Accumulate
xFaccumulatefunction adds an image (src1) to the accumulator image (src2), and generates the accumulated result image (dst).
API Syntax
template void xFaccumulate ( 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) |
| DST_T | Output pixel type. Only 16-bit, unsigned, 1 channel is supported (XF_16UC1) |
| 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 usingVivado HLS 2017.1tool for theXilinx Xczu9eg-ffvb1156-1-i-es1, to process a grayscale HD (1080x1920) image.
| Operating Mode | Operating Frequency (MHz) |
Utilization Estimate | ||||
|---|---|---|---|---|---|---|
| BRAM_18K | DSP_48E | FF | LUT | CLB | ||
| 1 pixel | 300 | 0 | 0 | 62 | 55 | 12 |
| 8 pixel | 150 | 0 | 0 | 389 | 285 | 61 |
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) | 1.7 |
Deviation fromOpenCV
In OpenCVthe accumulated image is stored in the second input image. The src2 image acts as both input and output, as shown below:
Whereas, in thexfOpenCVimplementation, the accumulated image is stored separately, as shown below:
