MATLAB: Reference to non-existent field ‘image’. Error in Untitled2 (line 10) a80 = double(x1_image.image); —–Need help

doubleimread

A =imread('0001BG.tiff')
save('80s', 'A')
[x_file, x_folder] = uigetfile('*.mat', 'Select 80s-file');
x1_image = load([x_folder,x_file]);
cd(x_folder);
a80 = zeros(1024);
a80 = double(x1_image.image);

Best Answer

Aris - what make you think that image is a valid field for x1_image? In your example, you save the A variable to the 80s.mat file and so when you load this file as

x1_image = load([x_folder,x_file]);

then the field for x1_image will be A. Your code would then be

A =imread('0001BG.tiff')
save('80s', 'A')
[x_file, x_folder] = uigetfile('*.mat', 'Select 80s-file');
x1_image = load([x_folder,x_file]);
cd(x_folder);
a80 = zeros(1024);
a80 = double(x1_image.A);

The above code is only valid if A is the variable that is always saved to the 80s.mat files. You could use fieldnames to get the list of fields of x1_image and your code might become

A =imread('0001BG.tiff')
save('80s', 'A')
[x_file, x_folder] = uigetfile('*.mat', 'Select 80s-file');
x1_image = load([x_folder,x_file]);
structFieldnames = fieldnames(x1_image);
if ~isempty(structFieldnames)
    cd(x_folder);
    a80 = zeros(1024);
    a80 = double(getfield(x1_image, structFieldnames{1}));
end

Here I'm assuming that the first fieldname corresponds to the image of interest...

Related Solutions

MATLAB: Loading images from a .MAT file

The code shown only saves the names of the image files and not the image data itself. This is because the variable 'ListOfImageNames' is a cell array of names, and SAVE just stores it in the MAT-file as such.

If you want to save the actual image data, you should call IMREAD on each image to get its data into MATLAB, and then use SAVE for the actual data. One way to do this is to create a struct and add fields to this struct as you find and read images. Here's how that might look, based off of your code:

   function saveImages(folder)
   ListOfImageNames = {};
   ImagesToSave = struct();
   ImageFiles = dir([folder '/*.*']); % Get all files.
   for Index = 1:length(ImageFiles)
       baseFileName = ImageFiles(Index).name;
       [folder, name, extension] = fileparts(baseFileName);
       extension = upper(extension);
       % Let's save just those we are interested in:
       switch lower(extension)
           case {'.png', '.bmp', '.jpg', '.tif', '.avi'}
               % Allow only PNG, TIF, JPG, or BMP images
               ListOfImageNames = [ListOfImageNames baseFileName];
               ImagesToSave.(name) = imread(baseFileName);
           otherwise
       end
   end
   save('testimagebase.mat','-struct','ImagesToSave');

Now if you call LOAD on your MAT-file, you will be returned the same structure that you originally saved, with a field for each image containing its data:

   >> saveImages(pwd)
   >> myimages=load('testimagebase.mat')
   myimages = 
           image1: [2178x2448x3 uint8]
         myimage2: [676x1088x3 uint8]

MATLAB: I need load data .mat from file to the workspace. I used this code: filename = uigetfile({‘*.mat’}, ‘Select mat file’); but it´s non-functional. I need load data .mat to workspace and save to value with name x1. Is here somebody who know help? T

temp = load('z1.mat');
fn = fieldnames(temp);
x1 = temp.(fn{1});

This will load the "first" variable stored in the .mat file into the variable "x1".

Best Answer

Related Solutions

MATLAB: Loading images from a .MAT file

MATLAB: I need load data .mat from file to the workspace. I used this code: filename = uigetfile({‘*.mat’}, ‘Select mat file’); but it´s non-functional. I need load data .mat to workspace and save to value with name x1. Is here somebody who know help? T

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