opencv dnn模块研究

DNN：Deep Neural Network 深度神经网络

• MatShape

• Backend（）

• Target（）

        CPU/GPU

• blobFromImage(image,size,mean,scalefactor,swapRB,crop) 

image	input image (with 1-, 3- or 4-channels).
size	spatial size for output image
mean	scalar with mean values which are subtracted from channels. Values are intended to be in (mean-R, mean-G, mean-B) order if image has BGR ordering and swapRB is true.
scalefactor	multiplier for image values.
swapRB	flag which indicates that swap first and last channels in 3-channel image is necessary.
crop	flag which indicates whether image will be cropped after resize or not

• NMSBoxes(bboxes,scores,score_threshold,nms_threshold,indices,eta,top_k)

bboxes	a set of bounding boxes to apply NMS.
scores	a set of corresponding confidences.
score_threshold	a threshold used to filter boxes by score.
nms_threshold	a threshold used in non maximum suppression.
indices	the kept indices of bboxes after NMS.
eta	a coefficient in adaptive threshold formula: nms_thresholdi+1=eta⋅nms_thresholdi.
top_k	if >0, keep at most top_k picked indices.

• readNet()

model	Binary file contains trained weights. The following file extensions are expected for models from different frameworks: *.caffemodel (Caffe, http://caffe.berkeleyvision.org/) *.pb (TensorFlow, https://www.tensorflow.org/) *.t7 | *.net (Torch, http://torch.ch/) *.weights (Darknet, https://pjreddie.com/darknet/) *.bin (DLDT, https://software.intel.com/openvino-toolkit)
config	Text file contains network configuration. It could be a file with the following extensions: *.prototxt (Caffe, http://caffe.berkeleyvision.org/) *.pbtxt (TensorFlow, https://www.tensorflow.org/) *.cfg (Darknet, https://pjreddie.com/darknet/) *.xml (DLDT, https://software.intel.com/openvino-toolkit)