I have a collection of images as below -
Example 1
Example 2
Example 3
These represent dates in DDMMYYYY format. For each of these images, I want to save each digit as a separate image.For example 1, I wish to save 7,9,0,8,5,8,7,1 as separate images sliced from the original image. So far, I have tried various methods described on different stackoverflow & blogposts but none of them seems to work.
Code to extract boxes surrounding dates -
from glob import glob
import cv2 as cv
import numpy as np
from tqdm import tqdm
class ExtractRectangle:
def __init__(self):
super().__init__()
self.minLinLength_h = 70
self.minLinLength_v = 5
self.maxLineGap = 20
def is_horizontal(self, line, thresh=5):
return abs(line[1] - line[3]) <= thresh
def is_vertical(self, line, thresh=5):
return abs(line[0] - line[2]) <= thresh
def get_lines(self, canny, horizontal=True):
lines = []
if horizontal:
linesP = cv.HoughLinesP(
canny,
rho=1,
theta=np.pi / 180,
threshold=10,
lines=None,
minLineLength=self.minLinLength_h,
maxLineGap=20,
)
else:
linesP = cv.HoughLinesP(
canny,
rho=1,
theta=np.pi / 180,
threshold=10,
lines=None,
minLineLength=self.minLinLength_v,
maxLineGap=20,
)
if linesP is not None:
for i in range(0, len(linesP)):
l = linesP[i][0]
if self.is_horizontal(l, 3) and horizontal:
lines.append(l)
elif self.is_vertical(l, 3):
lines.append(l)
return lines
def remove_whitespace(self, img):
# https://stackoverflow.com/questions/48395434/how-to-crop-or-remove-white-background-from-an-image
gray = cv.cvtColor(img, cv.COLOR_BGR2GRAY)
th, threshed = cv.threshold(gray, 127, 255, cv.THRESH_BINARY_INV)
kernel = cv.getStructuringElement(cv.MORPH_ELLIPSE, (11, 11))
morphed = cv.morphologyEx(threshed, cv.MORPH_CLOSE, kernel)
cnts = cv.findContours(morphed, cv.RETR_EXTERNAL, cv.CHAIN_APPROX_SIMPLE)[-2]
cnt = sorted(cnts, key=cv.contourArea)[-1]
x, y, w, h = cv.boundingRect(cnt)
dst = img[y : y + h, x : x + w]
return dst
def process_image(self, filename, path):
errenous = False
img = cv.imread(cv.samples.findFile(filename))
img = self.remove_whitespace(img)
cImage = np.copy(img)
gray = cv.cvtColor(img, cv.COLOR_BGR2GRAY)
canny = cv.Canny(gray, 100, 200)
horizontal_lines = self.get_lines(canny)
horizontal_lines = sorted(horizontal_lines, key=lambda a_entry: a_entry[..., 1])
vertical_lines = self.get_lines(canny, horizontal=False)
vertical_lines = sorted(vertical_lines, key=lambda a_entry: a_entry[..., 0])
if len(horizontal_lines) > 0:
initial_line = horizontal_lines[0]
final_line = horizontal_lines[-1]
# LeftTop(x1, y1) -> RightTop(x2, y1) -> RightBottom(x2, y2) -> LeftBottom(x1, y2)
y1 = initial_line[1]
y2 = final_line[1]
bottom = min(y1, y2)
top = max(y1, y2)
# post whitespace removal, dates should only be the major component
if (top-bottom) / img.shape[0] < 0.6:
errenous = True
else:
errenous = True
if len(vertical_lines) > 0:
initial_line = vertical_lines[0]
final_line = vertical_lines[-1]
x1 = initial_line[0]
x2 = final_line[0]
left = min(x1, x2)
right = max(x1, x2)
# as dates occupy majority of the horizontal space
if (right-left) / img.shape[1] < 0.95:
errenous = True
else:
errenous = True
if not errenous:
# cImage = cv.rectangle(cImage, (left, bottom), (right, top), (255, 0, 0), 2)
cImage = cImage[
bottom : bottom + (top - bottom), left : left + (right - left)
]
cv.imwrite(f"{path}/{filename.split('/')[-1]}", cImage)
if __name__ == "__main__":
extract = ExtractRectangle()
test_files = glob("data/raw/test/*.png")
test_path = "data/processed/test/"
for path in tqdm(test_files):
extract.process_image(path, test_path)
train_files = glob("data/raw/train/*.png")
train_path = "data/processed/train/"
for path in tqdm(train_files):
extract.process_image(path, train_path)
Resultant detection for above images -
Example 1
Example 2
Example 3
Some other samples
I'm getting module not found error while executing my program.
import numpy as np
import cv2
from preprocessors import x_cord_contour, makeSquare, resize_to_pixel
I am quite sure that you are following along the the Deep Learning course by Rajeev D. And I further guess that you haven't downloaded the VM image as suggested in the video.
The functions x_cord_contour, makeSquare and resize_to_pixel are defined in a custom module. If you are following the course without the VM just copy and paste the functions below into your code and remove the import statement.
import numpy as np
import cv2
def x_cord_contour(contour):
# This function take a contour from findContours
# it then outputs the x centroid coordinates
M = cv2.moments(contour)
return (int(M['m10']/M['m00']))
def makeSquare(not_square):
# This function takes an image and makes the dimenions square
# It adds black pixels as the padding where needed
BLACK = [0,0,0]
img_dim = not_square.shape
height = img_dim[0]
width = img_dim[1]
#print("Height = ", height, "Width = ", width)
if (height == width):
square = not_square
return square
else:
doublesize = cv2.resize(not_square,(2*width, 2*height), interpolation = cv2.INTER_CUBIC)
height = height * 2
width = width * 2
#print("New Height = ", height, "New Width = ", width)
if (height > width):
pad = int((height - width)/2)
#print("Padding = ", pad)
doublesize_square = cv2.copyMakeBorder(doublesize,0,0,pad,pad,cv2.BORDER_CONSTANT,value=BLACK)
else:
pad = (width - height)/2
#print("Padding = ", pad)
doublesize_square = cv2.copyMakeBorder(doublesize,pad,pad,0,0,\
cv2.BORDER_CONSTANT,value=BLACK)
doublesize_square_dim = doublesize_square.shape
#print("Sq Height = ", doublesize_square_dim[0], "Sq Width = ", doublesize_square_dim[1])
return doublesize_square
def resize_to_pixel(dimensions, image):
# This function then re-sizes an image to the specificied dimenions
buffer_pix = 4
dimensions = dimensions - buffer_pix
squared = image
r = float(dimensions) / squared.shape[1]
dim = (dimensions, int(squared.shape[0] * r))
resized = cv2.resize(image, dim, interpolation = cv2.INTER_AREA)
img_dim2 = resized.shape
height_r = img_dim2[0]
width_r = img_dim2[1]
BLACK = [0,0,0]
if (height_r > width_r):
resized = cv2.copyMakeBorder(resized,0,0,0,1,cv2.BORDER_CONSTANT,value=BLACK)
if (height_r < width_r):
resized = cv2.copyMakeBorder(resized,1,0,0,0,cv2.BORDER_CONSTANT,value=BLACK)
p = 2
ReSizedImg = cv2.copyMakeBorder(resized,p,p,p,p,cv2.BORDER_CONSTANT,value=BLACK)
img_dim = ReSizedImg.shape
height = img_dim[0]
width = img_dim[1]
#print("Padded Height = ", height, "Width = ", width)
return ReSizedImg
I am trying to horizontally combine some JPEG images in Python.
Problem
I have 3 images - each is 148 x 95 - see attached. I just made 3 copies of the same image - that is why they are the same.
My attempt
I am trying to horizontally join them using the following code:
import sys
from PIL import Image
list_im = ['Test1.jpg','Test2.jpg','Test3.jpg']
# creates a new empty image, RGB mode, and size 444 by 95
new_im = Image.new('RGB', (444,95))
for elem in list_im:
for i in xrange(0,444,95):
im=Image.open(elem)
new_im.paste(im, (i,0))
new_im.save('test.jpg')
However, this is producing the output attached as test.jpg.
Question
Is there a way to horizontally concatenate these images such that the sub-images in test.jpg do not have an extra partial image showing?
Additional Information
I am looking for a way to horizontally concatenate n images. I would like to use this code generally so I would prefer to:
not to hard-code image dimensions, if possible
specify dimensions in one line so that they can be easily changed
You can do something like this:
import sys
from PIL import Image
images = [Image.open(x) for x in ['Test1.jpg', 'Test2.jpg', 'Test3.jpg']]
widths, heights = zip(*(i.size for i in images))
total_width = sum(widths)
max_height = max(heights)
new_im = Image.new('RGB', (total_width, max_height))
x_offset = 0
for im in images:
new_im.paste(im, (x_offset,0))
x_offset += im.size[0]
new_im.save('test.jpg')
Test1.jpg
Test2.jpg
Test3.jpg
test.jpg
The nested for for i in xrange(0,444,95): is pasting each image 5 times, staggered 95 pixels apart. Each outer loop iteration pasting over the previous.
for elem in list_im:
for i in xrange(0,444,95):
im=Image.open(elem)
new_im.paste(im, (i,0))
new_im.save('new_' + elem + '.jpg')
I would try this:
import numpy as np
import PIL
from PIL import Image
list_im = ['Test1.jpg', 'Test2.jpg', 'Test3.jpg']
imgs = [ Image.open(i) for i in list_im ]
# pick the image which is the smallest, and resize the others to match it (can be arbitrary image shape here)
min_shape = sorted( [(np.sum(i.size), i.size ) for i in imgs])[0][1]
imgs_comb = np.hstack([i.resize(min_shape) for i in imgs])
# save that beautiful picture
imgs_comb = Image.fromarray( imgs_comb)
imgs_comb.save( 'Trifecta.jpg' )
# for a vertical stacking it is simple: use vstack
imgs_comb = np.vstack([i.resize(min_shape) for i in imgs])
imgs_comb = Image.fromarray( imgs_comb)
imgs_comb.save( 'Trifecta_vertical.jpg' )
It should work as long as all images are of the same variety (all RGB, all RGBA, or all grayscale). It shouldn't be difficult to ensure this is the case with a few more lines of code. Here are my example images, and the result:
Test1.jpg
Test2.jpg
Test3.jpg
Trifecta.jpg:
Trifecta_vertical.jpg
Edit: DTing's answer is more applicable to your question since it uses PIL, but I'll leave this up in case you want to know how to do it in numpy.
Here is a numpy/matplotlib solution that should work for N images (only color images) of any size/shape.
import numpy as np
import matplotlib.pyplot as plt
def concat_images(imga, imgb):
"""
Combines two color image ndarrays side-by-side.
"""
ha,wa = imga.shape[:2]
hb,wb = imgb.shape[:2]
max_height = np.max([ha, hb])
total_width = wa+wb
new_img = np.zeros(shape=(max_height, total_width, 3))
new_img[:ha,:wa]=imga
new_img[:hb,wa:wa+wb]=imgb
return new_img
def concat_n_images(image_path_list):
"""
Combines N color images from a list of image paths.
"""
output = None
for i, img_path in enumerate(image_path_list):
img = plt.imread(img_path)[:,:,:3]
if i==0:
output = img
else:
output = concat_images(output, img)
return output
Here is example use:
>>> images = ["ronda.jpeg", "rhod.jpeg", "ronda.jpeg", "rhod.jpeg"]
>>> output = concat_n_images(images)
>>> import matplotlib.pyplot as plt
>>> plt.imshow(output)
>>> plt.show()
Here is a function generalizing previous approaches, creating a grid of images in PIL:
from PIL import Image
import numpy as np
def pil_grid(images, max_horiz=np.iinfo(int).max):
n_images = len(images)
n_horiz = min(n_images, max_horiz)
h_sizes, v_sizes = [0] * n_horiz, [0] * (n_images // n_horiz)
for i, im in enumerate(images):
h, v = i % n_horiz, i // n_horiz
h_sizes[h] = max(h_sizes[h], im.size[0])
v_sizes[v] = max(v_sizes[v], im.size[1])
h_sizes, v_sizes = np.cumsum([0] + h_sizes), np.cumsum([0] + v_sizes)
im_grid = Image.new('RGB', (h_sizes[-1], v_sizes[-1]), color='white')
for i, im in enumerate(images):
im_grid.paste(im, (h_sizes[i % n_horiz], v_sizes[i // n_horiz]))
return im_grid
It will shrink each row and columns of the grid to the minimum. You can have only a row by using pil_grid(images), or only a column by using pil_grid(images, 1).
One benefit of using PIL over numpy-array based solutions is that you can deal with images structured differently (like grayscale or palette-based images).
Example outputs
def dummy(w, h):
"Produces a dummy PIL image of given dimensions"
from PIL import ImageDraw
im = Image.new('RGB', (w, h), color=tuple((np.random.rand(3) * 255).astype(np.uint8)))
draw = ImageDraw.Draw(im)
points = [(i, j) for i in (0, im.size[0]) for j in (0, im.size[1])]
for i in range(len(points) - 1):
for j in range(i+1, len(points)):
draw.line(points[i] + points[j], fill='black', width=2)
return im
dummy_images = [dummy(20 + np.random.randint(30), 20 + np.random.randint(30)) for _ in range(10)]
pil_grid(dummy_images):
pil_grid(dummy_images, 3):
pil_grid(dummy_images, 1):
Based on DTing's answer I created a function that is easier to use:
from PIL import Image
def append_images(images, direction='horizontal',
bg_color=(255,255,255), aligment='center'):
"""
Appends images in horizontal/vertical direction.
Args:
images: List of PIL images
direction: direction of concatenation, 'horizontal' or 'vertical'
bg_color: Background color (default: white)
aligment: alignment mode if images need padding;
'left', 'right', 'top', 'bottom', or 'center'
Returns:
Concatenated image as a new PIL image object.
"""
widths, heights = zip(*(i.size for i in images))
if direction=='horizontal':
new_width = sum(widths)
new_height = max(heights)
else:
new_width = max(widths)
new_height = sum(heights)
new_im = Image.new('RGB', (new_width, new_height), color=bg_color)
offset = 0
for im in images:
if direction=='horizontal':
y = 0
if aligment == 'center':
y = int((new_height - im.size[1])/2)
elif aligment == 'bottom':
y = new_height - im.size[1]
new_im.paste(im, (offset, y))
offset += im.size[0]
else:
x = 0
if aligment == 'center':
x = int((new_width - im.size[0])/2)
elif aligment == 'right':
x = new_width - im.size[0]
new_im.paste(im, (x, offset))
offset += im.size[1]
return new_im
It allows choosing a background color and image alignment. It's also easy to do recursion:
images = map(Image.open, ['hummingbird.jpg', 'tiger.jpg', 'monarch.png'])
combo_1 = append_images(images, direction='horizontal')
combo_2 = append_images(images, direction='horizontal', aligment='top',
bg_color=(220, 140, 60))
combo_3 = append_images([combo_1, combo_2], direction='vertical')
combo_3.save('combo_3.png')
If all image's heights are same,
import numpy as np
imgs = ['a.jpg', 'b.jp', 'c.jpg']
concatenated = Image.fromarray(
np.concatenate(
[np.array(Image.open(x)) for x in imgs],
axis=1
)
)
Maybe you can resize images before the concatenation like this,
import numpy as np
imgs = ['a.jpg', 'b.jpg', 'c.jpg']
concatenated = Image.fromarray(
np.concatenate(
[np.array(Image.open(x).resize((640,480)) for x in imgs],
axis=1
)
)
Here's my solution:
from PIL import Image
def join_images(*rows, bg_color=(0, 0, 0, 0), alignment=(0.5, 0.5)):
rows = [
[image.convert('RGBA') for image in row]
for row
in rows
]
heights = [
max(image.height for image in row)
for row
in rows
]
widths = [
max(image.width for image in column)
for column
in zip(*rows)
]
tmp = Image.new(
'RGBA',
size=(sum(widths), sum(heights)),
color=bg_color
)
for i, row in enumerate(rows):
for j, image in enumerate(row):
y = sum(heights[:i]) + int((heights[i] - image.height) * alignment[1])
x = sum(widths[:j]) + int((widths[j] - image.width) * alignment[0])
tmp.paste(image, (x, y))
return tmp
def join_images_horizontally(*row, bg_color=(0, 0, 0), alignment=(0.5, 0.5)):
return join_images(
row,
bg_color=bg_color,
alignment=alignment
)
def join_images_vertically(*column, bg_color=(0, 0, 0), alignment=(0.5, 0.5)):
return join_images(
*[[image] for image in column],
bg_color=bg_color,
alignment=alignment
)
For these images:
images = [
[Image.open('banana.png'), Image.open('apple.png')],
[Image.open('lime.png'), Image.open('lemon.png')],
]
Results will look like:
join_images(
*images,
bg_color='green',
alignment=(0.5, 0.5)
).show()
join_images(
*images,
bg_color='green',
alignment=(0, 0)
).show()
join_images(
*images,
bg_color='green',
alignment=(1, 1)
).show()
There is also skimage.util.montage to create a montage of images of the same shape:
import numpy as np
import PIL
from PIL import Image
from skimage.util import montage
list_im = ['Test1.jpg', 'Test2.jpg', 'Test3.jpg']
imgs = [ np.array(Image.open(i)) for i in list_im ]
montage(imgs)
"""
merge_image takes three parameters first two parameters specify
the two images to be merged and third parameter i.e. vertically
is a boolean type which if True merges images vertically
and finally saves and returns the file_name
"""
def merge_image(img1, img2, vertically):
images = list(map(Image.open, [img1, img2]))
widths, heights = zip(*(i.size for i in images))
if vertically:
max_width = max(widths)
total_height = sum(heights)
new_im = Image.new('RGB', (max_width, total_height))
y_offset = 0
for im in images:
new_im.paste(im, (0, y_offset))
y_offset += im.size[1]
else:
total_width = sum(widths)
max_height = max(heights)
new_im = Image.new('RGB', (total_width, max_height))
x_offset = 0
for im in images:
new_im.paste(im, (x_offset, 0))
x_offset += im.size[0]
new_im.save('test.jpg')
return 'test.jpg'
from __future__ import print_function
import os
from pil import Image
files = [
'1.png',
'2.png',
'3.png',
'4.png']
result = Image.new("RGB", (800, 800))
for index, file in enumerate(files):
path = os.path.expanduser(file)
img = Image.open(path)
img.thumbnail((400, 400), Image.ANTIALIAS)
x = index // 2 * 400
y = index % 2 * 400
w, h = img.size
result.paste(img, (x, y, x + w, y + h))
result.save(os.path.expanduser('output.jpg'))
Output
Just adding to the solutions already suggested. Assumes same height, no resizing.
import sys
import glob
from PIL import Image
Image.MAX_IMAGE_PIXELS = 100000000 # For PIL Image error when handling very large images
imgs = [ Image.open(i) for i in list_im ]
widths, heights = zip(*(i.size for i in imgs))
total_width = sum(widths)
max_height = max(heights)
new_im = Image.new('RGB', (total_width, max_height))
# Place first image
new_im.paste(imgs[0],(0,0))
# Iteratively append images in list horizontally
hoffset=0
for i in range(1,len(imgs),1):
**hoffset=imgs[i-1].size[0]+hoffset # update offset**
new_im.paste(imgs[i],**(hoffset,0)**)
new_im.save('output_horizontal_montage.jpg')
my solution would be :
import sys
import os
from PIL import Image, ImageFilter
from PIL import ImageFont
from PIL import ImageDraw
os.chdir('C:/Users/Sidik/Desktop/setup')
print(os.getcwd())
image_list= ['IMG_7292.jpg','IMG_7293.jpg','IMG_7294.jpg', 'IMG_7295.jpg' ]
image = [Image.open(x) for x in image_list] # list
im_1 = image[0].rotate(270)
im_2 = image[1].rotate(270)
im_3 = image[2].rotate(270)
#im_4 = image[3].rotate(270)
height = image[0].size[0]
width = image[0].size[1]
# Create an empty white image frame
new_im = Image.new('RGB',(height*2,width*2),(255,255,255))
new_im.paste(im_1,(0,0))
new_im.paste(im_2,(height,0))
new_im.paste(im_3,(0,width))
new_im.paste(im_4,(height,width))
draw = ImageDraw.Draw(new_im)
font = ImageFont.truetype('arial',200)
draw.text((0, 0), '(a)', fill='white', font=font)
draw.text((height, 0), '(b)', fill='white', font=font)
draw.text((0, width), '(c)', fill='white', font=font)
#draw.text((height, width), '(d)', fill='white', font=font)
new_im.show()
new_im.save('BS1319.pdf')
[![Laser spots on the edge][1]][1]
#**How to merge cropped images back to original image**
images = [Image.open(x) for x in images_list]
print("Length:: ", len(images))
widths, heights = zip(*(i.size for i in images))
print(widths, heights)
total_width = sum(widths)
max_height = sum(heights)
print(total_width,max_height)
new_im = Image.new('RGB', (5*384, 5*216))
x_offset = 0
y_offset = 0
img_size = [384,216]
def grouped(iterable, n):
return zip(*[iter(iterable)]*n)
for x,y,a,b,c in grouped(images, 5):
temp = []
temp.append([x,y,a,b,c])
print(temp[0])
print(len(temp[0]))
for lsingle_img in temp[0]:
# print(lsingle_img)
print("x_y_offset: ", (x_offset, y_offset))
new_im.paste(lsingle_img, (x_offset, y_offset))
x_offset += img_size[0]
temp = []
x_offset = 0
y_offset += img_size[1]
new_im.save('test.jpg')