HDR Merge - 2023.2 English

HDR Merge module generates the High Dynamic Range (HDR) image from a set of different exposure frames. Usually, image sensors has limited dynamic range and it’s difficult to get HDR image with single image capture. From the sensor, the frames are collected with different exposure times and will get different exposure frames. HDRMerge will generate the HDR frame with those exposure frames. The HDRMerge in RGB domain is complex and expensive interms of latency, because of camera response function. But,in Bayer domain the camera resonse function is linear. The radiance value which passes through the lens of the image sensor is converted into pixel intensity value. The camera response function relates the radiance value to pixel value. The CRF function in

here,

The CRF function f(x) linearly express as

To compute the weight in pixel value domain,

API Syntax

template <int SRC_T, int DST_T, int ROWS, int COLS, int NPC = 1, int NO_EXPS, int W_SIZE, int XFCVDEPTH_IN_1 = _XFCVDEPTH_DEFAULT, int XFCVDEPTH_IN_2 = _XFCVDEPTH_DEFAULT, int XFCVDEPTH_OUT = _XFCVDEPTH_DEFAULT>
void Hdrmerge_bayer(xf::cv::Mat<SRC_T, ROWS, COLS, NPC, XFCVDEPTH_IN_1>& _src_mat1,
                xf::cv::Mat<SRC_T, ROWS, COLS, NPC, XFCVDEPTH_IN_2>& _src_mat2,
                xf::cv::Mat<SRC_T, ROWS, COLS, NPC, XFCVDEPTH_OUT>& _dst_mat,
                short wr_hls[NO_EXPS * NPC * W_SIZE])

The following table describes the template and the function parameters.

Resource Utilization

The following table summarizes the resource utilization in different configurations, generated using Vitis HLS 2021.1 tool for the xczu9eg-ffvb1156-2-e, to process a bayer HD image.

Performance Estimate

The following table summarizes the latency numbers in different configurations, generated using Vitis HLS 2021.1 tool for the xczu9eg-ffvb1156-2-e, to process a HD image.