object-detection
OpenCV C++/Obj-C: Advanced square detection
You might try using HoughLines to detect the four sides of the square. Next, locate the four resulting line intersections to detect the corners. The Hough transform is fairly robust to noise and occlusions, so it could be useful here. Also, here is an interactive demo showing how the Hough transform works (I thought it … Read more
Parameters of detectMultiScale in OpenCV using Python
Amongst these parameters, you need to pay more attention to four of them: scaleFactor – Parameter specifying how much the image size is reduced at each image scale. Basically, the scale factor is used to create your scale pyramid. More explanation, your model has a fixed size defined during training, which is visible in the … Read more
OpenCV Object Detection – Center Point
There’s already an example of how to do rectangle detection in OpenCV (look in samples/squares.c), and it’s quite simple, actually. Here’s the rough algorithm they use: 0. rectangles <- {} 1. image <- load image 2. for every channel: 2.1 image_canny <- apply canny edge detector to this channel 2.2 for threshold in bunch_of_increasing_thresholds: 2.2.1 … Read more
OpenCV: draw a rectangle around a region
please don’t try with the old cv module, use cv2: import cv2 cv2.rectangle(img, (x1, y1), (x2, y2), (255,0,0), 2) x1,y1 —— | | | | | | ——–x2,y2 [edit] to append the follow-up questions below: cv2.imwrite(“my.png”,img) cv2.imshow(“lalala”, img) k = cv2.waitKey(0) # 0==wait forever
Tensorflow serving No versions of servable found under base path
I had same problem, the reason is because object detection api does not assign version of your model when exporting your detection model. However, tensorflow serving requires you to assign a version number of your detection model, so that you could choose different versions of your models to serve. In your case, you should put … Read more
OpenCV detectMultiScale() minNeighbors parameter
Haar cascade classifier works with a sliding window approach. If you look at the cascade files you can see a size parameter which usually a pretty small value like 20 20. This is the smallest window that cascade can detect. So by applying a sliding window approach, you slide a window through out the picture … Read more
AttributeError: module ‘tensorflow’ has no attribute ‘app’
try using import tensorflow.compat.v1 as tf
What are good algorithms for vehicle license plate detection? [closed]
There are a number of approaches you can take but the first strategy that pops into mind is to: Discovery/research: Identify the set of colors and fonts that you may need to identify. If your sample picture is representative of most British plates then your job is made easier. E.g. Simple, singular font and black … Read more
Calculating percentage of Bounding box overlap, for image detector evaluation
For axis-aligned bounding boxes it is relatively simple. “Axis-aligned” means that the bounding box isn’t rotated; or in other words that the boxes lines are parallel to the axes. Here’s how to calculate the IoU of two axis-aligned bounding boxes. def get_iou(bb1, bb2): “”” Calculate the Intersection over Union (IoU) of two bounding boxes. Parameters … Read more