cv2.resize() unable to use with (y, x) matrix - python-3.x

I'm trying to calibrate HD Camera, resolution 1280x720.
I need it to be resized after applying undistort function to size 640x480.
So it's changing aspect ratio from 16:9 to 4:3.
In my opencv application anything works flawless besides saving (y, x) positions of calibrated camera. I need it because, binary output file is working with flashplayer application that reads this changed camera (y, x) positions and applyies it to original camera view that is being grabbed by flashplayer.
Binary file with cv2.resize():
def generate_grid(rows, cols):
"""Generate grid filed with y,x values at desired size"""
cc, rr = np.meshgrid(np.arange(cols, dtype=np.uint16), np.arange(rows, dtype=np.uint16))
return np.dstack([rr, cc])
camera_size = (1280, 720)
binary_size = (320, 240)
raw_grid = generate_grid(camera_size[1], camera_size[0])
undist_grid = cv2.undistort(raw_grid, camera_matrix, dist_coeffs)
resized_grid = cv2.resize(undist_grid, (320, 240))
transformed_grid = cv2.warpPerspective(resized_grid, transformed_matrix, binary_size)
with open(path_to_binary_file, "wb") as binary_file:
num_bytes_written = binary_file.write(transformed_grid)
print(transformed_grid.shape)
print("Wrote %d bytes." % num_bytes_written)
Output image read by flashplayer apllication:
Binary file with naive algorithm:
def generate_grid(rows, cols):
"""Generate grid filed with y,x values at desired size"""
cc, rr = np.meshgrid(np.arange(cols, dtype=np.uint16), np.arange(rows, dtype=np.uint16))
return np.dstack([rr, cc])
camera_size = (1280, 720)
binary_size = (320, 240)
raw_grid = generate_grid(camera_size[1], camera_size[0])
undist_grid = cv2.undistort(raw_grid, camera_matrix, dist_coeffs)
resized_grid = generate_grid(480, 640)
_resized_grid = generate_grid(binary_size[1], binary_size[0])
for y in range(undist_grid.shape[0]):
for x in range(undist_grid.shape[1]):
if y % 2 != 0 and x % 2 != 0:
yy = int(y / 2)
xx = int(x / 2)
resized_grid[yy, xx, :] = undist_grid[y, x] / 2
for y in range(resized_grid.shape[0]):
for x in range(resized_grid.shape[1]):
if y % 2 != 0 and x % 2 != 0:
yy = int(y / 2)
xx = int(x / 2)
_resized_grid[yy, xx, :] = resized_grid[y, x] / 2
transformed_grid = cv2.warpPerspective(_resized_grid, transformed_matrix, binary_size)
with open(path_to_binary_file, "wb") as binary_file:
num_bytes_written = binary_file.write(transformed_grid)
print(transformed_grid.shape)
print("Wrote %d bytes." % num_bytes_written)
Output image read by flashplayer application:
So in the naive case, I can see that this transformation from 1280x720 to 640x480 is wrong because normally it would be 640x360.
My questions are:
Am I using the cv2.resize() function in the wrong way?
Is there a better way to generate (y, x) points from undistorted camera view?
How can I implement resize 1280x720 to 640x480 in naive algorithm?
#Edit
My application is working okay.
I'm stuck on transferring, changed camera data to binary file.

I could not get to work numpy 2d array with cv2.resize()
but finally I could get (y, x) 720,1280 array to be "scaled" to 480x640
for y in range(undist_grid.shape[0]):
for x in range(undist_grid.shape[1]):
if y % 3 != 0 and x % 2 != 0:
yy = int((2*y) / 3)
xx = int(x / 2)
resized_grid[yy, xx, :] = (2 * undist_grid[y, x]) / 3

Related

Only integer scalar arrays can be converted to a scalar index not running under Spyder

I have the following code, which runs well under Visual Studio Code with python 3.9.10, opencv 4.5.5 and numpy 1.22.1.
I would like to migrate this code into the Spyder IDE (Version 5, another notebook), python 3.8, opencv 4.5.1 and numpy 1.22.2.
In spyder, I get the error message TypeError: only integer scalar arrays can be converted a scalar index in line: output_layers = [layer_names[i-1]...] (marked line down in the code section)
I have already checked other answers on this site such as
TypeError when indexing a list with a NumPy array: only integer scalar arrays can be converted to a scalar index
which suggests list comprehension, but in my understanding I am already implemented this.
What is the reason for running currectly in on environment but not in the other?
import cv2
import numpy as np
def get_output_layers(net):
layer_names = net.getLayerNames()
output_layers = [layer_names[i - 1] for i in net.getUnconnectedOutLayers()]
return output_layers
def draw_prediction(img, class_id, confidence, x, y, x_plus_w, y_plus_h):
label = str(classes[class_id])
color = COLORS[class_id]
cv2.rectangle(img, (x,y), (x_plus_w,y_plus_h), color, 2)
cv2.putText(img, label, (x-10,y-10), cv2.FONT_HERSHEY_SIMPLEX, 0.5, color, 2)
image = cv2.imread('horses.jpg')
Width = image.shape[1]
Height = image.shape[0]
scale = 0.00392
classes = None
with open(r'yolov3.txt', 'r') as f:
classes = [line.strip() for line in f.readlines()]
COLORS = np.random.uniform(0, 255, size=(len(classes), 3))
net = cv2.dnn.readNet('yolov3.weights','yolov3.cfg')
blob = cv2.dnn.blobFromImage(image, scale, (416,416), (0,0,0), True, crop=False)
net.setInput(blob)
outs = net.forward(get_output_layers(net))
class_ids = []
confidences = []
boxes = []
conf_threshold = 0.5
nms_threshold = 0.4
for out in outs:
for detection in out:
scores = detection[5:]
class_id = np.argmax(scores)
confidence = scores[class_id]
if confidence > 0.5:
center_x = int(detection[0] * Width)
center_y = int(detection[1] * Height)
w = int(detection[2] * Width)
h = int(detection[3] * Height)
x = center_x - w / 2
y = center_y - h / 2
class_ids.append(class_id)
confidences.append(float(confidence))
boxes.append([x, y, w, h])
indices = cv2.dnn.NMSBoxes(boxes, confidences, conf_threshold, nms_threshold)
for i in indices:
box = boxes[i]
x = box[0]
y = box[1]
w = box[2]
h = box[3]
draw_prediction(image, class_ids[i], confidences[i], round(x), round(y),
round(x+w), round(y+h))
cv2.imshow("object detection", image)
cv2.waitKey()
cv2.imwrite("object-detection.jpg", image)
cv2.destroyAllWindows()
there were subtle, recent api changes wrt handling std::vector in python
(4.5.1 still expects a 2d array, but it's 1d in 4.5.5)
to avoid the whole trouble, please simply use:
output_layers = net.getUnconnectedOutLayersNames()
(like it is done in the sample)

how to calculate the skew slopes of the skewed document using connnected components opencv python?

I am using Connected components(NN) method to detect and correct the skew document.I have an image of skew document.I have done the following steps :
1.document image preprocessing.
2.elegible connected components
def imshow(image1):
plt.figure(figsize=(20,10)
plt.imshow(image1)
output = cv2.connectedComponentsWithStats(invr_binary, connectivity, cv2.CV_32S)
(numLabels, labels, stats, centroids) = output
## non text removal
w_avg=stats[1:, cv2.CC_STAT_WIDTH].mean()
h_avg=stats[1: , cv2.CC_STAT_HEIGHT].mean()
B_max=(w_avg * h_avg) * 4
B_min=(w_avg * h_avg) * 0.25
result = np.zeros((labels.shape), np.uint8)
output1=image.copy()
a, b=0.6, 2
for i in range(0, numLabels - 1):
area=stats[i, cv2.CC_STAT_AREA]
if area>B_min and area<B_max: ## non text removal
result[labels == i + 1] = 255
x = stats[i, cv2.CC_STAT_LEFT]
y = stats[i, cv2.CC_STAT_TOP]
w = stats[i, cv2.CC_STAT_WIDTH]
h = stats[i, cv2.CC_STAT_HEIGHT]
area = stats[i, cv2.CC_STAT_AREA]
(cX, cY) = centroids[i]
c=w/h
if a<c and c<b: ## A and C type filtering
result[labels == i + 1] = 255
cv2.rectangle(output1, (x, y), (x + w, y + h), (0, 255, 0), 1)
cv2.circle(output1, (int(cX), int(cY)), 1, (0, 0, 255), -1)
imshow(output1)
input image :
output image :
After finding the center points of the text which is shown in the output image.Now is the next step skew slop calculation. But I could not understand that how to calculate that.I am using that research papers link :3.3(page no. 7)
https://www.mdpi.com/2079-9292/9/1/55/pdf

Delay in output video stream when using YOLOV3 Detection using OpenCV

This is my Code of Mask Detection using YOLOV3 weights created by me. Whenever I run my Program, I experience a delay in my output Video of detection. This is the code please have a look.
import cv2
import numpy as np
net = cv2.dnn.readNet("yolov3_custom_final.weights", "yolov3_custom.cfg")
with open("obj.name", "r") as f:
classes = f.read().splitlines()
cap = cv2.VideoCapture(0 + cv2.CAP_DSHOW)
while True:
ret, img = cap.read()
height, weight, _ = img.shape
blob = cv2.dnn.blobFromImage(img, 1 / 255, (416, 416), (0, 0, 0), swapRB=True, crop=False)
net.setInput(blob)
output = net.getUnconnectedOutLayersNames()
layers = net.forward(output)
box = []
confidences = []
class_ids = []
for out in layers:
for detection in out:
scores = detection[5:]
class_id = np.argmax(scores)
confidence = scores[class_id]
if confidence > 0.3:
centre_x = int(detection[0] * weight)
centre_y = int(detection[1] * height)
w = int(detection[2] * weight)
h = int(detection[3] * height)
x = int(centre_x - w / 2)
y = int(centre_y - h / 2)
box.append([x, y, w, h])
confidences.append(float(confidence))
class_ids.append(class_id)
indexes = np.array(cv2.dnn.NMSBoxes(box, confidences, 0.5, 0.4))
font = cv2.FONT_HERSHEY_PLAIN
colors = np.random.uniform(0, 255, size=(len(box), 3))
for i in indexes.flatten():
x, y, w, h = box[i]
label = str(classes[class_ids[i]])
confidence = str(round(confidences[i], 2))
color = colors[i]
cv2.rectangle(img, (x, y), (x + w, y + h), color, 2)
cv2.putText(img, label + "I" + confidence, (x, y + 20), font, 2, (255, 255, 255), 2)
cv2.imshow("Final", img)
if cv2.waitKey(1) & 0xff == ord("q"):
break
cap.release()
cv2.destroyAllWindows()
Can someone Please help me in this Issue or suggest a way to reduce the Lag in my Output videostream ?
As I have done some research over the Time, I have a found a Possible answer to this question. As I'm running my YOLO model in my local system which has no GPU, This is the factor that is causing a delay in the Output as it Processes a frame and takes another frame after completion.

What is the best way to extract text contained within a table in a pdf using python?

I'm constructing a program to extract text from a pdf, put it in a structured format, and send it off to a database. I have roughly 1,400 individual pdfs that all follow a similar format, but nuances in the verbiage and plan designs that the documents summarize make it tricky.
I've played around with a couple different pdf readers in python including tabula-py and pdfminer but none of them are quite getting to what I'd like to do. Tabula reads in all of the text very well, however it pulls everything as it explicitly lays horizontally, excluding the fact that some of the text is wrapped in a box. For example, if you open up the sample SBC I have attached where it reads "What is the overall deductible?" Tabula will read in "What is the overall $500/Individual or..." skipping the fact that the word "deductible" is really part of the first sentence. (Note the files I'm working with are pdfs but I've attached a jpeg because I couldn't figure out how to attach a pdf.)
import tabula
df = tabula.read_pdf(*filepath*, pandas_options={'header': None))
print(df.iloc[0][0])
print(df)
In the end, I'd really like to be able to parse out the text within each box so that I can better identify what values belong to deductible, out-of-pocket limts, copays/coinsurance, etc. I thought possibly some sort of OCR would allow me to recognize which parts of the PDF are contained in the blue rectangles and then pull the string from there, but I really don't know where to start with that.Sample SBC
#jpnadas In this case the code you copied from my answer in this post isn't really suitable because it addresses the case when a table doesn't have surrounding grid. That algorithm looks for repeating blocks of texts and tries to find a pattern that resembles a table heuristically.
But in this particular case the table does have the grid and by taking this advantage we can achieve a lot more accurate result.
The strategy is the following:
Increase image gamma to make the grid darker
Get rid of colour and apply Otsu thresholding
Find long vertical an horizontal lines in the image and create a mask from it using erode and dilate functions
Find the cell blocks in the mask using findContours function.
Find table objects
5.1 The rest can be as in the post about finding a table without the
grid: find table structure heuristically
5.2 Alternative approach could be using hierarchy returned by the findContours function. This approach is even more accurate and
allows to find multiple tables on a single image.
Having cell coordinates it's easy to extract certain cell image from the original image:
cell_image = image[cell_y:cell_y + cell_h, cell_x:cell_x + cell_w]
Apply OCR to each cell_image.
BUT! I consider the OpenCV approach as a last resort when you're not able to read the PDF's contents: for instance in case when a PDF contains raster image inside.
If it's a vector-based PDF and its contents are readable it makes more sense to find the table inside contents and just read the text from it instead of doing heavy 'OCR lifting'.
Here's the code for reference for more accurate table recognition:
import os
import imutils
import numpy as np
import argparse
import cv2
def gamma_correction(image, gamma = 1.0):
look_up_table = np.empty((1,256), np.uint8)
for i in range(256):
look_up_table[0,i] = np.clip(pow(i / 255.0, gamma) * 255.0, 0, 255)
result = cv2.LUT(image, look_up_table)
return result
def pre_process_image(image):
# Let's get rid of color first
# Applying gamma to make the table lines darker
gamma = gamma_correction(image, 2)
# Getting rid of color
gray = cv2.cvtColor(gamma, cv2.COLOR_BGR2GRAY)
# Then apply Otsu threshold to reveal important areas
ret, thresh = cv2.threshold(gray, 0, 255, cv2.THRESH_BINARY | cv2.THRESH_OTSU)
# inverting the thresholded image
return ~thresh
def get_horizontal_lines_mask(image, horizontal_size=100):
horizontal = image.copy()
horizontal_structure = cv2.getStructuringElement(cv2.MORPH_RECT, (horizontal_size, 1))
horizontal = cv2.erode(horizontal, horizontal_structure, anchor=(-1, -1), iterations=1)
horizontal = cv2.dilate(horizontal, horizontal_structure, anchor=(-1, -1), iterations=1)
return horizontal
def get_vertical_lines_mask(image, vertical_size=100):
vertical = image.copy()
vertical_structure = cv2.getStructuringElement(cv2.MORPH_RECT, (1, vertical_size))
vertical = cv2.erode(vertical, vertical_structure, anchor=(-1, -1), iterations=1)
vertical = cv2.dilate(vertical, vertical_structure, anchor=(-1, -1), iterations=1)
return vertical
def make_lines_mask(preprocessed, min_horizontal_line_size=100, min_vertical_line_size=100):
hor = get_horizontal_lines_mask(preprocessed, min_horizontal_line_size)
ver = get_vertical_lines_mask(preprocessed, min_vertical_line_size)
mask = np.zeros((preprocessed.shape[0], preprocessed.shape[1], 1), dtype=np.uint8)
mask = cv2.bitwise_or(mask, hor)
mask = cv2.bitwise_or(mask, ver)
return ~mask
def find_cell_boxes(mask):
# Looking for the text spots contours
# OpenCV 3
# img, contours, hierarchy = cv2.findContours(pre, cv2.RETR_LIST, cv2.CHAIN_APPROX_SIMPLE)
# OpenCV 4
contours = cv2.findContours(mask, cv2.RETR_LIST, cv2.CHAIN_APPROX_SIMPLE)
contours = imutils.grab_contours(contours)
contours = sorted(contours, key=cv2.contourArea, reverse=True)
image_width = mask.shape[1]
# Getting the texts bounding boxes based on the text size assumptions
boxes = []
for contour in contours:
box = cv2.boundingRect(contour)
w = box[2]
# Excluding the page box shape but adding smaller boxes
if w < 0.95 * image_width:
boxes.append(box)
return boxes
def find_table_in_boxes(boxes, cell_threshold=10, min_columns=2):
rows = {}
cols = {}
# Clustering the bounding boxes by their positions
for box in boxes:
(x, y, w, h) = box
col_key = x // cell_threshold
row_key = y // cell_threshold
cols[row_key] = [box] if col_key not in cols else cols[col_key] + [box]
rows[row_key] = [box] if row_key not in rows else rows[row_key] + [box]
# Filtering out the clusters having less than 2 cols
table_cells = list(filter(lambda r: len(r) >= min_columns, rows.values()))
# Sorting the row cells by x coord
table_cells = [list(sorted(tb)) for tb in table_cells]
# Sorting rows by the y coord
table_cells = list(sorted(table_cells, key=lambda r: r[0][1]))
return table_cells
def build_vertical_lines(table_cells):
if table_cells is None or len(table_cells) <= 0:
return [], []
max_last_col_width_row = max(table_cells, key=lambda b: b[-1][2])
max_x = max_last_col_width_row[-1][0] + max_last_col_width_row[-1][2]
max_last_row_height_box = max(table_cells[-1], key=lambda b: b[3])
max_y = max_last_row_height_box[1] + max_last_row_height_box[3]
hor_lines = []
ver_lines = []
for box in table_cells:
x = box[0][0]
y = box[0][1]
hor_lines.append((x, y, max_x, y))
for box in table_cells[0]:
x = box[0]
y = box[1]
ver_lines.append((x, y, x, max_y))
(x, y, w, h) = table_cells[0][-1]
ver_lines.append((max_x, y, max_x, max_y))
(x, y, w, h) = table_cells[0][0]
hor_lines.append((x, max_y, max_x, max_y))
return hor_lines, ver_lines
if __name__ == "__main__":
ap = argparse.ArgumentParser()
ap.add_argument("-i", "--image", required=True, help="path to images directory")
args = vars(ap.parse_args())
in_file = args["image"]
filename_base = in_file.replace(os.path.splitext(in_file)[1], "")
img = cv2.imread(in_file)
pre_processed = pre_process_image(img)
# Visualizing pre-processed image
cv2.imwrite(filename_base + ".pre.png", pre_processed)
lines_mask = make_lines_mask(pre_processed, min_horizontal_line_size=1800, min_vertical_line_size=500)
# Visualizing table lines mask
cv2.imwrite(filename_base + ".mask.png", lines_mask)
cell_boxes = find_cell_boxes(lines_mask)
cells = find_table_in_boxes(cell_boxes)
# apply OCR to each cell rect here
# the cells array contains cell coordinates in tuples (x, y, w, h)
hor_lines, ver_lines = build_vertical_lines(cells)
# Visualize the table lines
vis = img.copy()
for line in hor_lines:
[x1, y1, x2, y2] = line
cv2.line(vis, (x1, y1), (x2, y2), (0, 0, 255), 1)
for line in ver_lines:
[x1, y1, x2, y2] = line
cv2.line(vis, (x1, y1), (x2, y2), (0, 0, 255), 1)
cv2.imwrite(filename_base + ".result.png", vis)
Some parameters are hard-coded:
page size threshold - 0.95
min horizontal line size - 1800 px
min vertical line size - 500 px
You can provide them as configurable parameters or make them relative to image size.
Results:
I think that the best way to do what you need is to find and isolate the cells in the file and then apply OCR to each individual cell.
There are a number of solutions in SO for that, I got the code from this answer and played around a little with the parameters to get the output below (not perfect yet, but you can tweak it a little bit yourself).
import os
import cv2
import imutils
# This only works if there's only one table on a page
# Important parameters:
# - morph_size
# - min_text_height_limit
# - max_text_height_limit
# - cell_threshold
# - min_columns
def pre_process_image(img, save_in_file, morph_size=(23, 23)):
# get rid of the color
pre = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
# Otsu threshold
pre = cv2.threshold(pre, 250, 255, cv2.THRESH_BINARY | cv2.THRESH_OTSU)[1]
# dilate the text to make it solid spot
cpy = pre.copy()
struct = cv2.getStructuringElement(cv2.MORPH_RECT, morph_size)
cpy = cv2.dilate(~cpy, struct, anchor=(-1, -1), iterations=1)
pre = ~cpy
if save_in_file is not None:
cv2.imwrite(save_in_file, pre)
return pre
def find_text_boxes(pre, min_text_height_limit=20, max_text_height_limit=120):
# Looking for the text spots contours
contours, _ = cv2.findContours(pre, cv2.RETR_LIST, cv2.CHAIN_APPROX_SIMPLE)
# Getting the texts bounding boxes based on the text size assumptions
boxes = []
for contour in contours:
box = cv2.boundingRect(contour)
h = box[3]
if min_text_height_limit < h < max_text_height_limit:
boxes.append(box)
return boxes
def find_table_in_boxes(boxes, cell_threshold=100, min_columns=3):
rows = {}
cols = {}
# Clustering the bounding boxes by their positions
for box in boxes:
(x, y, w, h) = box
col_key = x // cell_threshold
row_key = y // cell_threshold
cols[row_key] = [box] if col_key not in cols else cols[col_key] + [box]
rows[row_key] = [box] if row_key not in rows else rows[row_key] + [box]
# Filtering out the clusters having less than 2 cols
table_cells = list(filter(lambda r: len(r) >= min_columns, rows.values()))
# Sorting the row cells by x coord
table_cells = [list(sorted(tb)) for tb in table_cells]
# Sorting rows by the y coord
table_cells = list(sorted(table_cells, key=lambda r: r[0][1]))
return table_cells
def build_lines(table_cells):
if table_cells is None or len(table_cells) <= 0:
return [], []
max_last_col_width_row = max(table_cells, key=lambda b: b[-1][2])
max_x = max_last_col_width_row[-1][0] + max_last_col_width_row[-1][2]
max_last_row_height_box = max(table_cells[-1], key=lambda b: b[3])
max_y = max_last_row_height_box[1] + max_last_row_height_box[3]
hor_lines = []
ver_lines = []
for box in table_cells:
x = box[0][0]
y = box[0][1]
hor_lines.append((x, y, max_x, y))
for box in table_cells[0]:
x = box[0]
y = box[1]
ver_lines.append((x, y, x, max_y))
(x, y, w, h) = table_cells[0][-1]
ver_lines.append((max_x, y, max_x, max_y))
(x, y, w, h) = table_cells[0][0]
hor_lines.append((x, max_y, max_x, max_y))
return hor_lines, ver_lines
if __name__ == "__main__":
in_file = os.path.join(".", "test.jpg")
pre_file = os.path.join(".", "pre.png")
out_file = os.path.join(".", "out.png")
img = cv2.imread(os.path.join(in_file))
pre_processed = pre_process_image(img, pre_file)
text_boxes = find_text_boxes(pre_processed)
cells = find_table_in_boxes(text_boxes)
hor_lines, ver_lines = build_lines(cells)
# Visualize the result
vis = img.copy()
# for box in text_boxes:
# (x, y, w, h) = box
# cv2.rectangle(vis, (x, y), (x + w - 2, y + h - 2), (0, 255, 0), 1)
for line in hor_lines:
[x1, y1, x2, y2] = line
cv2.line(vis, (x1, y1), (x2, y2), (0, 0, 255), 1)
for line in ver_lines:
[x1, y1, x2, y2] = line
cv2.line(vis, (x1, y1), (x2, y2), (0, 0, 255), 1)
cv2.imwrite(out_file, vis)

OpenCV: Segment each digit from the given image. Digits are written in each cell of a row matrix. Each cell is bounded by margins

I have been trying to recognise handwritten letters (digits/alphabet) from a form-document. As it is known that form-documents have 1d row cells, where the applicant has to fill their information within those bounded cells. However, I'm unable to segment the digits(currently my input consists only digits) from the bounding boxes.
I went through the following steps:
Reading the image (as a grayscale image) via "imread" method of opencv2. Initial Image size:19 x 209(in pixels).
pic = "crop/cropped000.jpg"
newImg = cv2.imread(pic, 0)
Resizing the image 200% its original size via "resize" method of opencv2. I used INTER_AREA Interpolation. Resized Image size: 38 x 418(in pixels)
h,w = newImg.shape
resizedImg = cv2.resize(newImg, (2*w,2*h), interpolation=cv2.INTER_AREA)
Applied Canny edge detection.
v = np.median(resizedImg)
sigma = 0.33
lower = int(max(0, (1.0 - sigma) * v))
upper = int(min(255, (1.0 + sigma) * v))
edgedImg = cv2.Canny(resizedImg, lower, upper)
Cropped the contours and saved them as images in 'BB' directory.
im2, contours, hierarchy = cv2.findContours(edgedImg.copy(),cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE)
num = 0
for c in contours:
x, y, w, h = cv2.boundingRect(c)
num += 1
new_img = resizedImg[y:y+h, x:x+w]
cv2.imwrite('BB/'+str(num).zfill(3) + '.jpg', new_img)
Entire code in summary:
pic = "crop/cropped000.jpg"
newImg = cv2.imread(pic, 0)
h,w = newImg.shape
print(newImg.shape)
resizedImg = cv2.resize(newImg, (2*w,2*h), interpolation=cv2.INTER_AREA)
print(resizedImg.shape)
v = np.median(resizedImg)
sigma = 0.33
lower = int(max(0, (1.0 - sigma) * v))
upper = int(min(255, (1.0 + sigma) * v))
edgedImg = cv2.Canny(resizedImg, lower, upper)
im2, contours, hierarchy = cv2.findContours(edgedImg.copy(),cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE)
num = 0
for c in contours:
x, y, w, h = cv2.boundingRect(c)
num += 1
new_img = resizedImg[y:y+h, x:x+w]
cv2.imwrite('BB/'+str(num).zfill(3) + '.jpg', new_img)
Images produced are posted here:
https://imgur.com/a/GStIcdj
I had to double the image size because Canny edge detection was producing double-edges for an object (However, it still does). I have also played with other openCV functionalities like Thresholding, Gaussian Blur, Dilate, Erode but all in vain.
# we need one more parameter for Date cell width : as this could be different for diff bank
def crop_image_data_from_date_field(image, new_start_h, new_end_h, new_start_w, new_end_w, cell_width):
#for date each cell has same height and width : here width: 25 px so cord will be changed based on width
cropped_image_list = []
starting_width = new_start_w
for i in range(1,9): # as date has only 8 fields: DD/MM/YYYY
cropped_img = image[new_start_h:new_end_h, new_start_w + 1 :new_start_w+22]
new_start_w = starting_width + (i*cell_width)
cropped_img = cv2.resize(cropped_img, (28, 28))
image_name = 'cropped_date/cropped_'+ str(i) + '.png'
cv2.imwrite(image_name, cropped_img)
cropped_image_list.append(image_name)
# print('cropped_image_list : ',cropped_image_list,len(cropped_image_list))
# rec_value = handwritten_digit_recog.recog_digits(cropped_image_list)
recvd_value = custom_predict.predict_digit(cropped_image_list)
# print('recvd val : ',recvd_value)
return recvd_value
you need to specify each cell width and it's x,y,w,h.
I think this will help you.

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