Remap - 2024.1 English

The remap function takes pixels from one place in the image and relocates them to another position in another image. Two types of interpolation methods are used here for mapping the image from source to destination image.

API Syntax

template<int WIN_ROWS,int INTERPOLATION_TYPE, int SRC_T, int MAP_T, int DST_T, int ROWS, int COLS, int NPC = 1, bool USE_URAM=false, int XFCVDEPTH_IN = _XFCVDEPTH_DEFAULT, int XFCVDEPTH_Remapped = _XFCVDEPTH_DEFAULT, int XFCVDEPTH_MAPX = _XFCVDEPTH_DEFAULT, int XFCVDEPTH_MAPY = _XFCVDEPTH_DEFAULT>

void remap (xf::cv::Mat<SRC_T, ROWS, COLS, NPC, XFCVDEPTH_IN> &_src_mat,
         xf::cv::Mat<DST_T, ROWS, COLS, NPC, XFCVDEPTH_Remapped> &_remapped_mat,
         xf::cv::Mat<MAP_T, ROWS, COLS, NPC, XFCVDEPTH_MAPX> &_mapx_mat,
         xf::cv::Mat<MAP_T, ROWS, COLS, NPC, XFCVDEPTH_MAPY> &_mapy_mat);

Parameter Descriptions

The following table describes the template parameters.

Table 705 Table . remap Parameter Descriptions
Parameter	Description
WIN_ROWS	Number of input image rows to be buffered inside. Must be set based on the map data. For instance, for left right flip, 2 rows are sufficient.
INTERPOLATIO N_TYPE	Type of interpolation, either XF_INTERPOLATION_NN (nearest neighbor) or XF_INTERPOLATION_BILINEAR (linear interpolation)
SRC_T	Input image pixel type. Only 8-bit, unsigned, 1 and 3 channels are supported (XF_8UC1 and XF_8UC3)
MAP_T	Map type. Single channel float type. XF_32FC1.
DST_T	Output image pixel type. Only 8-bit, unsigned, 1 and 3 channels are supported (XF_8UC1 and XF_8UC3)
ROWS	Height of input and output images
COLS	Width of input and output images
NPC	Number of pixels to be processed per cycle; this function supports only XF_NPPC1 or 1 pixel per cycle operations.
USE_URAM	Enable to map some structures to UltraRAM instead of BRAM.
XFCVDEPTH_IN	Depth of the input image.
XFCVDEPTH_Remapped	Depth of the output image.
XFCVDEPTH_MAPX	Depth of the input image.
XFCVDEPTH_MAPY	Depth of the output image.

The following table describes the function parameters.

Table 706 Table . remap Parameter Description
PARAMETERS	DESCRIPTION
_src_mat	Input xF Mat
_remapped_m at	Output xF Mat
_mapx_mat	mapX Mat of float type
_mapy_mat	mapY Mat of float type

Resource Utilization

The following table summarizes the resource utilization of remap, for HD (1080x1920) images generated in the Vivado HLS 2019.1 version tool for the Xilinx xczu9eg-ffvb1156-i-es1 FPGA at 300 MHz, with WIN_ROWS as 64 for the XF_INTERPOLATION_BILINEAR mode.

Table 707 Table . remap Function Resource Utilization Summary
Name	Resource Utilization
BRAM_18K	64
DSP48E	17
FF	1738
LUT	1593
CLB	360

The following table summarizes the resource utilization of remap, for 4K (3840x2160) images generated in the Vivado HLS 2019.1 version tool for the Xilinx xczu7ev-ffvc1156 FPGA at 300 MHz, with WIN_ROWS as 100 for the XF_INTERPOLATION_BILINEAR mode using UltraRAM .

Table 708 Table . remap Function Resource Utilization Summary with UltraRAM Enabled
Name	Resource Utilization
BRAM_18K	3
DSP48E	10
URAM	24
FF	3196
LUT	3705

Performance Estimate

The following table summarizes the performance of remap(), for HD (1080x1920) images generated in the Vivado HLS 2019.1 version tool for the Xilinx xczu9eg-ffvb1156-i-es1 FPGA at 300 MHz, with WIN_ROWS as 64 for XF_INTERPOLATION_BILINEAR mode.

Table 709 Table . remap Function Performance Estimate Summary
Operating Mode	Operating Frequency (MHz)	Latency Estimate Max latency (ms)
1 pixel mode	300	7.2