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59 lines
1.9 KiB
Python
59 lines
1.9 KiB
Python
'''
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Text skewness correction
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This tutorial demonstrates how to correct the skewness in a text.
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The program takes as input a skewed source image and shows non skewed text.
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Usage:
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python text_skewness_correction.py --image "Image path"
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'''
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import numpy as np
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import cv2 as cv
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import sys
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import argparse
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def main():
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parser = argparse.ArgumentParser()
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parser.add_argument("-i", "--image", required=True, help="path to input image file")
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args = vars(parser.parse_args())
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# load the image from disk
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image = cv.imread(cv.samples.findFile(args["image"]))
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if image is None:
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print("can't read image " + args["image"])
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sys.exit(-1)
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gray = cv.cvtColor(image, cv.COLOR_BGR2GRAY)
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# threshold the image, setting all foreground pixels to
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# 255 and all background pixels to 0
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thresh = cv.threshold(gray, 0, 255, cv.THRESH_BINARY_INV | cv.THRESH_OTSU)[1]
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# Applying erode filter to remove random noise
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erosion_size = 1
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element = cv.getStructuringElement(cv.MORPH_RECT, (2 * erosion_size + 1, 2 * erosion_size + 1), (erosion_size, erosion_size) )
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thresh = cv.erode(thresh, element)
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coords = cv.findNonZero(thresh)
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angle = cv.minAreaRect(coords)[-1]
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# the `cv.minAreaRect` function returns values in the
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# range [-90, 0) if the angle is less than -45 we need to add 90 to it
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if angle < -45:
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angle = (90 + angle)
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(h, w) = image.shape[:2]
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center = (w // 2, h // 2)
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M = cv.getRotationMatrix2D(center, angle, 1.0)
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rotated = cv.warpAffine(image, M, (w, h), flags=cv.INTER_CUBIC, borderMode=cv.BORDER_REPLICATE)
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cv.putText(rotated, "Angle: {:.2f} degrees".format(angle), (10, 30), cv.FONT_HERSHEY_SIMPLEX, 0.7, (0, 0, 255), 2)
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# show the output image
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print("[INFO] angle: {:.2f}".format(angle))
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cv.imshow("Input", image)
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cv.imshow("Rotated", rotated)
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cv.waitKey(0)
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if __name__ == "__main__":
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main()
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