**• Hardware Platform (Jetson / GPU)**Jetson
• DeepStream Version6.1.1
Dear all,I am trying to apply edgedetection to detected object of each frame.Here is my codes:
static GstPadProbeReturn
gie_processing_done_buf_prob (GstPad * pad, GstPadProbeInfo * info,
gpointer u_data)
{
GstBuffer *buf = (GstBuffer *) info->data;
NvDsInstanceBin *bin = (NvDsInstanceBin *) u_data;
guint index = bin->index;
AppCtx *appCtx = bin->appCtx;
//extra
NvDsBatchMeta *batch_meta = gst_buffer_get_nvds_batch_meta(buf);
// Get original raw data
GstMapInfo in_map_info;
g_mutex_lock(&buffer_lock);
gst_buffer_map (buf, &in_map_info, GST_MAP_READ);
NvBufSurface *surface = (NvBufSurface *)in_map_info.data;
for (NvDsMetaList * l_frame = batch_meta->frame_meta_list; l_frame != NULL;
l_frame = l_frame->next) {
NvDsFrameMeta *frame_meta = l_frame->data;
//TODO for cuda device memory we need to use cudamemcpy
NvBufSurfaceMap (surface, -1, -1, NVBUF_MAP_READ);
/* Cache the mapped data for CPU access */
NvBufSurfaceSyncForCpu (surface, 0, 0); //will do nothing for unified memory type on dGPU
guint height = surface->surfaceList[frame_meta->batch_id].height;
guint width = surface->surfaceList[frame_meta->batch_id].width;
float angle;
edgedetection(height,width,surface,frame_meta,angle);
}
NvBufSurfaceUnMap(surface,0,0);
gst_buffer_unmap (buf, &in_map_info);
g_mutex_unlock(&buffer_lock);
if (gst_buffer_is_writable (buf))
process_buffer (buf, appCtx, index);
return GST_PAD_PROBE_OK;
}
For edgedetection function,it is defined in another cpp file:
//custom function
void edgedetection(guint height,guint width,NvBufSurface *surface,NvDsFrameMeta *frame_meta,float angle){
Mat nv12_mat = Mat(height*3/2, width, CV_8UC1, surface->surfaceList[frame_meta->batch_id].mappedAddr.addr[0],
surface->surfaceList[frame_meta->batch_id].pitch);
for (NvDsMetaList * l_obj = frame_meta->obj_meta_list; l_obj != NULL;
l_obj = l_obj->next) {
NvDsObjectMeta *obj = (NvDsObjectMeta *) l_obj->data;
Rect bbox(obj->rect_params.left, obj->rect_params.top,
obj->rect_params.width, obj->rect_params.height);
Mat imgray;
cvtColor(nv12_mat, imgray, COLOR_YUV2GRAY_NV12);
// 确保 bbox 的宽度和高度是有效的
if (bbox.width > 0 && bbox.height > 0) {
Mat roi = imgray(bbox);
Mat edges;
Canny(roi, edges, 100, 200,3);
Mat thresh;
threshold(edges, thresh, 127, 255, THRESH_BINARY);
std::vector<std::vector<Point>> contours;
std::vector<Vec4i> hierarchy;
findContours(thresh, contours, hierarchy, RETR_EXTERNAL, CHAIN_APPROX_SIMPLE);
bool found_ellipse=false;
for (const auto& cnt : contours) {
if (cnt.size() > 100) {
RotatedRect ellipse_rect=fitEllipse(cnt);
}
angle=ellipse_rect.angle;
cout << "角度是： " << std::fixed<<std::setprecision(2)<<angle <<endl;
break;
}
}
obj->misc_obj_info[0]=angle;
}
}
Besides,in order to see the angle on the screen,I print it on the text in process_meta() function:
//add angle
float angle=obj->misc_obj_info[0];
sprintf (str_ins_pos, ",%.2f",angle);
str_ins_pos += strlen (str_ins_pos);
Thats’s all,my problem is,I can’t get the really angle of detected object when I apply edgedetection.
I suspect that it may be image resolution problem.I mean that:
Rect bbox(obj->rect_params.left, obj->rect_params.top,
obj->rect_params.width, obj->rect_params.height);
What is the rect_params’s resolution based on?I mean the parameters like width and height must depend on some exact resolution.
When I get the raw images:
Mat nv12_mat = Mat(height*3/2, width, CV_8UC1, surface->surfaceList[frame_meta->batch_id].mappedAddr.addr[0],
surface->surfaceList[frame_meta->batch_id].pitch);
So, is the resolution of nv12_mat same as rect_params?
And if it’s not resolution problem,anything else may result in this?
