import time
import cv2
import Calibration

# Calibration pattern size
pattern_size = ( 9, 6 )
# Get the camera
camera = cv2.VideoCapture( 1 )
# Acquisition loop
while( True ) :
    # Capture image-by-image
    _, image = camera.read()
    # Display the chessboard on the image
    chessboard = Calibration.PreviewChessboard( image, pattern_size )
    # Display the resulting image
    cv2.imshow( 'USB Camera', chessboard )
    # Keyboard interruption
    key = cv2.waitKey( 1 ) & 0xFF
    # Escape : quit the application
    if key == 27 : break
    # Space : save the image
    elif key == 32 :
        current_time = time.strftime( '%Y%m%d_%H%M%S' )
        print( 'Save image {} to disk...'.format( current_time ) )
        cv2.imwrite( 'image-{}.png'.format( current_time ), image )
# Release the camera
camera.release()
# Close OpenCV windows
cv2.destroyAllWindows()

import time
import cv2
import numpy as np
import Calibration

# Calibration pattern size
pattern_size = ( 9, 6 )
# Get the camera
camera = cv2.VideoCapture( 0 )
# Acquisition loop
while( True ) :
    # Capture image-by-image
    _, image = camera.read()
    # Copy the image for display
    chessboard = np.copy( image )
    # Display the chessboard on the image
    Calibration.PreviewChessboard( chessboard, pattern_size )
    # Display the resulting image
    cv2.imshow( 'USB Camera', chessboard )
    # Keyboard interruption
    key = cv2.waitKey( 1 ) & 0xFF
    # Escape : quit the application
    if key == 27 : break
    # Space : save the image
    elif key == 32 :
        current_time = time.strftime( '%Y%m%d_%H%M%S' )
        print( 'Save image {} to disk...'.format( current_time ) )
        cv2.imwrite( 'image-{}.png'.format( current_time ), image )
# Release the camera
camera.release()
# Close OpenCV windows
cv2.destroyAllWindows()

Change camera index, and fix the chessboard preview.
Change camera index, and fix the chessboard preview.

  import time
  import cv2
+ import numpy as np
  import Calibration
  
  # Calibration pattern size
  pattern_size = ( 9, 6 )
  # Get the camera
- camera = cv2.VideoCapture( 1 )
+ camera = cv2.VideoCapture( 0 )
  # Acquisition loop
  while( True ) :
      # Capture image-by-image
      _, image = camera.read()
+     # Copy the image for display
+     chessboard = np.copy( image )
      # Display the chessboard on the image
-     chessboard = Calibration.PreviewChessboard( image, pattern_size )
+     Calibration.PreviewChessboard( chessboard, pattern_size )
      # Display the resulting image
      cv2.imshow( 'USB Camera', chessboard )
      # Keyboard interruption
      key = cv2.waitKey( 1 ) & 0xFF
      # Escape : quit the application
      if key == 27 : break
      # Space : save the image
      elif key == 32 :
          current_time = time.strftime( '%Y%m%d_%H%M%S' )
          print( 'Save image {} to disk...'.format( current_time ) )
          cv2.imwrite( 'image-{}.png'.format( current_time ), image )
  # Release the camera
  camera.release()
  # Close OpenCV windows
  cv2.destroyAllWindows()
  
Change camera index, and fix the chessboard preview.
## Code Before:
import time
import cv2
import Calibration

# Calibration pattern size
pattern_size = ( 9, 6 )
# Get the camera
camera = cv2.VideoCapture( 1 )
# Acquisition loop
while( True ) :
    # Capture image-by-image
    _, image = camera.read()
    # Display the chessboard on the image
    chessboard = Calibration.PreviewChessboard( image, pattern_size )
    # Display the resulting image
    cv2.imshow( 'USB Camera', chessboard )
    # Keyboard interruption
    key = cv2.waitKey( 1 ) & 0xFF
    # Escape : quit the application
    if key == 27 : break
    # Space : save the image
    elif key == 32 :
        current_time = time.strftime( '%Y%m%d_%H%M%S' )
        print( 'Save image {} to disk...'.format( current_time ) )
        cv2.imwrite( 'image-{}.png'.format( current_time ), image )
# Release the camera
camera.release()
# Close OpenCV windows
cv2.destroyAllWindows()

## Instruction:
Change camera index, and fix the chessboard preview.
## Code After:
import time
import cv2
import numpy as np
import Calibration

# Calibration pattern size
pattern_size = ( 9, 6 )
# Get the camera
camera = cv2.VideoCapture( 0 )
# Acquisition loop
while( True ) :
    # Capture image-by-image
    _, image = camera.read()
    # Copy the image for display
    chessboard = np.copy( image )
    # Display the chessboard on the image
    Calibration.PreviewChessboard( chessboard, pattern_size )
    # Display the resulting image
    cv2.imshow( 'USB Camera', chessboard )
    # Keyboard interruption
    key = cv2.waitKey( 1 ) & 0xFF
    # Escape : quit the application
    if key == 27 : break
    # Space : save the image
    elif key == 32 :
        current_time = time.strftime( '%Y%m%d_%H%M%S' )
        print( 'Save image {} to disk...'.format( current_time ) )
        cv2.imwrite( 'image-{}.png'.format( current_time ), image )
# Release the camera
camera.release()
# Close OpenCV windows
cv2.destroyAllWindows()
