getBasePtr

Create MATLAB interface object for OpenCV base class

Syntax

output = getBasePtr(ptr)

Description

output = getBasePtr(ptr) creates a MATLAB^® interface object for an OpenCV base class pointed by a smart pointer ptr. You can use the interface object to access the public member functions and public attributes of an OpenCV base class directly from MATLAB.

Examples

Perform Histogram Equalization by Using OpenCV in MATLAB

Perform histogram equalization of an image by using the prebuilt MATLAB interface to the OpenCV function cv::CLAHE. The cv::CLAHE function is a base class, and you must create a MATLAB interface object by using the getBasePtr utility function to access the public methods and attributes of the base class.

Add the MATLAB interface to OpenCV package names to the import list.

import clib.opencv.*;
import vision.opencv.util.*;

Read an image into the MATLAB workspace.

img = imread("cameraman.tif");

Create the MATLAB interface objects for the OpenCV MatND and InputArray classes to store the input image.

[inputMat,inputArray] = createMat(img);

Create the MATLAB interface objects for the OpenCV MatND and OutputArray classes to write the output image returned by the OpenCV function.

[outputMat,outputArray] = createMat;

Create a MATLAB interface object to represent the smart pointer of the OpenCV CLAHE class cv::CLAHE.

ocvPtr = cv.createCLAHE;

Create a MATLAB interface object for the base class cv::CLAHE.

basePtr = getBasePtr(ocvPtr);

Set the value of clip limit to 4.

basePtr.setClipLimit(4);

Perform contrast-limited adaptive histogram equalization by using the apply method of the cv::CLAHE base class.

basePtr.apply(inputArray,outputArray);

Read the enhanced output image.

enhanced = getImage(outputArray);

Display the original input and the enhanced output image.

figure
imshow(img)
title("Input Image")

figure
imshow(enhanced)
title("Enhanced Image")

Input Arguments

ptr — OpenCV smart pointer

Ptr_cv_<_T> interface object

OpenCV smart pointer, specified as a Ptr_cv_<_T> interface object. This MATLAB interface object is a representation of an OpenCV smart pointer cv::Ptr<_T>.

Output Arguments

output — Representation of OpenCV base class

MATLAB interface object

Representation of OpenCV base class, returned as a MATLAB interface object. You can use the object to directly access the public member functions and public attributes of an OpenCV base class.