81
questions
0
votes
0
answers
42
views
Difficulty in finding the right parameter for cX and cY in my OMR project
OMR detection in stackedimages
this is the output of my python code
this is the main code
import cv2
import numpy as np
import utiliss
#######################
path = "omr_sheetF2.jpg"
...
0
votes
0
answers
50
views
Struggling with using an OMR to detect checkboxes
Good morning! Right now, I'm working on a project that takes a paper form and converts it into an Excel spreadsheet. The unfortunate problem I'm working to solve is actually detecting the checkboxes ...
1
vote
1
answer
194
views
Using python OpenCV to crop an image based on reference marks
I have an image I would like to crop based on reference marks of the image which are black squares at the layout margins.
While my code can detect the reference marks, there seem to be a persistent ...
- 1,013
0
votes
2
answers
531
views
Detect if a checkbox is checked OpenCV
I am using OpenCV to process an image of a form which contains main checkboxes. I have used the pixel coordinates to crop around the checkbox so all I am left with is just the single checkbox. From ...
- 811
0
votes
1
answer
162
views
How to detect rectangles and rotate them in the correct direction in image
I have block code like this.
def crop_image(self,img):
cnts,gray_img = self.pre_processing_img(img)
ans_blocks = []
x_old, y_old, w_old, h_old = 0, 0, 0, 0
if len(cnts)...
- 55
0
votes
1
answer
450
views
How can I read answer sheet with python opencv?
I have an answer sheet. I want to identify the fields marked on it and check whether they are correct or incorrect.
I have come to a certain stage.
I get the results in the picture below.
But even ...
- 1
0
votes
0
answers
65
views
plot bboxes detected in transformed image in original image
I am writing a code to automatically correct bubble sheets 4 choices.
I want to plot bboxes around blacked rectangles(selected by students for the question)
now I am using cv2.findContours and imutils....
1
vote
0
answers
61
views
Detecting rectangular corners with python cv2
I'm trying to implement an optical mark-recognition with python opencv. As part of the program, I used a pre-"filter" to transform the original image into a binary one and then use contour ...
- 9
-1
votes
2
answers
148
views
CV2 - rectangular detecting issue
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 ...
- 9
1
vote
0
answers
97
views
How to extract pencil markings from the below sheet using opencv in python
I am unable to extract the pencil markings provided in the below picture using opencv. I am unsure if it's because of the kernel size (though I tried playing with the size), but the extraction is not ...
1
vote
1
answer
124
views
Hough Gradient Method misses some circles
Consider the images below:
As can be seen, many circles are not detected. I have already played with
param1 and param2 (cv2.HoughCircles)
in the code below:
import cv2
import numpy as np
from PIL ...
- 24.8k
0
votes
0
answers
237
views
OpenCV: How to extract the inner area of a series of rectangles that are arranged in a particular way?
I have a series of images which are like the image A. My intention is to detect the inner area of each rectangle and extract that area for further processing; so what I need are the position (x,y) and ...
- 2,025
-1
votes
1
answer
430
views
How to get the marked answer from a OMR Sheet?
I am trying to figure out the marked answer from a OMR Sheet. I have been able to spot the dark circle on the image(Please see the green square around it) but I am stuck now. How to find the exact ...
- 129
0
votes
0
answers
72
views
Line 21, in <module> image_id = annotation['image_id'] TypeError: string indices must be integers, not 'str'
import json
import numpy as np
from PIL import Image
from keras.models import Sequential
from keras.layers import Dense, Dropout, Flatten, Conv2D, MaxPooling2D
with open('deepscores_train.json', 'r') ...
- 1
0
votes
0
answers
89
views
Handwritten cross inside a square image recognition
this is a long one. I am currently (from way too much time) trying to differentiate between crossed out square, completely blacked out square, blank square, crossed out/blacked out circle and blank ...
- 289