Absolute Difference
xFabsdiff
function finds the pixel wise absolute difference between two input images and returns an output image. The input and the output images must be the XF_8UC1 type.
Where,
- Iout(x, y) is the intensity of output image at (x,y) position.
- Iin1(x, y) is the intensity of first input image at (x,y) position.
- Iin2(x, y) is the intensity of second input image at (x,y) position.
API Syntax
template void xFabsdiff( xF::Mat src1, xF::Mat src2, xF::Mat dst )
Parameter Descriptions
The following table describes the template and the function parameters.
Parameter | Description |
---|---|
SRC_T | Input pixel type. Only 8-bit, unsigned, 1 channel is supported (XF_8UC1) |
ROWS | Maximum height of input and output image (must be a multiple of 8) |
COLS | Maximum width of input and output image (must be a multiple of 8) |
NPC | Number of pixels to be processed per cycle; possible options are XF_NPPC1 and XF_NPPC8 for 1 pixel and 8 pixel operations respectively. |
src1 | Input image |
src2 | Input image |
dst | Output image |
Resource Utilization
The following table summarizes the resource utilization in different configurations, generated using Vivado® HLS 2017.1 tool for theXilinx Xczu9eg-ffvb1156-1-i-es1FPGA, to process a grayscale HD (1080x1920) image.
Operating Mode | Operating Frequency (MHz) |
Utilization Estimate | ||||
---|---|---|---|---|---|---|
BRAM_18K | DSP_48Es | FF | LUT | CLB | ||
1 pixel | 300 | 0 | 0 | 62 | 67 | 17 |
8 pixel | 150 | 0 | 0 | 67 | 234 | 39 |
Performance Estimate
The following table summarizes the performance in different configurations, as generated usingVivado HLS 2017.1tool for theXilinx Xczu9eg-ffvb1156-1-i-es1, to process a grayscale HD (1080x1920) image.
Operating Mode | Latency Estimate |
---|---|
Max Latency (ms) | |
1 pixel operation (300 MHz) | 6.9 |
8 pixel operation (150 MHz) | 1.69 |
Deviation fromOpenCV
There is no deviation fromOpenCV, except that thexFabsdiff
function supports 8-bit pixels.