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Merge pull request #9406 from Cartucho:update_core_tutorials

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This commit is contained in:
Vadim Pisarevsky
2017-09-13 14:09:39 +00:00
parent f1aa180a40 45afd29b72
commit bc09d1ba3b
16 changed files with 1107 additions and 265 deletions
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samples/python/tutorial_code/core/AddingImages/adding_images.py
+35
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@@ -0,0 +1,35 @@
from __future__ import print_function
import sys
import cv2
alpha = 0.5
print(''' Simple Linear Blender
-----------------------
* Enter alpha [0.0-1.0]: ''')
if sys.version_info >= (3, 0): # If Python 3.x
input_alpha = float(input())
else:
input_alpha = float(raw_input())
if 0 <= alpha <= 1:
alpha = input_alpha
## [load]
src1 = cv2.imread('../../../../data/LinuxLogo.jpg')
src2 = cv2.imread('../../../../data/WindowsLogo.jpg')
## [load]
if src1 is None:
print ("Error loading src1")
exit(-1)
elif src2 is None:
print ("Error loading src2")
exit(-1)
## [blend_images]
beta = (1.0 - alpha)
dst = cv2.addWeighted(src1, alpha, src2, beta, 0.0)
## [blend_images]
## [display]
cv2.imshow('dst', dst)
cv2.waitKey(0)
## [display]
cv2.destroyAllWindows()
samples/python/tutorial_code/core/BasicGeometricDrawing/basic_geometric_drawing.py
+115
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@@ -0,0 +1,115 @@
import cv2
import numpy as np
W = 400
## [my_ellipse]
def my_ellipse(img, angle):
thickness = 2
line_type = 8
cv2.ellipse(img,
(W / 2, W / 2),
(W / 4, W / 16),
angle,
0,
360,
(255, 0, 0),
thickness,
line_type)
## [my_ellipse]
## [my_filled_circle]
def my_filled_circle(img, center):
thickness = -1
line_type = 8
cv2.circle(img,
center,
W / 32,
(0, 0, 255),
thickness,
line_type)
## [my_filled_circle]
## [my_polygon]
def my_polygon(img):
line_type = 8
# Create some points
ppt = np.array([[W / 4, 7 * W / 8], [3 * W / 4, 7 * W / 8],
[3 * W / 4, 13 * W / 16], [11 * W / 16, 13 * W / 16],
[19 * W / 32, 3 * W / 8], [3 * W / 4, 3 * W / 8],
[3 * W / 4, W / 8], [26 * W / 40, W / 8],
[26 * W / 40, W / 4], [22 * W / 40, W / 4],
[22 * W / 40, W / 8], [18 * W / 40, W / 8],
[18 * W / 40, W / 4], [14 * W / 40, W / 4],
[14 * W / 40, W / 8], [W / 4, W / 8],
[W / 4, 3 * W / 8], [13 * W / 32, 3 * W / 8],
[5 * W / 16, 13 * W / 16], [W / 4, 13 * W / 16]], np.int32)
ppt = ppt.reshape((-1, 1, 2))
cv2.fillPoly(img, [ppt], (255, 255, 255), line_type)
# Only drawind the lines would be:
# cv2.polylines(img, [ppt], True, (255, 0, 255), line_type)
## [my_polygon]
## [my_line]
def my_line(img, start, end):
thickness = 2
line_type = 8
cv2.line(img,
start,
end,
(0, 0, 0),
thickness,
line_type)
## [my_line]
## [create_images]
# Windows names
atom_window = "Drawing 1: Atom"
rook_window = "Drawing 2: Rook"
# Create black empty images
size = W, W, 3
atom_image = np.zeros(size, dtype=np.uint8)
rook_image = np.zeros(size, dtype=np.uint8)
## [create_images]
## [draw_atom]
# 1. Draw a simple atom:
# -----------------------
# 1.a. Creating ellipses
my_ellipse(atom_image, 90)
my_ellipse(atom_image, 0)
my_ellipse(atom_image, 45)
my_ellipse(atom_image, -45)
# 1.b. Creating circles
my_filled_circle(atom_image, (W / 2, W / 2))
## [draw_atom]
## [draw_rook]
# 2. Draw a rook
# ------------------
# 2.a. Create a convex polygon
my_polygon(rook_image)
## [rectangle]
# 2.b. Creating rectangles
cv2.rectangle(rook_image,
(0, 7 * W / 8),
(W, W),
(0, 255, 255),
-1,
8)
## [rectangle]
# 2.c. Create a few lines
my_line(rook_image, (0, 15 * W / 16), (W, 15 * W / 16))
my_line(rook_image, (W / 4, 7 * W / 8), (W / 4, W))
my_line(rook_image, (W / 2, 7 * W / 8), (W / 2, W))
my_line(rook_image, (3 * W / 4, 7 * W / 8), (3 * W / 4, W))
## [draw_rook]
cv2.imshow(atom_window, atom_image)
cv2.moveWindow(atom_window, 0, 200)
cv2.imshow(rook_window, rook_image)
cv2.moveWindow(rook_window, W, 200)
cv2.waitKey(0)
cv2.destroyAllWindows()
samples/python/tutorial_code/core/discrete_fourier_transform/discrete_fourier_transform.py
+80
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@@ -0,0 +1,80 @@
from __future__ import print_function
import sys
import cv2
import numpy as np
def print_help():
print('''
This program demonstrated the use of the discrete Fourier transform (DFT).
The dft of an image is taken and it's power spectrum is displayed.
Usage:
discrete_fourier_transform.py [image_name -- default ../../../../data/lena.jpg]''')
def main(argv):
print_help()
filename = argv[0] if len(argv) > 0 else "../../../../data/lena.jpg"
I = cv2.imread(filename, cv2.IMREAD_GRAYSCALE)
if I is None:
print('Error opening image')
return -1
## [expand]
rows, cols = I.shape
m = cv2.getOptimalDFTSize( rows )
n = cv2.getOptimalDFTSize( cols )
padded = cv2.copyMakeBorder(I, 0, m - rows, 0, n - cols, cv2.BORDER_CONSTANT, value=[0, 0, 0])
## [expand]
## [complex_and_real]
planes = [np.float32(padded), np.zeros(padded.shape, np.float32)]
complexI = cv2.merge(planes) # Add to the expanded another plane with zeros
## [complex_and_real]
## [dft]
cv2.dft(complexI, complexI) # this way the result may fit in the source matrix
## [dft]
# compute the magnitude and switch to logarithmic scale
# = > log(1 + sqrt(Re(DFT(I)) ^ 2 + Im(DFT(I)) ^ 2))
## [magnitude]
cv2.split(complexI, planes) # planes[0] = Re(DFT(I), planes[1] = Im(DFT(I))
cv2.magnitude(planes[0], planes[1], planes[0])# planes[0] = magnitude
magI = planes[0]
## [magnitude]
## [log]
matOfOnes = np.ones(magI.shape, dtype=magI.dtype)
cv2.add(matOfOnes, magI, magI) # switch to logarithmic scale
cv2.log(magI, magI)
## [log]
## [crop_rearrange]
magI_rows, magI_cols = magI.shape
# crop the spectrum, if it has an odd number of rows or columns
magI = magI[0:(magI_rows & -2), 0:(magI_cols & -2)]
cx = int(magI_rows/2)
cy = int(magI_cols/2)
q0 = magI[0:cx, 0:cy] # Top-Left - Create a ROI per quadrant
q1 = magI[cx:cx+cx, 0:cy] # Top-Right
q2 = magI[0:cx, cy:cy+cy] # Bottom-Left
q3 = magI[cx:cx+cx, cy:cy+cy] # Bottom-Right
tmp = np.copy(q0) # swap quadrants (Top-Left with Bottom-Right)
magI[0:cx, 0:cy] = q3
magI[cx:cx + cx, cy:cy + cy] = tmp
tmp = np.copy(q1) # swap quadrant (Top-Right with Bottom-Left)
magI[cx:cx + cx, 0:cy] = q2
magI[0:cx, cy:cy + cy] = tmp
## [crop_rearrange]
## [normalize]
cv2.normalize(magI, magI, 0, 1, cv2.NORM_MINMAX) # Transform the matrix with float values into a
## viewable image form(float between values 0 and 1).
## [normalize]
cv2.imshow("Input Image" , I ) # Show the result
cv2.imshow("spectrum magnitude", magI)
cv2.waitKey()
if __name__ == "__main__":
main(sys.argv[1:])
samples/python/tutorial_code/core/mat_mask_operations/mat_mask_operations.py
+13 -13
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@@ -1,9 +1,10 @@
from __future__ import print_function
import sys
import time
import numpy as np
import cv2
## [basic_method]
def is_grayscale(my_image):
return len(my_image.shape) < 3
@@ -26,7 +27,6 @@ def sharpen(my_image):
height, width, n_channels = my_image.shape
result = np.zeros(my_image.shape, my_image.dtype)
## [basic_method_loop]
for j in range(1, height - 1):
for i in range(1, width - 1):
@@ -36,17 +36,16 @@ def sharpen(my_image):
result[j, i] = saturated(sum_value)
else:
for k in range(0, n_channels):
sum_value = 5 * my_image[j, i, k] - my_image[j + 1, i, k] - my_image[j - 1, i, k] \
- my_image[j, i + 1, k] - my_image[j, i - 1, k]
sum_value = 5 * my_image[j, i, k] - my_image[j + 1, i, k] \
- my_image[j - 1, i, k] - my_image[j, i + 1, k]\
- my_image[j, i - 1, k]
result[j, i, k] = saturated(sum_value)
## [basic_method_loop]
return result
## [basic_method]
def main(argv):
filename = "../data/lena.jpg"
filename = "../../../../data/lena.jpg"
img_codec = cv2.IMREAD_COLOR
if argv:
@@ -57,8 +56,9 @@ def main(argv):
src = cv2.imread(filename, img_codec)
if src is None:
print "Can't open image [" + filename + "]"
print "Usage:\nmat_mask_operations.py [image_path -- default ../data/lena.jpg] [G -- grayscale]"
print("Can't open image [" + filename + "]")
print("Usage:")
print("mat_mask_operations.py [image_path -- default ../../../../data/lena.jpg] [G -- grayscale]")
return -1
cv2.namedWindow("Input", cv2.WINDOW_AUTOSIZE)
@@ -70,7 +70,7 @@ def main(argv):
dst0 = sharpen(src)
t = (time.time() - t) / 1000
print "Hand written function time passed in seconds: %s" % t
print("Hand written function time passed in seconds: %s" % t)
cv2.imshow("Output", dst0)
cv2.waitKey()
@@ -81,13 +81,13 @@ def main(argv):
[-1, 5, -1],
[0, -1, 0]], np.float32) # kernel should be floating point type
## [kern]
## [filter2D]
dst1 = cv2.filter2D(src, -1, kernel) # ddepth = -1, means destination image has depth same as input image
dst1 = cv2.filter2D(src, -1, kernel)
# ddepth = -1, means destination image has depth same as input image
## [filter2D]
t = (time.time() - t) / 1000
print "Built-in filter2D time passed in seconds: %s" % t
print("Built-in filter2D time passed in seconds: %s" % t)
cv2.imshow("Output", dst1)