Pixel	150	BGR 8-bit/channel	0	144	4	6011	34828
1 Pixel	150	BGR 8-bit/channel	1	144	4	5933	36231
1 Pixel	150	BGR 8-bit/channel	1	144	4	5933	36231

Performance Estimate

The following table summarizes the performance of the kernel in 1-pixel mode as generated using Vitis HLS 2022.1 tool for the Xilinx Alveo U50 FPGA to process a grayscale HD (1920x1080) image.

Table 579 Table . rgbir2bayer 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	16.8
1 pixel operation (150 MHz)	BGR 8-bit/channel	1	20.3