Module ReMake.Raspberry_Pi.calibration

Classes

class calibration (r=0)

This class implements the calibration algorithm for the Raspberry Pi Camera and can be used to generate the distortion coefficients matrix for a specific resolution.

The calibartion object used to generate the distortion matrix.

Args

r : int, optional

resolution used to compute the matrix. Defaults to 0.

Expand source code

class calibration:
    """This class implements the calibration algorithm for the Raspberry Pi Camera and can be used to generate the distortion coefficients matrix for a specific resolution.
    """

    def __init__(self, r=0) -> None:
        """The calibartion object used to generate the distortion matrix.

        Args:
            r (int, optional): resolution used to compute the matrix. Defaults to 0.
        """

        self.res = [(1280, 720), (4056, 3040)]
        self.r=r

    def setRes(self, i):
        """Set the resolution of the scan.

        Args:
            i (int): the resolution of the scan
        """

        self.r = i

    def setResxy(self, x, y):
        """Set the resolution of the scan by vertical and horizontal components but only if it is supported.

        Args:
            x (int): horizontal resolution
            y (int): vertical resolution
        """

        try:
            index = self.res.index((x,y))
            self.r = index 
        except:
            print("THE RESOLUTION ISN'T SUPPORTED")
    
    def save_coefficients(self, mtx, dist, path):
        """Save the camera matrix and the distortion coefficients to given path/file.

        Args:
            mtx (nparray): distortion matrix coefficients K
            dist (nparray): distortion matrix coefficients D
            path (str): location where the matrix should be saved
        """

        cv_file = cv2.FileStorage(path, cv2.FILE_STORAGE_WRITE)
        cv_file.write("K", mtx)
        cv_file.write("D", dist)
        # note you *release* you don't close() a FileStorage object
        cv_file.release()
    
    def getRes(self):
        """Get the resolution of the scan.

        Returns:
            list: resolution of the scan
        """

        return self.res[self.r]
    
    def getimg(self, n):
        """Take a series of picture using the Raspberry Pi Camera and save them locally.

        Args:
            n (int): number of picture to take
        """

        with picamera.PiCamera() as camera:
            camera.resolution = self.getRes()
            camera.framerate = 1
            # Wait for the automatic gain control to settle
            time.sleep(2)
            # Now fix the values
            #camera.shutter_speed = camera.exposure_speed
            #camera.exposure_mode = 'off'
            #g = camera.awb_gains
            #camera.awb_mode = 'off'
            #camera.awb_gains = g
            # Finally, take several photos with the fixed settings
            camera.capture_sequence(['cal/img%02d.jpg' % i for i in range(n)])
        
    def genMatrix(self):
        """Generate the distortion matrix.
        """

        self.getimg(10)
        # termination criteria
        criteria = (cv2.TERM_CRITERIA_EPS + cv2.TERM_CRITERIA_MAX_ITER, 30, 0.001)

        # prepare object points, like (0,0,0), (1,0,0), (2,0,0) ....,(6,5,0)
        objp = np.zeros((9*6,3), np.float32)
        objp[:,:2] = np.mgrid[0:9,0:6].T.reshape(-1,2)

        # Arrays to store object points and image points from all the images.
        objpoints = [] # 3d point in real world space
        imgpoints = [] # 2d points in image plane.

        images = glob.glob('cal/*.jpg')
        print(len(images))

        for fname in images:
            
            img = cv2.imread(fname)
            if not (img is None):


                gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
                #cv2.imshow('img',gray)
                #cv2.waitKey(500)
                # Find the chess board corners
                ret, corners = cv2.findChessboardCorners(gray, (9,6),None)

                # If found, add object points, image points (after refining them)
                if ret == True:
                    objpoints.append(objp)

                    corners2 = cv2.cornerSubPix(gray,corners,(11,11),(-1,-1),criteria)
                    imgpoints.append(corners2)

                    # Draw and display the corners
                    #cv2.drawChessboardCorners(img, (9,6), corners2,ret)
                    #cv2.imshow('img',img)
                    #cv2.imwrite('test.jpg',img)
                    #cv2.waitKey(500)

        #print(objpoints)
        #print('--------------------')
        #print(imgpoints)

        ret, mtx, dist, rvecs, tvecs = cv2.calibrateCamera(objpoints, imgpoints, gray.shape[::-1],None,None)
        #print('ret={}, mtx={}, dist={}, rvecs={}, tvecs={}'.format(ret, mtx, dist, rvecs, tvecs))

        #img = cv2.imread('im0.jpg')
        #h,  w = img.shape[:2]
        #newcameramtx, roi=cv2.getOptimalNewCameraMatrix(mtx,dist,(w,h),1,(w,h))
        # undistort
        #dst = cv2.undistort(img, mtx, dist, None, newcameramtx)

        # crop the image
        #x,y,w,h = roi
        #dst = dst[y:y+h, x:x+w]
        #cv2.imwrite('calibresult.png',dst)

        self.save_coefficients(mtx, dist, '/home/pi/TestCamera/coef{}.yml'.format(self.r))

    def getMatrix(self):
        """Get the name of the file containing the distortion matrix.

        Returns:
            str: name of the distortion matrix or -1 if it doesn't exists.
        """
        
        matrix = 'coef{}.yml'.format(self.r)
        if exists(matrix):
            return matrix
        return -1

Methods

def genMatrix(self)

Generate the distortion matrix.

Expand source code

def genMatrix(self):
    """Generate the distortion matrix.
    """

    self.getimg(10)
    # termination criteria
    criteria = (cv2.TERM_CRITERIA_EPS + cv2.TERM_CRITERIA_MAX_ITER, 30, 0.001)

    # prepare object points, like (0,0,0), (1,0,0), (2,0,0) ....,(6,5,0)
    objp = np.zeros((9*6,3), np.float32)
    objp[:,:2] = np.mgrid[0:9,0:6].T.reshape(-1,2)

    # Arrays to store object points and image points from all the images.
    objpoints = [] # 3d point in real world space
    imgpoints = [] # 2d points in image plane.

    images = glob.glob('cal/*.jpg')
    print(len(images))

    for fname in images:
        
        img = cv2.imread(fname)
        if not (img is None):


            gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
            #cv2.imshow('img',gray)
            #cv2.waitKey(500)
            # Find the chess board corners
            ret, corners = cv2.findChessboardCorners(gray, (9,6),None)

            # If found, add object points, image points (after refining them)
            if ret == True:
                objpoints.append(objp)

                corners2 = cv2.cornerSubPix(gray,corners,(11,11),(-1,-1),criteria)
                imgpoints.append(corners2)

                # Draw and display the corners
                #cv2.drawChessboardCorners(img, (9,6), corners2,ret)
                #cv2.imshow('img',img)
                #cv2.imwrite('test.jpg',img)
                #cv2.waitKey(500)

    #print(objpoints)
    #print('--------------------')
    #print(imgpoints)

    ret, mtx, dist, rvecs, tvecs = cv2.calibrateCamera(objpoints, imgpoints, gray.shape[::-1],None,None)
    #print('ret={}, mtx={}, dist={}, rvecs={}, tvecs={}'.format(ret, mtx, dist, rvecs, tvecs))

    #img = cv2.imread('im0.jpg')
    #h,  w = img.shape[:2]
    #newcameramtx, roi=cv2.getOptimalNewCameraMatrix(mtx,dist,(w,h),1,(w,h))
    # undistort
    #dst = cv2.undistort(img, mtx, dist, None, newcameramtx)

    # crop the image
    #x,y,w,h = roi
    #dst = dst[y:y+h, x:x+w]
    #cv2.imwrite('calibresult.png',dst)

    self.save_coefficients(mtx, dist, '/home/pi/TestCamera/coef{}.yml'.format(self.r))

def getMatrix(self)

Get the name of the file containing the distortion matrix.

Returns

str

name of the distortion matrix or -1 if it doesn't exists.

Expand source code

def getMatrix(self):
    """Get the name of the file containing the distortion matrix.

    Returns:
        str: name of the distortion matrix or -1 if it doesn't exists.
    """
    
    matrix = 'coef{}.yml'.format(self.r)
    if exists(matrix):
        return matrix
    return -1

def getRes(self)

Get the resolution of the scan.

Returns

list

resolution of the scan

Expand source code

def getRes(self):
    """Get the resolution of the scan.

    Returns:
        list: resolution of the scan
    """

    return self.res[self.r]

def getimg(self, n)

Take a series of picture using the Raspberry Pi Camera and save them locally.

Args

n : int

number of picture to take

Expand source code

def getimg(self, n):
    """Take a series of picture using the Raspberry Pi Camera and save them locally.

    Args:
        n (int): number of picture to take
    """

    with picamera.PiCamera() as camera:
        camera.resolution = self.getRes()
        camera.framerate = 1
        # Wait for the automatic gain control to settle
        time.sleep(2)
        # Now fix the values
        #camera.shutter_speed = camera.exposure_speed
        #camera.exposure_mode = 'off'
        #g = camera.awb_gains
        #camera.awb_mode = 'off'
        #camera.awb_gains = g
        # Finally, take several photos with the fixed settings
        camera.capture_sequence(['cal/img%02d.jpg' % i for i in range(n)])

def save_coefficients(self, mtx, dist, path)

Save the camera matrix and the distortion coefficients to given path/file.

Args

mtx : nparray

distortion matrix coefficients K

dist : nparray

distortion matrix coefficients D

path : str

location where the matrix should be saved

Expand source code

def save_coefficients(self, mtx, dist, path):
    """Save the camera matrix and the distortion coefficients to given path/file.

    Args:
        mtx (nparray): distortion matrix coefficients K
        dist (nparray): distortion matrix coefficients D
        path (str): location where the matrix should be saved
    """

    cv_file = cv2.FileStorage(path, cv2.FILE_STORAGE_WRITE)
    cv_file.write("K", mtx)
    cv_file.write("D", dist)
    # note you *release* you don't close() a FileStorage object
    cv_file.release()

def setRes(self, i)

Set the resolution of the scan.

Args

i : int

the resolution of the scan

Expand source code

def setRes(self, i):
    """Set the resolution of the scan.

    Args:
        i (int): the resolution of the scan
    """

    self.r = i

def setResxy(self, x, y)

Set the resolution of the scan by vertical and horizontal components but only if it is supported.

Args

x : int

horizontal resolution

y : int

vertical resolution

Expand source code

def setResxy(self, x, y):
    """Set the resolution of the scan by vertical and horizontal components but only if it is supported.

    Args:
        x (int): horizontal resolution
        y (int): vertical resolution
    """

    try:
        index = self.res.index((x,y))
        self.r = index 
    except:
        print("THE RESOLUTION ISN'T SUPPORTED")