You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: OpticalFlowPCAFlow.m
    path of file: ./repos/mexopencv/opencv_contrib/+cv
    
    the code of the file until where you have to start completion: classdef OpticalFlowPCAFlow < handle
    %OPTICALFLOWPCAFLOW  PCAFlow algorithm
    %
    % Implementation of the PCAFlow algorithm from the following paper:
    % [Wulffcvpr2015].
    %
    % There are some key differences which distinguish this algorithm from the
    % original PCAFlow (see paper):
    %
    % - Discrete Cosine Transform basis is used instead of basis extracted
    %   with PCA. Reasoning: DCT basis has comparable performance and it
    %   doesn't require additional storage space. Also, this decision helps to
    %   avoid overloading the algorithm with a lot of external input.
    % - Usage of built-in OpenCV feature tracking 
    
function delete(this)
            %DELETE  Destructor
            %
            %     obj.delete()
            %
            % See also: cv.OpticalFlowPCAFlow
            %
            if isempty(this.id), return; end
            OpticalFlowPCAFlow_(this.id, 'delete');
        end
    end

    %% DenseOpticalFlow
    methods
        function flow = calc(this, I0, I1, varargin)
            %CALC  Calculates an optical flow
            %
            %     flow = obj.calc(I0, I1)
            %     flow = obj.calc(I0, I1, 'OptionName',optionValue, ...)
            %
            % ## Input
            % * __I0__ first 8-bit single-channel input image.
            % * __I1__ second input image of the same size and the same type
            %   as `I0`.
            %
            % ## Output
            % * __flow__ computed flow image that has the same size as `I0`
            %   and type `single` (2-channels).
            %
            % ## Options
            % * __InitialFlow__ specify the initial flow. Not set by default.
            %
            % See also: cv.OpticalFlowPCAFlow
            %
            flow = OpticalFlowPCAFlow_(this.id, 'calc', I0, I1, varargin{:});
        end