Issue with imresize, resizeParseInputs

https://www.mathworks.com/matlabcentral/answers/2065691-brace-indexing-into-the-result-of-a-function-call-is-not-supported

Error using resizeParseInputs
Expected input number 2, [MROWS NCOLS], to be positive.

Error in matlab.images.internal.resize.resizeParseInputs>scaleOrSize (line 215)
    validateattributes(arg, {'numeric'}, {'vector', 'real', 'positive'}, ...

Error in matlab.images.internal.resize.resizeParseInputs>parsePreMethodArgs (line 163)
[scale, output_size] = scaleOrSize(next, next_arg);

Error in matlab.images.internal.resize.resizeParseInputs (line 28)
    parsePreMethodArgs(varargin, method_arg_idx, first_param_string_idx);

Error in imresize (line 153)
params = matlab.images.internal.resize.resizeParseInputs(args{:});

Error in focusStack>recontructFromPyramid (line 59)
        expanded = imresize(resultImage, size(pyramid{level}), 'bilinear');

Error in focusStack (line 21)
    resultImage = recontructFromPyramid(blendedPyramid);
    
    

Hello, I had another issue with the code from the link. I understand that the issue may stem form the argument for the for loop being negative when the input for resize needs to be positive. Is there a way to make this work?

[Image Analyst]

What is

size(pyramid{level})

?

[Bryce]

%focus stacking function using Laplacian pyramid 

function resultImage = focusStack(imageStack)
    numImages = numel(imageStack);

    %Convert images to double for processing 
    for i = 1:numImages
        imageStack{i} = im2double(imageStack{i});
    end

    %Initialize Laplacian pyrimid for each image
    laplacianPyramids = cell(1, numImages);
    for i = 1:numImages
        laplacianPyramids{i} = laplacianPyramid(imageStack{i});
    end

    %combine Laplacian pyramid to create the final result 
    blendedPyramid = blendLaplacianPyramids(laplacianPyramids);

    %Reconstruct the final focus-stacked Image
    resultImage = recontructFromPyramid(blendedPyramid);
end

% Laplacian pyramid generation for an image

function pyramid = laplacianPyramid(image)
    levels = 12; %Number of pyramid levels (adjust as needed)
      pyramid = cell(1, levels);
      pyramid{1} = image;
    
      for i = 2:levels 
        smoothed = imgaussfilt(pyramid{i-1}, 2); %Apply Gausian smoothing 
        difference = pyramid{i-1} -smoothed; %Compute difference 
        pyramid{i} = difference;
      end
    end

    %blend the laplacian pyramid to create the final result 
function blendedPyramid = blendLaplacianPyramids(pyramid)
    numLevels = numel(pyramid{1});
    blendedPyramid = cell(1, numLevels);
    
    for level = 1:numLevels
        blendedLevel = zeros(size(pyramid{1}{level}));
    
        for level = 1:numel(pyramid)
            blendedLevel = blendedLevel + pyramid{1}{level};
        end
    
        blendedPyramid{level} = blendedLevel;
    end
    end
%Reconstruct image from blended Laplacian 
function resultImage = recontructFromPyramid(pyramid)
    numLevels = numel(pyramid);
    resultImage = pyramid{numLevels};

    for level = numLevels-1:-1:1
        expanded = imresize(resultImage, size(pyramid{level}), 'bilinear');
        resultImage = expanded + pyramid{level};
    end 
end 

Here is the code

Answer 1

[DGM]

See the comments. It ran without errors, but I don't know if the output is right or if I'm using it correctly.

%blend the laplacian pyramid to create the final result 
function blendedPyramid = blendLaplacianPyramids(pyramid)
    numLevels = numel(pyramid{1});
    blendedPyramid = cell(1, numLevels);
    for level = 1:numLevels % this loop variable is already called 'level'
        blendedLevel = zeros(size(pyramid{1}{level}));
    
        for plevel = 1:numel(pyramid) % so name this something different
            blendedLevel = blendedLevel + pyramid{1}{plevel};
        end
    
        blendedPyramid{level} = blendedLevel;
    end
end
	
%Reconstruct image from blended Laplacian 
function resultImage = recontructFromPyramid(pyramid)
    numLevels = numel(pyramid);
    resultImage = pyramid{numLevels};
    for level = numLevels-1:-1:1
        % geometry passed to imresize() can't be longer than 2
        expanded = imresize(resultImage, size(pyramid{level},1:2), 'bilinear');
        resultImage = expanded + pyramid{level};
    end 
end 

[Bryce]

Thanks I got a result with this. I just need to edit the image for the results I wanted results

Answer 2

[Cris LaPierre]

At least one of your resize dimensions is 0. It appears, then, that your code is producing a result you did not anticipate. Check your code and if necesesary add a check so that your resize dimensions can never be 0.

img = imread("peppers.png");
% This works
img1 = imresize(img,[5,5],"bilinear");
% This reproduces your error
img2 = imresize(img,[0,5],"bilinear");

Error using resizeParseInputs
Expected input number 2, [MROWS NCOLS], to be positive.

Error in matlab.images.internal.resize.resizeParseInputs>scaleOrSize (line 215)
validateattributes(arg, {'numeric'}, {'vector', 'real', 'positive'}, ...

Error in matlab.images.internal.resize.resizeParseInputs>parsePreMethodArgs (line 163)
[scale, output_size] = scaleOrSize(next, next_arg);

Error in matlab.images.internal.resize.resizeParseInputs (line 28)
parsePreMethodArgs(varargin, method_arg_idx, first_param_string_idx);

Error in imresize (line 153)
params = matlab.images.internal.resize.resizeParseInputs(args{:});