Basic Structures

CvPoint

class CvPoint

2D point with integer coordinates (usually zero-based).

2D point, represented as a tuple (x, y) , where x and y are integers.

CvPoint2D32f

class CvPoint2D32f

2D point with floating-point coordinates

2D point, represented as a tuple (x, y) , where x and y are floats.

CvPoint3D32f

class CvPoint3D32f

3D point with floating-point coordinates

3D point, represented as a tuple (x, y, z) , where x, y and z are floats.

CvPoint2D64f

class CvPoint2D64f

2D point with double precision floating-point coordinates

2D point, represented as a tuple (x, y) , where x and y are floats.

CvPoint3D64f

class CvPoint3D64f

3D point with double precision floating-point coordinates

3D point, represented as a tuple (x, y, z) , where x, y and z are floats.

CvSize

class CvSize

Pixel-accurate size of a rectangle.

Size of a rectangle, represented as a tuple (width, height) , where width and height are integers.

CvSize2D32f

class CvSize2D32f

Sub-pixel accurate size of a rectangle.

Size of a rectangle, represented as a tuple (width, height) , where width and height are floats.

CvRect

class CvRect

Offset (usually the top-left corner) and size of a rectangle.

Rectangle, represented as a tuple (x, y, width, height) , where all are integers.

CvScalar

class CvScalar

A container for 1-,2-,3- or 4-tuples of doubles.

CvScalar is always represented as a 4-tuple.

>>> import cv
>>> cv.Scalar(1, 2, 3, 4)
(1.0, 2.0, 3.0, 4.0)
>>> cv.ScalarAll(7)
(7.0, 7.0, 7.0, 7.0)
>>> cv.RealScalar(7)
(7.0, 0.0, 0.0, 0.0)
>>> cv.RGB(17, 110, 255)
(255.0, 110.0, 17.0, 0.0)

CvTermCriteria

class CvTermCriteria

Termination criteria for iterative algorithms.

Represented by a tuple (type, max_iter, epsilon) .

type

CV_TERMCRIT_ITER , CV_TERMCRIT_EPS or CV_TERMCRIT_ITER | CV_TERMCRIT_EPS

max_iter

Maximum number of iterations

epsilon

Required accuracy

(cv.CV_TERMCRIT_ITER, 10, 0)                         # terminate after 10 iterations
(cv.CV_TERMCRIT_EPS, 0, 0.01)                        # terminate when epsilon reaches 0.01
(cv.CV_TERMCRIT_ITER | cv.CV_TERMCRIT_EPS, 10, 0.01) # terminate as soon as either condition is met

CvMat

class CvMat

A multi-channel 2D matrix. Created by CreateMat , LoadImageM , CreateMatHeader , fromarray .

type

A CvMat signature containing the type of elements and flags, int

step

Full row length in bytes, int

rows

Number of rows, int

cols

Number of columns, int

tostring() → str

Returns the contents of the CvMat as a single string.

CvMatND

class CvMatND

Multi-dimensional dense multi-channel array.

type

A CvMatND signature combining the type of elements and flags, int

tostring() → str

Returns the contents of the CvMatND as a single string.

IplImage

class IplImage

The IplImage object was inherited from the Intel Image Processing Library, in which the format is native. OpenCV only supports a subset of possible IplImage formats.

nChannels

Number of channels, int.

width

Image width in pixels

height

Image height in pixels

depth

Pixel depth in bits. The supported depths are:

IPL_DEPTH_8U

Unsigned 8-bit integer

IPL_DEPTH_8S

Signed 8-bit integer

IPL_DEPTH_16U

Unsigned 16-bit integer

IPL_DEPTH_16S

Signed 16-bit integer

IPL_DEPTH_32S

Signed 32-bit integer

IPL_DEPTH_32F

Single-precision floating point

IPL_DEPTH_64F

Double-precision floating point

origin

0 - top-left origin, 1 - bottom-left origin (Windows bitmap style)

tostring() → str

Returns the contents of the CvMatND as a single string.

CvArr

class CvArr

Arbitrary array

CvArr is used only as a function parameter to specify that the parameter can be:

• an IplImage
• a CvMat
• any other type that exports the array interface