cv2 functions and data types (OpenCV python bindings)

Some OpenCV functions have restrictions on the input data type. When executing the cv2. Function () in python, an error may occur due to a mistake in specifying the ddepth of the input data type and output data depth. In the error message, values such as cv2.CV_8U are displayed as integers, so I'm confused as to what the input data type should be and how to specify the ddepth of the output data depth. I have something to do.

Similarly, building from the source code of the cv :: function () in C ++ may fail.

I will make a note so as not to repeat the same mistake.

dilate(...) dilate(src, kernel[, dst[, anchor[, iterations[, borderType[, borderValue]]]]]) -> dst

function	CV_8U	CV_8S	CV_16U	CV_16S	CV_32S	CV_32F	CV_64F
value	0	1	2	3	4	5	6
np.dtype	uint8	int8	uint16	int16	int32	float32	float64
cv2.dilate()	o	x	o	o	x	o	o
cv2.erode()	o	x	o	o	x	o	o
connectedComponentsWithStats() input	o	x	x	x	x	x	x
connectedComponentsWithStats() labels	x	x	o	x	o	x	x
connectedComponentsWithStats() stats	x	x	x	x	o	x	x
connectedComponentsWithStats() centroids	x	x	x	x	x	x	o

function	CV_8U	CV_8S	CV_16U	CV_16S	CV_32S	CV_32F	CV_64F
np.dtype	uint8	int8	uint16	int16	int32	float32	float64
cv2.Sobel() src	o	x	o	o	x	o	o
cv2.Sobel() dst	o	x	o	o	x	o	o
cv2.blur() src	o	x	o	o	o	o	o
GaussianBlur() src	o	x	o	o	x	o	o
filter2D() src	o	x	o	o	x	o	o
cartToPolar() src	x	x	x	x	x	o	o
polarToCart() src	x	x	x	x	x	o	o
magnitude() src	x	x	x	x	x	o	o
phase() src	x	x	x	x	x	o	o
cv2.sqrt() src	x	x	x	x	x	o	o
cvtColor()	o	x	o	x	x	o	x

I haven't fully checked the combination yet.

Sobel(...) Sobel(src, ddepth, dx, dy[, dst[, ksize[, scale[, delta[, borderType]]]]]) -> dst

Sobel combination Input image src type: vertical axis Determines the type of output image ddepth: Horizontal axis

	CV_8U	CV_8S	CV_16U	CV_16S	CV_32S	CV_32F	CV_64F
np.uint8	o	x	o	o	x	o	o
np.int8	x	x	x	x	x	x	x
np.uint16	o	x	o	o	x	o	o
np.int16	o	x	o	o	x	o	o
np.int32	x	x	x	x	x	x	x
np.float32	o	x	o	o	x	o	o
np.float64	o	x	o	o	x	x	o

Combination of cv2.filter2D (np.array (orgImg, dtype = npt), ddepth, kernel) Input image src type: vertical axis Determines the type of output image ddepth: Horizontal axis

	CV_8U	CV_8S	CV_16U	CV_16S	CV_32S	CV_32F	CV_64F
np.uint8	o	x	o	o	x	o	o
np.int8	x	x	x	x	x	x	x
np.uint16	x	x	o	x	x	o	o
np.int16	x	x	x	o	x	o	o
np.int32	x	x	x	x	x	x	x
np.float32	x	x	x	x	x	o	x
np.float64	x	x	x	x	x	x	o

function	CV_8U	CV_8S	CV_16U	CV_16S	CV_32S	CV_32F	CV_64F
np.dtype	uint8	int8	uint16	int16	int32	float32	float64
cv2.threshold() src	o	o	x	x	x	o	x
cv2.floodFill() src	o	o	x	x	x	o	x

function	CV_8U	CV_8S	CV_16U	CV_16S	CV_32S	CV_32F	CV_64F
np.dtype	uint8	int8	uint16	int16	int32	float32	float64
cv2.Canny() src	o	o	x	x	x	x	x
cv2.HoughLines()src Binary image	o	?	x	x	x	x	x
cv2.HoughCircles()src Binary image	o	?	x	x	x	x	x

# -*- coding: utf-8 -*-
u"""OpenCV cv::Check Mat type in Python
"""
import cv2
print cv2.CV_8U
print cv2.CV_8S
print cv2.CV_16U
print cv2.CV_16S
print cv2.CV_32S
print cv2.CV_32F
print cv2.CV_64F