Thresholding - 2024.1 English

Vitis Libraries

Release Date
2024-05-30
Version
2024.1 English

The Threshold function performs thresholding operation on the input image. There are several types of thresholding supported by the function.

API Syntax

template<int THRESHOLD_TYPE, int SRC_T, int ROWS, int COLS,int NPC=1, int XFCVDEPTH_IN = _XFCVDEPTH_DEFAULT, int XFCVDEPTH_OUT = _XFCVDEPTH_DEFAULT>
void Threshold(xf::cv::Mat<SRC_T, ROWS, COLS, NPC, XFCVDEPTH_IN> & _src_mat,xf::cv::Mat<SRC_T, ROWS, COLS, NPC, XFCVDEPTH_OUT> & _dst_mat,short int thresh,short int maxval )

Parameter Descriptions

The following table describes the template and the function parameters.

Table 753 Table . Threshold Parameter Description
Parameter Description
THRESHOLD_TY PE Type of thresholding.
SRC_T Input pixel type. Only 8-bit, unsigned, 1 channel is supported (XF_8UC1).
ROWS Maximum height of input and output image.
COLS Maximum width of input and output image. Must be multiple of 8, for 8-pixel operation.
NPC Number of pixels to be processed per cycle.
XFCVDEPTH_IN Depth of the input image.
XFCVDEPTH_OUT Depth of the output image.
_src_mat Input image
_dst_mat Output image
thresh Threshold value.
maxval Maximum value to use with the THRESH_BINARY and THRESH_BINARY_INV thresholding types.

Resource Utilization

The following table summarizes the resource utilization of the kernel with binary thresholding in different configurations, generated using Vivado HLS 2019.1 tool for the Xilinx Xczu9eg-ffvb1156-1 FPGA, to process a grayscale HD (1080x1920) image.

Table 754 Table . Threshold Function Resource Utilization Summary
Name Resource Utilization
1 pixel per clock operation 8 pixel per clock operation
300 MHz 150 MHz
BRAM_18K 0 0
DSP48E 0 0
FF 110 154
LUT 61 139
CLB 16 37

Performance Estimate

The following table summarizes the performance of the kernel in different configurations, as generated using Vivado HLS 2019.1 tool for the Xilinx Xczu9eg-ffvb1156-1, to process a grayscale HD (1080x1920) image.

Table 755 Table . Threshold Function Performance Estimate Summary
Operating Mode

Operating Frequency

(MHz)

Latency Estimate

(ms)

1 pixel 300 7.2
8 pixel 150 1.7