CV2 - rectangular detecting issue

CV2 - rectangular detecting issue

2024/11/15 23:48:52

I'm trying to implement an OMR using python's CV2. As part of the code I need to find the corners of the choices box (rectangulars) however I ran into difficulty causes by the grade sheet template.

In the grade sheet template that I'm working on (image 1) there are two verticals black lines that goes through all the rectangular that I'm trying to detect. when I used cv2.findContours after applying all the blur and canny stuff, it recognized all the rectangular as two contours instead of 8 rectangular like I expected (image 2). If someone has an idea of how to get around it I will really appreciate it.

image 1 image 2

Answer

The merged contours are wonderfully detected. Now it suffices to traverse them and find the right angles. From this you can easily isolate the individual rectangles.

https://en.xdnf.cn/q/119598.html

Related Q&A

Keras/TensorFlow - high acc, bad prediction

Im new to machine learning and Im trying to train a model which detects Prague city in a sentence. It can be in many word forms.Prague, PRAHA, Z Prahy etc...So I have a train dataset which consists of …

Flask-HTTPAuth: how to pass an extra argument to a function decorated with @auth.verify_password?

Heres a small Flask app authenticated with Flask-HTTPAuth. How to pass an argument (such as authentication on/off flag, or verbosity level / debug on/off flag) to a function (such as authenticate below…

AttributeError: numpy.ndarray object has no attribute split

Given a text file with one DNA sequence on each line and joining these together I now want to split the string into 5 sequences (corresponding to each of the 5 rows). This is the file source: http://ww…

How do I determine if a lat/long point is within a polygon?

I have a shapefile of all the counties that make up my state. Using the shapefile (which contains geometric for the district polygons) I was able to use geopandas to plot the shapes in a figure. I have…

How to return different types of arrays?

The high level problem Im having in C# is to make a single copy of a data structure that describes a robot control network packet (Ethercat), and then to use that single data structure to extract data …

How do I pass an array of strings to a python script as an argument?

Ive written a swift app that outputs an array of strings. I would like to import this array into a python script for further processing into an excel file via xlsxwriter, I would like to do this as an …

Match values of different dataframes

This dataframe is the principal with the original tweets. "original_ds_.csv" id tweet --------------------------------------------- 78 "onetoone"…

EOF while parsing

def main():NUMBER_OF_DAYS = 10NUMBER_OF_HOURS = 24data = []for i in range(NUMBER_OF_DAYS):data.append([])for j in range(NUMBER_OF_HOURS):data[i].append([])data[i][j].append(0)data[i][j].append(0)for k …

Why is bool(x) where x is any integer equal to True

I expected bool(1) to equate to True using Python - it does - then I expected other integers to error when converted to bool but that doesnt seem to be the case:>>> x=23 #<-- replace with a…

Getting TypeError while fetching value from table using Python and Django

I am getting error while fetching value from table using Python and Django. The error is below:Exception Type: TypeError Exception Value: not all arguments converted during string formattingMy code…

Latest Q&A