The bgr2gray function converts a 3-channel BGR image to GRAY format.
Y= 0.299*R+0.587*G+0.114*B
Where,
- Y = Gray pixel
- R= Red channel
- G= Green channel
- B= Blue channel
API Syntax
template<int SRC_T, int DST_T, int ROWS, int COLS, int NPC=1, int XFCVDEPTH_IN = _XFCVDEPTH_DEFAULT, int XFCVDEPTH_OUT = _XFCVDEPTH_DEFAULT>
void bgr2gray(xf::cv::Mat<SRC_T, ROWS, COLS, NPC, XFCVDEPTH_IN> & _src, xf::cv::Mat<DST_T, ROWS, COLS, NPC, XFCVDEPTH_OUT> & _dst)
Parameter Descriptions
The following table describes the template and the function parameters.
| Parameter | Description |
|---|---|
| SRC_T | Input pixel type. Only 8-bit, unsigned, 3-channel is supported (XF_8UC3). |
| DST_T | Output pixel type. Only 8-bit, unsigned,1-channel is supported (XF_8UC1). |
| ROWS | Maximum height of input and output image. Must be multiple of 8. |
| COLS | Maximum width of input and output image. Must be multiple of 8. |
| NPC | Number of pixels to be processed per cycle. |
| XFCVDEPTH_IN | Depth of input image |
| XFCVDEPTH_OUT | Depth of output image |
| _src | BGR input image |
| _dst | GRAY output image |
Resource Utilization
The following table summarizes the resource utilization of BGR to GRAY for different configurations, as generated in the Vivado HLS 2019.1 version tool for the Xczu9eg-ffvb1156-1-i-es1 FPGA, to process a HD (1080x1920) image.
| Operating Mode | Operating Frequency (MHz) | Utilization Estimate | |||
|---|---|---|---|---|---|
| BRAM_18K | DSP_48Es | FF | LUT | ||
| 1 Pixel | 300 | 0 | 3 | 439 | 280 |
Performance Estimate
The following table summarizes the performance of BGR to GRAY for different configurations, as generated using the Vivado HLS 2019.1 version tool for the Xczu9eg-ffvb1156-1-i-es1, to process a grayscale HD (1080x1920) image.
Table bgr2gray Function Performance Estimate Summary
Operating Mode Latency Estimate Max Latency (ms) 1 pixel operation (300 MHz) 6.9