Image Statistics IP
DPC Statistics IP implements the computationally intensive metering functionality common in digital cameras, camcorders and imaging devices. This core generates a set of statistics for color histograms on the frame. The statistical information collected may be used in the control algorithms for Auto-Focus, Auto-White Balance, and Auto-Exposure for image processing applications.
The ip receives an video stream, the histogram is calculated in the YCbCr or RGB space. Other statistics are the maximum value, the minimum value and the average.
Interface
The Statistics core uses industry standard control and data interfaces to connect to other system components. The following sections describe the various interfaces available with the core. The Figure below illustrates an I/O diagram of the IP. Some signals are optional and not present for all configurations of the core.
Notice how the module requires two clocks for its operation. It is in fact customary that the configuration clock that drives the AXI4-lite configuration bus has lower frequency than the video stream clock. This simplifies the synthesis and placement of the component. The table below summarizes the meaning of every signal.
| Signal / Bus Name | Direction | Description |
| s_axi_BUS_A | Slave | AXI-Lite Bus for the configuration of IP. |
| inter_pix | Slave | AXI4-Stream Bus for input stream. |
| ap_clk | In | Input Clock for streaming domain. |
| ap_rst_n | In | Low reset synchronized with streaming clock. |
| s_axi_clk | In | Input clock for axilite domain. |
| ap_rst_n_s_axi_clk | In | Low reset synchronized with axilite clock. |
| out_pix | Master | AXI4-Stream Bus for output stream. |
| interrupt | Out | Signal indicating the end of the task. |