detect rectangle in image and crop - python

I have lots of scanned images of handwritten digit inside a rectangle(small one).
Please help me to crop each image containing digits and save them by giving the same name to each row.
import cv2
img = cv2.imread('Data\Scan_20170612_4.jpg')
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
gray = cv2.bilateralFilter(gray, 11, 17, 17)
edged = cv2.Canny(gray, 30, 200)
_, contours, hierarchy = cv2.findContours(edged, cv2.RETR_LIST, cv2.CHAIN_APPROX_SIMPLE)
i = 0
for c in contours:
peri = cv2.arcLength(c, True)
approx = cv2.approxPolyDP(c, 0.09 * peri, True)
if len(approx) == 4:
screenCnt = approx
cv2.drawContours(img, [screenCnt], -1, (0, 255, 0), 3)
cv2.imwrite('cropped\\' + str(i) + '_img.jpg', img)
i += 1

Here is My Version
import cv2
import numpy as np
fileName = ['9','8','7','6','5','4','3','2','1','0']
img = cv2.imread('Data\Scan_20170612_17.jpg')
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
gray = cv2.bilateralFilter(gray, 11, 17, 17)
kernel = np.ones((5,5),np.uint8)
erosion = cv2.erode(gray,kernel,iterations = 2)
kernel = np.ones((4,4),np.uint8)
dilation = cv2.dilate(erosion,kernel,iterations = 2)
edged = cv2.Canny(dilation, 30, 200)
_, contours, hierarchy = cv2.findContours(edged, cv2.RETR_TREE, cv2.CHAIN_APPROX_SIMPLE)
rects = [cv2.boundingRect(cnt) for cnt in contours]
rects = sorted(rects,key=lambda x:x[1],reverse=True)
i = -1
j = 1
y_old = 5000
x_old = 5000
for rect in rects:
x,y,w,h = rect
area = w * h
if area > 47000 and area < 70000:
if (y_old - y) > 200:
i += 1
y_old = y
if abs(x_old - x) > 300:
x_old = x
x,y,w,h = rect
out = img[y+10:y+h-10,x+10:x+w-10]
cv2.imwrite('cropped\\' + fileName[i] + '_' + str(j) + '.jpg', out)
j+=1

That's an easy thing if u try. Here's my output- (The image and its one small bit)
What i did?
Resized the image first because it was too big in my screen
Erode, Dilate to remove small dots and thicken the lines
Threshold the image
Flood fill, beginning at the right point
Invert the flood fill
Find contours and draw one at a time which are in range of approximately the
area on the rectangle. For my resized (500x500) image i put Area of
contour in range 500 to 2500 (trial and error anyway).
Find bounding rectangle and crop that mask from main image.
Then save that piece with proper name- which i didn't do.
Maybe, there's a simpler way, but i liked this. Not putting the code because
i made it all clumsy. Will put if u still need it.
Here's how the mask looks when you find contours each at a time
code:
import cv2;
import numpy as np;
# Run the code with the image name, keep pressing space bar
# Change the kernel, iterations, Contour Area, position accordingly
# These values work for your present image
img = cv2.imread("your_image.jpg", 0);
h, w = img.shape[:2]
kernel = np.ones((15,15),np.uint8)
e = cv2.erode(img,kernel,iterations = 2)
d = cv2.dilate(e,kernel,iterations = 1)
ret, th = cv2.threshold(d, 150, 255, cv2.THRESH_BINARY_INV)
mask = np.zeros((h+2, w+2), np.uint8)
cv2.floodFill(th, mask, (200,200), 255); # position = (200,200)
out = cv2.bitwise_not(th)
out= cv2.dilate(out,kernel,iterations = 3)
cnt, h = cv2.findContours(out,cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE)
for i in range(len(cnt)):
area = cv2.contourArea(cnt[i])
if(area>10000 and area<100000):
mask = np.zeros_like(img)
cv2.drawContours(mask, cnt, i, 255, -1)
x,y,w,h = cv2.boundingRect(cnt[i])
crop= img[ y:h+y,x:w+x]
cv2.imshow("snip",crop )
if(cv2.waitKey(0))==27:break
cv2.destroyAllWindows()

_, contours, hierarchy = cv2.findContours(edged, cv2.RETR_LIST, cv2.CHAIN_APPROX_SIMPLE)
you are using cv2.RETR_LIST to find contours in the image. For your image to get better output use cv2.RETR_EXTERNAL. Before using that first remove black border line from the image.
cv2.RETR_LIST gives you list of all contours for image
cv2.RETR_EXTERNAL gives you only external or outer contours, not internal contours
change line to
_, contours, hierarchy = cv2.findContours(edged, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
Contours Hierarchy

Related

How to remove a contoured area from an image?

I have an image with a white background and some colored blocks. I have created multiple filters to find the colored blocks and get the contours for another purpose and I am able to draw the contours around the colored blocks.
These blocks are connected by some black lines which I would like to get the contours of. I was using the original contours to also get the lines but I was advised not to do that and instead remove the colored blocks from the image so that I would only remain with the black lines in the image making it easier to contour.
I have created a mask that would draw over the contoured block but when I display the final image the contoured blocks are black instead of white.
Is there any way to make the blocks white similar to the background so that I could remain with only the black lines?
From the images, you can see that the mask covers the image and the black line remains. However, I can't figure out how to make the blocks white instead of black so that only the line remains.
from ctypes import sizeof
from doctest import master
from cv2 import approxPolyDP, contourArea, cvtColor, inRange
import numpy as np
import cv2
kernel = (5, 5)
srcImg = cv2.imread('BluePurpleConnected.png', cv2.IMREAD_COLOR)
blur = cv2.GaussianBlur(srcImg, kernel, 0)
hsv = cv2.cvtColor(blur, cv2.COLOR_BGR2HSV)
grayImg = cv2.cvtColor(srcImg, cv2.COLOR_BGR2GRAY)
rows = int(grayImg.shape[0]/2)
cols = int(grayImg.shape[1]/2)
ker = np.ones((0, 0), 'uint8')
graySize = grayImg.shape
sig = 0.33
cPix = 200
bPix = 255
lPurp = np.array([130, 20, 10])
uPurp = np.array([145, 255, 255])
lBlue = np.array([94, 80, 2])
uBlue = np.array([126, 255, 255])
colArray = np.array([lPurp, uPurp, lBlue, uBlue])
masterStruc = []
maskArray = []
mask = np.ones(srcImg.shape[:2], dtype="uint8") * 255
x = 0
while x <= 1:
imgMask = cv2.inRange(hsv, colArray[2*x], colArray[2*x+1])
maskArray.append(imgMask)
v = np.median(imgMask)
lower = int(max(0, (1.0 - sig) * v))
upper = int(min(255, (1.0 + sig) * v))
bwImg = cv2.Canny(imgMask, lower, upper)
nbwImg = cv2.dilate(bwImg, kernel, iterations=1)
cImg = nbwImg
ret, threshold = cv2.threshold(cImg, cPix, bPix, cv2.THRESH_BINARY)
contours, hierarchy = cv2.findContours(threshold, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
cnt = 0
for cnt in contours:
curve = approxPolyDP(cnt, 0.02 * cv2.arcLength(cnt, True), True)
vert = len(curve)
area = cv2.contourArea(curve)
if(area > 1000):
if(vert == 4):
masterStruc.append([x, curve, area])
cv2.drawContours(mask, [curve], -1, 0, -1)
x = x + 1
srcImg = cv2.bitwise_and(srcImg, srcImg, mask=mask)
cv2.imshow('Mask', mask)
cv2.imshow('Image', srcImg)
if cv2.waitKey(0) & 0xFF == ord('q'):
cv2.destroyAllWindows()

Remove shadow from image with OpenCV

I am trying to remove the shadow of the pipe in the following image.
I use the following code to isolate the pipe with the shadow but I cannot find a way to remove the shadow.
img = cv2.imread("myimage.png",cv2.IMREAD_UNCHANGED)
blurred = cv2.GaussianBlur(img, (5, 5), 0)
gray = cv2.cvtColor(blurred, cv2.COLOR_BGR2GRAY)
thresh = cv2.threshold(gray, 120, 255, cv2.THRESH_BINARY_INV)[1]
cnts, _ = cv2.findContours(thresh, cv2.RETR_TREE, cv2.CHAIN_APPROX_SIMPLE)
img_X = img.shape[1] / 2
img_Y = img.shape[0]
img_cnts = None
img_distance = None
for c in cnts:
area = cv2.contourArea(c)
if area < 500:
continue
M = cv2.moments(c)
cnt_X = int(M["m10"] / M["m00"])
cnt_Y = int(M["m01"] / M["m00"])
cnt_distance = math.sqrt(sum((px - qx) ** 2.0 for px, qx in zip([cnt_X, cnt_Y], [img_X, img_Y])))
if img_distance == None or img_distance > cnt_distance:
img_cnts = c
img_distance = cnt_distance
mask = np.zeros_like(img) # Create mask where white is what we want, black otherwise
cv2.drawContours(mask, [img_cnts], -1, (255,255,255), -1) # Draw filled contour in mask
out = np.zeros_like(img) # Extract out the object and place into output image
out[mask == 255] = img[mask == 255]
This is the result of the previous code that is pretty close to what I need.
I tried to use cv2.adaptiveThreshold and cv2.createBackgroundSubtractorMOG without luck.
Well, if you apply adaptive-threshold along with bitwise-not operation result will be:
Of course, different blockSize and C parameters you will get different results.
Where: (source)
blockSize: determines the size of the neighbourhood area
C: constant that is subtracted from the mean or weighted sum of the neighbourhood pixels.
Code:
import cv2
img = cv2.imread("pdUqL.png")
gry = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
thr = cv2.adaptiveThreshold(gry, 255, cv2.ADAPTIVE_THRESH_MEAN_C,
cv2.THRESH_BINARY_INV, blockSize=33, C=31)
bnt = cv2.bitwise_not(thr)
cv2.imshow("out", bnt)
cv2.waitKey(0)
there is no good way to remove the shadow. you need to fix your lighting. use "softboxes" (indirect lighting), multiple lights from multiple angles, and whenever you have mirror surfaces, arrange lights so they don't reflect off that into the camera.

How I can detect recognize text in а shape

Need your help. Now I'm writing python script to recognize text in a shape. This shape can be captured from RTSP (IP Camera) at any angle.
For the example see attached file. My code is here, but coords to crop rotated shape is sets manually
import cv2
import numpy as np
def main():
fn = cv2.VideoCapture("rtsp://admin:Admin123-#172.16.10.254")
flag, img = fn.read()
cnt = np.array([
[[64, 49]],
[[122, 11]],
[[391, 326]],
[[308, 373]]
])
print("shape of cnt: {}".format(cnt.shape))
rect = cv2.minAreaRect(cnt)
print("rect: {}".format(rect))
box = cv2.boxPoints(rect)
box = np.int0(box)
print("bounding box: {}".format(box))
cv2.drawContours(img, [box], 0, (0, 255, 0), 2)
img_crop, img_rot = crop_rect(img, rect)
print("size of original img: {}".format(img.shape))
print("size of rotated img: {}".format(img_rot.shape))
print("size of cropped img: {}".format(img_crop.shape))
new_size = (int(img_rot.shape[1]/2), int(img_rot.shape[0]/2))
img_rot_resized = cv2.resize(img_rot, new_size)
new_size = (int(img.shape[1]/2)), int(img.shape[0]/2)
img_resized = cv2.resize(img, new_size)
cv2.imshow("original contour", img_resized)
cv2.imshow("rotated image", img_rot_resized)
cv2.imshow("cropped_box", img_crop)
# cv2.imwrite("crop_img1.jpg", img_crop)
cv2.waitKey(0)
def crop_rect(img, rect):
# get the parameter of the small rectangle
center = rect[0]
size = rect[1]
angle = rect[2]
center, size = tuple(map(int, center)), tuple(map(int, size))
# get row and col num in img
height, width = img.shape[0], img.shape[1]
print("width: {}, height: {}".format(width, height))
M = cv2.getRotationMatrix2D(center, angle, 1)
img_rot = cv2.warpAffine(img, M, (width, height))
img_crop = cv2.getRectSubPix(img_rot, size, center)
return img_crop, img_rot
if __name__ == "__main__":
main()
example pic
You may start with the example in the following post.
The code sample detects the license plate, and it also detects your "shape" with text.
After detecting the "shape" with the text, you may use the following stages:
Apply threshold the cropped area.
Find contours, and find the contour with maximum area.
Build a mask, and mask area outside the contour (like in the license plate example).
Use minAreaRect (as fmw42 commented), and get the angle of the rectangle.
Rotate the cropped area (by angle+90 degrees).
Apply OCR using pytesseract.image_to_string.
Here is the complete code:
import cv2
import numpy as np
import imutils
import pytesseract
pytesseract.pytesseract.tesseract_cmd = r'C:\Program Files\Tesseract-OCR\tesseract.exe' # I am using Windows
# Read the input image
img = cv2.imread('Admin123.jpg')
# Reused code:
# https://stackoverflow.com/questions/60977964/pytesseract-not-recognizing-text-as-expected/60979089#60979089
################################################################################
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY) #convert to grey scale
gray = cv2.bilateralFilter(gray, 11, 17, 17)
edged = cv2.Canny(gray, 30, 200) #Perform Edge detection
cnts = cv2.findContours(edged.copy(), cv2.RETR_TREE, cv2.CHAIN_APPROX_SIMPLE)
cnts = imutils.grab_contours(cnts)
cnts = sorted(cnts, key = cv2.contourArea, reverse = True)[:10]
screenCnt = None
# loop over our contours
for c in cnts:
# approximate the contour
peri = cv2.arcLength(c, True)
approx = cv2.approxPolyDP(c, 0.018 * peri, True)
# if our approximated contour has four points, then
# we can assume that we have found our screen
if len(approx) == 4:
screenCnt = approx
break
# Masking the part other than the "shape"
mask = np.zeros(gray.shape,np.uint8)
new_image = cv2.drawContours(mask,[screenCnt],0,255,-1,)
new_image = cv2.bitwise_and(img,img,mask=mask)
# Now crop
(x, y) = np.where(mask == 255)
(topx, topy) = (np.min(x), np.min(y))
(bottomx, bottomy) = (np.max(x), np.max(y))
cropped = gray[topx:bottomx+1, topy:bottomy+1]
################################################################################
# Apply threshold the cropped area
_, thresh = cv2.threshold(cropped, 0, 255, cv2.THRESH_BINARY_INV + cv2.THRESH_OTSU)
# Find contours
cnts = cv2.findContours(thresh, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_NONE)
cnts = imutils.grab_contours(cnts)
# Get contour with maximum area
c = max(cnts, key=cv2.contourArea)
# Build a mask (same as the code above)
mask = np.zeros(cropped.shape, np.uint8)
new_cropped = cv2.drawContours(mask, [c], 0, 255, -1)
new_cropped = cv2.bitwise_and(cropped, cropped, mask=mask)
# Draw green rectangle for testing
test = cv2.cvtColor(new_cropped, cv2.COLOR_GRAY2BGR)
cv2.drawContours(test, [c], -1, (0, 255, 0), thickness=2)
# Use minAreaRect as fmw42 commented
rect = cv2.minAreaRect(c)
angle = rect[2] # Get angle of the rectangle
# Rotate the cropped rectangle.
rotated_cropped = imutils.rotate(new_cropped, angle + 90)
# Read the text in the "shape"
text = pytesseract.image_to_string(rotated_cropped, config='--psm 3')
print("Extracted text is:\n\n", text)
# Show images for testing:
cv2.imshow('cropped', cropped)
cv2.imshow('thresh', thresh)
cv2.imshow('test', test)
cv2.imshow('rotated_cropped', rotated_cropped)
cv2.waitKey(0)
cv2.destroyAllWindows()
OCR output result:
AB12345
DEPARTMENT OF
INFORMATION
COMMUNICATION
TECHNOLOGY
cropped:
thresh:
test:
rotated_cropped:

How to separate images using watershed algorithm in Python

How to separate indiviual images among multiple images after image segmentaion using watershed algorithm in Python
The attached image is consists of 4 images , from which we need to apply image segmentation and separate individual image from those 4 images
We will flood fill it first
import cv2;
import numpy as np;
# Read image
im_in = cv2.imread("2SNAT.jpg", cv2.IMREAD_GRAYSCALE);
# Threshold.
# Set values equal to or above 220 to 0.
# Set values below 220 to 255.
th, im_th = cv2.threshold(im_in, 220, 255, cv2.THRESH_BINARY_INV);
# Copy the thresholded image.
im_floodfill = im_th.copy()
# Mask used to flood filling.
# Notice the size needs to be 2 pixels than the image.
h, w = im_th.shape[:2]
mask = np.zeros((h+2, w+2), np.uint8)
# Floodfill from point (0, 0)
cv2.floodFill(im_floodfill, mask, (0,0), 255);
# Invert floodfilled image
im_floodfill_inv = cv2.bitwise_not(im_floodfill)
# Combine the two images to get the foreground.
im_out = im_th | im_floodfill_inv
Then find contour and crop out
im, contours, hierarchy = cv2.findContours(im_out.copy(), cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_NONE)
final_contours = []
for contour in contours:
area = cv2.contourArea(contour)
if area > 1000:
final_contours.append(contour)
Crop out step, also drawing rectangle on original image
counter = 0
for c in final_contours:
counter = counter + 1
# for c in [final_contours[0]]:
peri = cv2.arcLength(c, True)
approx = cv2.approxPolyDP(c, 0.01 * peri, True)
x,y,w,h = cv2.boundingRect(approx)
print(x, y, w, h)
aspect_ratio = w / float(h)
if (aspect_ratio >= 0.8 and aspect_ratio <= 4):
cv2.rectangle(im_in,(x,y),(x+w,y+h),(0,255,0),2)
cv2.imwrite('splitted_{}.jpg'.format(counter), im_in[y:y+h, x:x+w])
cv2.imwrite('rectangled_split.jpg', im_in)
Instead of using watershed, here's a simple approach using thresholding + morphological operations. The idea is to obtain a binary image then perform morph close to combine each object as a single contour. We then find contours and extract/save each ROI using Numpy slicing.
Here's each individual object highlighted in green
Individual saved object
Code
import cv2
# Load image, grayscale, Otsu's threshold
image = cv2.imread('1.jpg')
original = image.copy()
gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
thresh = cv2.threshold(gray, 0, 255, cv2.THRESH_BINARY_INV + cv2.THRESH_OTSU)[1]
# Morph close
kernel = cv2.getStructuringElement(cv2.MORPH_RECT, (7,7))
close = cv2.morphologyEx(thresh, cv2.MORPH_CLOSE, kernel, iterations=3)
# Find contours and extract ROI
cnts = cv2.findContours(close, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
cnts = cnts[0] if len(cnts) == 2 else cnts[1]
num = 0
for c in cnts:
x,y,w,h = cv2.boundingRect(c)
cv2.rectangle(image, (x, y), (x + w, y + h), (36,255,12), 2)
ROI = original[y:y+h, x:x+w]
cv2.imwrite('ROI_{}.png'.format(num), ROI)
num += 1
cv2.imshow('image', image)
cv2.waitKey()

Detect regtangles in a low contrast image using opencv in python for reading by tesseract

I would like to detect the labels in images like this one for the purpose of extracting the text using tesseract. I have tried various combinations of thresholding and using edge detection. However I can only detect about half of the labels at a time at max. These are a few of the images I've been trying to read the labels from:
enter image description here
enter image description here
All of the labels have the same aspect ratio (the width is 3.5 times larger than the height) so I'm trying to find contours that have a minAreaRect with that same aspect ratio. The hard part is handing the labels on the lighter background. This is the code I have so far:
from PIL import Image
import pytesseract
import numpy as np
import argparse
import cv2
import os
ap = argparse.ArgumentParser()
ap.add_argument("-i", "--image", required=True,
help="path to input image to be OCR'd")
args = vars(ap.parse_args())
#function to crop an image to a minAreaRect
def crop_minAreaRect(img, rect):
# rotate img
angle = rect[2]
rows,cols = img.shape[0], img.shape[1]
M = cv2.getRotationMatrix2D((cols/2,rows/2),angle,1)
img_rot = cv2.warpAffine(img,M,(cols,rows))
# rotate bounding box
rect0 = (rect[0], rect[1], 0.0)
box = cv2.boxPoints(rect)
pts = np.int0(cv2.transform(np.array([box]), M))[0]
pts[pts < 0] = 0
# crop
img_crop = img_rot[pts[1][1]:pts[0][1],
pts[1][0]:pts[2][0]]
return img_crop
# load image and apply threshold
image = cv2.imread(args["image"])
bw = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
#bw = cv2.threshold(bw, 210, 255, cv2.THRESH_BINARY)[1]
bw = cv2.adaptiveThreshold(bw, 255, cv2.ADAPTIVE_THRESH_GAUSSIAN_C, cv2.THRESH_BINARY, 27, 20)
#do edge detection
v = np.median(bw)
sigma = 0.5
lower = int(max(0, (1.0 - sigma) * v))
upper = int(min(255, (1.0 + sigma) * v))
bw = cv2.Canny(bw, lower, upper)
kernel = np.ones((5,5), np.uint8)
bw = cv2.dilate(bw,kernel,iterations=1)
#find contours
image2, contours, hierarchy = cv2.findContours(bw,cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE)
bw = cv2.drawContours(bw,contours,0,(0,0,255),2)
cv2.imwrite("edge.png", bw)
#test which contours have the correct aspect ratio
largestarea = 0.0
passes = []
for contour in contours:
(x,y),(w,h),a = cv2.minAreaRect(contour)
if h > 20 and w > 20:
if h > w:
maxdim = h
mindim = w
else:
maxdim = w
mindim = h
ratio = maxdim/mindim
print("ratio: {}".format(ratio))
if (ratio > 3.4 and ratio < 3.6):
passes.append(contour)
if not passes:
print "no passes"
exit()
passboxes = []
i = 1
#crop out each label and attemp to extract text
for ps in passes:
rect = cv2.minAreaRect(ps)
bw = crop_minAreaRect(image, rect)
cv2.imwrite("{}.png".format(i), bw)
i += 1
h, w = bw.shape[:2]
print str(h) + "x" + str(w)
if w and h:
bw = cv2.cvtColor(bw, cv2.COLOR_BGR2GRAY)
bw = cv2.threshold(bw, 50, 255, cv2.THRESH_BINARY | cv2.THRESH_OTSU)[1]
cv2.imwrite("output.png", bw)
im = Image.open("output.png")
w, h = im.size
print "W:{} H:{}".format(w,h)
if h > w:
print ("rotating")
im.rotate(90)
im.save("output.png")
print pytesseract.image_to_string(Image.open("output.png"))
im.rotate(180)
im.save("output.png")
print pytesseract.image_to_string(Image.open("output.png"))
box = cv2.boxPoints(cv2.minAreaRect(ps))
passboxes.append(np.int0(box))
im.close()
cnts = cv2.drawContours(image,passboxes,0,(0,0,255),2)
cnts = cv2.drawContours(cnts,contours,-1,(255,255,0),2)
cnts = cv2.drawContours(cnts, passes, -1, (0,255,0), 3)
cv2.imwrite("output2.png", image)
I believe the problem I have could be the parameters for the thresholding. Or I could be over complicating this.
Only the white labels with "A-08337" and such? The following detects all of them on both images:
import numpy as np
import cv2
img = cv2.imread('labels.jpg')
#downscale the image because Canny tends to work better on smaller images
w, h, c = img.shape
resize_coeff = 0.25
img = cv2.resize(img, (int(resize_coeff*h), int(resize_coeff*w)))
#find edges, then contours
canny = cv2.Canny(img, 100, 200)
_, contours, _ = cv2.findContours(canny, cv2.RETR_TREE, cv2.CHAIN_APPROX_SIMPLE)
#draw the contours, do morphological close operation
#to close possible small gaps, then find contours again on the result
w, h, c = img.shape
blank = np.zeros((w, h)).astype(np.uint8)
cv2.drawContours(blank, contours, -1, 1, 1)
blank = cv2.morphologyEx(blank, cv2.MORPH_CLOSE, np.ones((3, 3), np.uint8))
_, contours, _ = cv2.findContours(blank, cv2.RETR_TREE, cv2.CHAIN_APPROX_SIMPLE)
#keep only contours of more or less correct area and perimeter
contours = [c for c in contours if 800 < cv2.contourArea(c) < 1600]
contours = [c for c in contours if cv2.arcLength(c, True) < 200]
cv2.drawContours(img, contours, -1, (0, 0, 255), 1)
cv2.imwrite("contours.png", img)
Probably with some additional convexity check you can get rid of the "Verbatim" contours and such (for example, only keep contours with near zero difference between their area and their convex hull's area).

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