我正在尝试使用python中的opencv cv2校准我的单个网络摄像头。我正在使用cv2.findChessboardCorners和cv2.calibrateCamera函数。但是，我从calibrateCamera函数返回的均方根看起来非常高。无论使用多少个框架，它总是大约50个。我读到好的值范围从0到1。我在一张贴在木板上的纸上使用5x8黑白格子图案。能有人帮助我降低这个水平吗？奇怪的是我使用了我从Blender渲染的图像，这是一个3D建模软件，其中没有镜头失真，并且板的坐标是确定的，我能够得到0.22的RMS，这是好的。使用类似的代码虽然我不能用我的网络摄像头复制这些结果。也许我错过了一些东西。非常感谢所有看过这个的人。这是完整的代码：
import sys
import os
import numpy as np
import cv2
import time
'''
This module finds the intrinsic parameters of the camera. These parameters include
the focal length, pixel aspect ratio, image center, and lens distortion (see wiki
entry for "camera resectioning" for more detail). It is important to note that the
parameters found by this class are independent of location and rotation of the camera.
Thus, it only needs to be calculated once assuming the lens and focus of the camera is
unaltered. The location and rotation matrix are defined by the extrinsic parameters.
'''
class Find_Intrinsics:
'''Finds the intrinsic parameters of the camera.'''
def __init__(self):
#Import user input from Blender in the form of argv's
self.rows = int(sys.argv[1])
self.cols = int(sys.argv[2])
self.board_width_pxls = float(sys.argv[3])
self.pxls_per_sq_unit = float(sys.argv[4])
self.printer_scale = float(sys.argv[5])
def find_calib_grid_points(self,cols,rows,board_width_pxls,pxls_per_sq_unit,printer_scale):
'''Defines the distance of the board squares from each other and scale them.
The scaling is to correct for the scaling of the printer. Most printers
cannot print all the way to the end of the page and thus scale images to
fit the entire image. If the user does not desire to maintain real world
scaling, then an arbitrary distance is set. The 3rd value appended to
calib_points signifies the depth of the points and is always zero because
they are planar.
'''
#should be dist for each square
point_dist = (((board_width_pxls)/(pxls_per_sq_unit))*printer_scale)/(cols+2)
calib_points = []
for i in range(0,cols):
for j in range(0,rows):
pointX = 0 + (point_dist*j)
pointY = 0 - (point_dist*i)
calib_points.append((pointX,pointY,0))
np_calib_points = np.array(calib_points,np.float32)
return np_calib_points
def main(self):
print '---------------------------Finding Intrinsics----------------------------------'
np_calib_points = self.find_calib_grid_points(self.cols,self.rows,self.board_width_pxls,
self.pxls_per_sq_unit,self.printer_scale)
pattern_size = (self.cols,self.rows)
obj_points = []
img_points = []
camera = cv2.VideoCapture(0)
found_count = 0
while True:
found_cam,img = camera.read()
h, w = img.shape[:2]
print h,w
gray_img = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)
found, corners = cv2.findChessboardCorners(img, pattern_size)
if found:
term = ( cv2.TERM_CRITERIA_EPS + cv2.TERM_CRITERIA_COUNT, 30, 0.1 )
cv2.cornerSubPix(gray_img, corners, (5, 5), (-1, -1), term)
cv2.drawChessboardCorners(img, pattern_size, corners, found)
found_count+=1
img_points.append(corners.reshape(-1, 2))
obj_points.append(np_calib_points)
cv2.putText(img,'Boards found: '+str(found_count),(30,30),
cv2.FONT_HERSHEY_DUPLEX, 0.8,(0,0,255,1))
cv2.putText(img,'Press any key when finished',(30,h-30),
cv2.FONT_HERSHEY_DUPLEX, 0.8,(0,0,255,1))
cv2.imshow("webcam",img)
if (cv2.waitKey (1000) != -1):
cv2.destroyAllWindows()
del(camera)
np_obj_points = np.array(obj_points)
print "Calibrating.Please be patient"
start = time.clock()
#OpenCV function to solve for camera matrix
try:
print obj_points[0:10]
rms, camera_matrix, dist_coefs, rvecs, tvecs = cv2.calibrateCamera(obj_points, img_points, (w, h))
print "RMS:", rms
print "camera matrix:\n", camera_matrix
print "distortion coefficients: ", dist_coefs
#Save the camera matrix and the distortion coefficients to the hard drive to use
#to find the extrinsics
#want to use same file directory as this file
#directory = os.path.dirname(os.path.realpath('Find_Intrinsics.py'))
np.save('C:\\Users\\Owner\\Desktop\\3D_Scanning\\Blender_3d_Scanning\\camera_matrix.npy',camera_matrix)
np.save('C:\\Users\\Owner\\Desktop\\3D_Scanning\\Blender_3d_Scanning\\dist_coefs.npy',dist_coefs)
elapsed = (time.clock() - start)
print("Elapsed time: ", elapsed, " seconds")
img_undistort = cv2.undistort(img,camera_matrix,dist_coefs)
cv2.namedWindow('Undistorted Image',cv2.WINDOW_NORMAL)#WINDOW_NORMAL used bc WINDOW_AUTOSIZE does not let you resize
cv2.resizeWindow('Undistorted Image',w,h)
cv2.imshow('Undistorted Image',img_undistort)
cv2.waitKey(0)
cv2.destroyAllWindows()
break
except:
print "\nSorry, an error has occurred. Make sure more than zero boards are found."
break
if __name__ == '__main__' and len(sys.argv)== 6:
Intrinsics = Find_Intrinsics()
Intrinsics_main = Intrinsics.main()
else:
print "Incorrect number of args found. Make sure that the python27 filepath is entered correctly."
print '--------------------------------------------------------------------------------'
答案 0 :(得分：1)
for j in range(0,rows):
for i in range(0,cols):
pointX = 0 + (point_dist*i)
pointY = 0 - (point_dist*j)
calib_points.append((pointX,pointY,0))
np_calib_points = np.array(calib_points,np.float32)
感谢所有看过这个并给我发送心灵信息的人，所以我可以把这个看成是正确的哈哈。他们工作了！我的RMS是0.33！