(7) Raspberry Pi USB camera reading

https://blog.csdn.net/qq_42403190/article/details/90453305

Create a file

camera.py

 

Simple reading

# / usr / bin / the env to python3! 
# - * - Coding: UTF-. 8 - * - 
Import numpy AS NP 
Import CV2 

CAP = cv2.VideoCapture (0) # acquired from the camera video 

# acquires video player interface length and width 
width = int (cap.get (cv2.CAP_PROP_FRAME_WIDTH) + 0.5) 
height = int (cap.get (cv2.CAP_PROP_FRAME_HEIGHT) + 0.5) 

# define VideoWriter encoder creates an object 
fourcc = cv2.VideoWriter_fourcc (* 'mp4v' ) # Be sure to Lower Case The use 
OUT = cv2.VideoWriter ( 'output.mp4', the fourcc, 20.0, (width, height)) 

the while (cap.isOpened ()): 
    # camera reads the frame 
    RET, frame = cap.read () 
    IF == True RET: 
        # output current frame 
        out.write (frame) 

        cv2.imshow ( 'My Camera', frame) 
 
        # Q keyboard press exit
        IF (cv2.waitKey (. 1) & 0xFF) == the ord ( 'Q'):
            BREAK 
    the else: 
        BREAK 

# release resources 
out.release () 
cap.release () 
cv2.destroyAllWindows ()

　　

Process integration

 

! # / usr / bin / the env to python3 
# - * - Coding: UTF-. 8 - * - 
Import CV2 
Import numpy AS NP 
name = 0 
CAP = cv2.VideoCapture (0) 
 
cap.set (3,640) 
cap.set (4,480) 
 
RET, Frame = cap.read () 
rows, cols, channels = frame.shape 
Print (cols, rows, channels) 
 
# image preprocessing 
DEF IMG P (IMG): 
 
    # grayscale 
    gray_img = cv2.cvtColor (frame, cv2. COLOR_BGR2GRAY) 
 
    # smoothing 
    Blur = cv2.blur (gray_img, (3,3)) 
 
    # binarization 
    RET1, ThI = cv2.threshold (Blur, 190, 255, cv2.THRESH_BINARY) 
 
    # perspective transformation 
    B = 50  
    PTS1 = NP .float32 ([[b, 0] , [cols-b, 0], [0, rows], [cols, rows]])
    PTS2 = NP .float32 ([[0, 0] , [cols, 0], [0, rows], [cols, rows]])
    M = cv2.getPerspectiveTransform(pts1, pts2)
    dst = cv2.warpPerspective(blur, M, (cols, rows))
 
    return dst
 
 
while(1):
        ret,frame = cap.read()
        dst = img_p(frame)
        cv2.imshow('usb camera', dst)
 
        k = cv2.waitKey(50)
        if (k == ord('q')):
            break
        elif(k == ord('s')):
                #name = input('name:')
                name += 1
                filename = r'./camera/' + str(name) + '.jpg'
                cv2.imwrite(filename, dst)
                print(filename)
                #break 
cap.release()
cv2.destroyAllWindows()

　　

Run the file

python3 camera.py

　　

result: