While reading a normal image file it is showing this error.
I can use the imread command in command window directly but not in the M-file.
I had used the imread function like this:
BW=imread('C:\Users\parikh5555\Desktop\books\matlab image\1.jpg')
The error I'm getting is:
??? Error using ==> image
Error using ==> image
Numeric or logical matrix required for image CData
That error is most likely due to the fact that you are trying to use image as a variable when it is an actual function: http://www.mathworks.com/help/matlab/ref/image.html.
Specifically, you probably ran some code that used image as a variable, that variable is now cleared from the MATLAB workspace, and when you are trying to reuse that same M-file script after, it thus spits out that error because image is no longer being shadowed as a variable and now it is actually calling the function.
That error has nothing to do with imread. As such, you should go through your M file and make sure you have no variables called image and rename them to something else to prevent shadowing over the function unintentionally.
BTW, I'm going to close your question as it's due to a simple typographical error. Please take no offence.
Related
I'm trying to implement with the matlab function imhistmatch.
So I use following commends.
A= imread('example1.jpg')
B= imread('example2.jpg')
C= imhistmatch(A,B)
But there is problem like this.
?? Undefined functionor method 'imhistmatch' for input arguments of type 'uint8'
So What am I suppose to do for solve?
I am not sure about your question. Are you trying to implement imhistmatch?
Then probably your function is in the wrong folder or you have a typo in the functions name.
use
addpath('Pathto/imhistmatch')
to ensure that matlab can find your implemented function.
But maybe you want to use the function imhistmatch provided by the image processing toolbox. Then, I guess you don't have the image processing toolbox.
Try
ver
and check the output. You should find these lines:
MATLAB Version X.X (XXXXX)
Image Processing Toolbox Version X.X (XXXXX)
If not, then you may want to buy the image processing toolbox, get a evaluation version or maybe try octave.
On my computer the following works:
imhistmatch(ones(10),ones(10))
imhistmatch(ones(10,'uint8'),ones(10,'uint8'))
but when I type
imhistmatch(ones(10,'int8'),ones(10,'int8'))
I get an error:
Error using imhistmatch
Expected input number 1, A, to be one of these types:
uint8, uint16, double, int16, single
Instead its type was int8.
...
So, if it would be a type problem you would see another error.
Your error is the result of not having the proper function imhistmatch.
I have observed a strange behavior in running the same code in a Matlab function and in the command window. It's already described in How does scoping in Matlab work? , but I don't understand how I could solve my specific problem.
The code is the following:
exporteddata.m %File created by an external program
%to export data in Matlab format
surface = struct('vertices', [...]) ;
%I can't specify in the external program
%the name of the variable, it's always "surface"
My actual code is:
myfunction.m
function output = myfunction(input)
load(input);
n = size(surface.vertices);
....
When running
myfunction('exporteddata.m');
I get the following error:
??? No appropriate method, property, or field vertices for class hg.surface.
When running the same instructions from the command window or in debug mode, the code works well.
How can I specify in the function that I need the variable surface present in the workspace, not the Matlab function?
First of all, I must point out that surface is a built-in function in MATLAB, so overloading it is just... bad. Bad, bad, BAD!
Having said that, the MATLAB interpreter does a pretty good job at resolving variable names and usually tells them apart from function names correctly. So where's your problem, you ask?
I believe that you're using the wrong function: load is a function that loads data from MAT files into the workspace. It is not fit for m-files. By not executing "exportedata.m" properly, surface has never been created as a variable, so MATLAB identifies it as a function name. If you want to execute "exportedata.m", just type:
exportedata
and if you want to run the file with the filename stored in input, you can use run:
run(input)
By executing run(input) from within myfunction, surface should be created in myfunction's local scope, and it should work.
EDIT:
I've just tested it, and the interpreter still gets confused. so the issue of the variable name resolution remains. Here's a workaround:
function output = myfunction(input)
surface = 0; %// <-- Pay attention to this line
run(input);
n = size(surface.vertices);
Predefining surface allows the interpreter to identify it as a variable throughout your entire function. I've tried it and it works.
I tried to read an image and display it but i faced an error and i didn't understand it.can any one help me please, note that i use MATLAB R2010a, and the display below is the type of error.
>> imread('tas.jpg');
>> imshow('tas.jpg');
??? Attempt to call constructor image with incorrect letter case.
**Error in ==> basicImageDisplay at 9
hh = image(xdata,ydata,cdata, ...
Error in ==> imshow at 246
hh = basicImageDisplay(fig_handle,ax_handle,...**
I = imread('tas.jpg');
imshow(I);
The imread function reads the file and converts it to a RGB matrix of pixels. This is stored on the variable I. Then, you can call imshow passing this RGB matrix as a parameter ;)
edit you can call imshow with the filename as well, but it's not that useful because it does not return the matrix you will later use for processing. And as the error is thrown only on imshow, I'm guessing the imread function, for some reason, is working.
If not, just double check if the image is on the actual directory or in a directory on the path, or if it is not corrupted.
This might be the reason (from the below thread):
Reason: "current directory folder name is match with built-in function in matlab library and gives the error - Attempt to call constructor image with incorrect letter case".
Solution: change the folder name with unique name.
http://www.mathworks.com/matlabcentral/newsreader/view_thread/256922
So I am debugging some Matlab code and I get the dimension-doesn't-agree-error for some expressions. It's all nice that Matlab points to the correct line etc. However it would be nice if Matlab would output the dimensions of the variables involved in the error text so I don't have to deal with sizing them up myself. Sometimes for a long expression deep in a for loop it's a real hassle to figure out what exactly all dimensions are.
So is there a setting or hack for this?
The easiest way to deal with this issue is to type dbstop if error in the command window, and then to run the code. MATLAB will then stop execution right before it would throw the error, and it will open the editor on the line where the error would be thrown. Then you can inspect the array sizes at your leisure, and you can even, in the command window, try out possible fixes, because you will have access to all the variables currently active in the code.
You can try the try-catch-end block.
E.g.
try
%# Some error prone code
a = getA(b);
catch err_msg
%# Display any information you want
disp(size(b));
%# Display the error message
disp(err_msg.identifier);
disp(err_msg.message);
end
You can also throw in a breakpoint in the catch block if you want to evaluate things yourself.
HI
I wrote a program that use to work (swear to god) and has stopped from working. this code takes a series of BMPs and convert them into avi file. this is the code:
path4avi='C:/FadeOutMask/'; %dont forget the '/' in the end of the path
pathOfFrames='C:/FadeOutMask/';
NumberOfFiles=1;
NumberOfFrames=10;
%1:1:(NumberOfFiles)
for i=0:1:(NumberOfFiles-1)
FileName=strcat(path4avi,'FadeMaskAsael',int2str(i),'.avi') %the generated file
aviobj = avifile(FileName,'compression','None');
aviobj.fps=10;
for j=0:1:(NumberOfFrames-1)
Frame=strcat(pathOfFrames,'MaskFade',int2str(i*10+j),'.bmp') %not a good name for thedirectory
[Fa,map]=imread(Frame);
imshow(Fa,map);
F=getframe();
aviobj=addframe(aviobj,F)
end
aviobj=close(aviobj);
end
And this is the error I get:
??? Error using ==> checkDisplayRange at 22
HIGH must be greater than LOW.
Error in ==> imageDisplayValidateParams at 57
common_args.DisplayRange = checkDisplayRange(common_args.DisplayRange,mfilename);
Error in ==> imageDisplayParseInputs at 79
common_args = imageDisplayValidateParams(common_args);
Error in ==> imshow at 199
[common_args,specific_args] = ...
Error in ==> ConverterDosenWorkd at 19
imshow(Fa,map);
for some reason I cant put it as code segments. sorry
thank you
Ariel
Are the BMP images indexed? I think the map parameter only applies to images with indexed color maps.
The only way I am able to reproduce the error that you get is when map is a two-element vector where the first element is greater than the second. Note first that the function IMSHOW can be called with the following syntax:
imshow(I,[low high]);
In which I is a grayscale image and low and high specify the display range for the pixel intensities. The extra argument is ignored when I is an RGB image, but even then the value of high must be greater than the value of low or an error is thrown (the one you see above).
What's confusing is why map would be a two-element vector. When loading an image with IMREAD, the map output will either be empty (if the image is not an indexed image) or it will be an N-by-3 color map. I can't think of a situation where the built-in IMREAD would return a map argument with just 2 elements.
Based on the fact that you said it was working, and now suddenly isn't, I would suggest first checking to see if you have inadvertently created an m-file somewhere with the name imread. Doing so could cause that new imread function to be called instead of the built-in one, giving you different outputs than you expect.