• English
  • 3.5.0

    • Filter2d

    Filters (convolves) a 2D image using the specified filter kernel, where the anchor point defaults to the center of the convolution kernel.

    Operator Effect

    Input ImageParameterOutput Image
    imagekernel=[0.003906250.0156250.027343750.0156250.003906250.0156250.06250.10156250.06250.0156250.027343750.10156250.093750.10156250.027343750.0156250.06250.10156250.06250.0156250.003906250.0156250.027343750.0156250.00390625]\begin{aligned}kernel = \begin{bmatrix} 0.00390625& 0.015625& 0.02734375& 0.015625& 0.00390625\\ 0.015625& 0.0625& 0.1015625& 0.0625& 0.015625&\\ 0.02734375& 0.1015625& 0.09375& 0.1015625& 0.02734375\\ 0.015625& 0.0625& 0.1015625& 0.0625& 0.015625\\ 0.00390625& 0.015625& 0.02734375& 0.015625& 0.00390625\end{bmatrix}\end{aligned}
    borderType = HB_VP_BORDER_REPLICATE    		image

    Principle

    dst(x,y)=∑0⩽x′<kernel.cols0⩽y′<kernel.rowskernel(x′,y′)∗src(x+x′−anchor.x,y+y′−anchor.y)\begin{aligned}dst(x,y)=\sum_{\begin{aligned}0\leqslant x'<kernel.cols \\ 0\leqslant y'<kernel.rows \end{aligned}}kernel(x',y')*src(x+x'-anchor.x,y+y'-anchor.y)\end{aligned}

    Among them, dstdst is the output image, kernelkernel is the filter kernel, and anchoranchor is the anchor coordinates, the default anchor is (-1, -1).

    API Interface

    int32_t hbVPFilter2D(hbUCPTaskHandle_t *taskHandle,
                     hbVPImage *dstImg,
                     hbVPImage const *srcImg,
                     hbVPFilterKernel const *filterKernel,
                     hbVPFilter2DParam const *filter2DParam);

    For detailed interface information, please refer to hbVPFilter2D.

    Usage

    // Include the header
#include "hobot/hb_ucp.h"
#include "hobot/vp/hb_vp.h"
#include "hobot/vp/hb_vp_filter2d.h"

// init Image, allocate memory for image data
hbUCPSysMem src_mem;
hbUCPMallocCached(&src_mem, src_stride * src_height, 0);
hbVPImage src_img{HB_VP_IMAGE_FORMAT_Y,
                  HB_VP_IMAGE_TYPE_U8C1,
                  src_width,
                  src_height,
                  src_stride,
                  src_mem.virAddr,
                  src_mem.phyAddr,
                  nullptr,
                  0,
                  0};

hbUCPSysMem dst_mem;
hbUCPMallocCached(&dst_mem, dst_stride * dst_height, 0);
hbVPImage dst_img{HB_VP_IMAGE_FORMAT_Y,
                  HB_VP_IMAGE_TYPE_U8C1,
                  dst_width,
                  dst_height,
                  dst_stride,
                  dst_mem.virAddr,
                  dst_mem.phyAddr,
                  nullptr,
                  0,
                  0};
// init kernel
hbVPFilterKernel kernel;
kernel.dataType = HB_VP_IMAGE_TYPE_F32C1;
kernel.width = 5;
kernel.height = 5;
hbUCPSysMem kernel_mem;
hbUCPMallocCached(&kernel_mem, kernel.width * kernel.height * sizeof(float32_t), 0);
kernel.dataPhyAddr = kernel_mem.phyAddr;
kernel.dataVirAddr = kernel_mem.virAddr;

// init param
hbVPFilter2DParam vp_param;
vp_param.borderType = HB_VP_BORDER_REPLICATE;

// init task handle and schedule param
hbUCPTaskHandle_t task_handle{nullptr};
hbUCPSchedParam sched_param;
HB_UCP_INITIALIZE_SCHED_PARAM(&sched_param);
sched_param.backend = HB_UCP_DSP_CORE_0;

// create task
hbVPFilter2D(&task_handle, &dst_img, &src_img, &kernel, &vp_param);

// submit task
hbUCPSubmitTask(task_handle, &sched_param);

// wait for task done 
hbUCPWaitTaskDone(task_handle, 0);

// release task handle
hbUCPReleaseTask(task_handle);

// release memory
hbUCPFree(&src_mem);
hbUCPFree(&dst_mem);
hbUCPFree(&kernel_mem);