MATLAB: Different values in matrix and in the plot of image

doubleimaging displaymatricesvector

Hello everybody,

I have a matrix A with double precision, 198*198 of size.Ploting the image using imshow(A,[]) and search using the Data cursor the value for the voxel (90,90) I get a value x, which is expected. However, using the command window to obtain the same value A(90,90) the value that I obtain is completely different of x. Can somebody explain why this happens and how can I get the value x in the command window?

Thank you in advance, Joaquim

Best Answer

You have to be careful with X,Y and rows, columns when indexing into a matrix. To get the value reported as X,Y you need to index your data as data(Y,X) although obviously for 90,90 this would make no difference.

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You're trying to extract the data from the image file?

imread will work find for this purpose. It will return an mxnx3 variable where each page represents the red, green, and blue values for each pixel respectively.

Or do you already have the data in MATLAB and you only want to take a small chunk of it? In that case, it would help to know the shape of the data. But I'll assume for the moment that you've got two vectors, LAT, and LON that represent the ranges of latitude and longitude and a 2D variable BATH. Let's assume LAT is a column vector, and LON is a row vector. BATH should be [length(LAT) length(LON)] in size.

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