MATLAB: Reshape array for 256 by 256 matrix showing 16 by 256

Image Processing Toolboxreshape command

I have 65536 real data points saved from an image. I have used reshape command to make square matrix. But result I am getting is 16 by 256 . Why is it so? Can I reconstruct the image ??

This is the .txt file http://m.uploadedit.com/b017/1372387722318.txt and code i used is

 a = load('fname.txt');
 y=reshape (a,256,256)

but instead of 256 by 256 it is showing 16 by 256

Best Answer

Dear sudipta,

I have downloaded your data file, and went like

a=load('1372387722318.txt');
y=reshape (a,256,256);
whos 
Name          Size              Bytes  Class     Attributes
a         65536x1              524288  double              
y           256x256            524288  double

and everything is just fine to me. So, the only possible error is that: you have another file with a name (fname.txt) in your directory which is not the same file you uploaded (1372387722318.txt). Check this out and I'm pretty sure you'll have it working.

Regards

Related Solutions

MATLAB: How to show an image from a textfile

jpg images are typically colour images. Colour images are stored as 3D arrays in matlab. dlmread and dlmwrite can only read 2D arrays so your serialisation to text loses that third dimension. All three pages are concatenated horizontally. In addition, jpg images are typically of type uint8, these values get cast to double without rescaling when you serialise them.

You can get back your original array by reshaping it back to 3D and casting it back to uint8:

readimage = dlmread('FileName23.txt');
readimage = uint8(reshape(readimage, size(readimage, 1), [], 3));
imshow(readimage);

Note that this applies to 8-bit colour jpg, which is the majority of jpg files. If the original jpg was 16-bit then you'd have to cast to uint16. If the original jpg was greyscale, you don't need the reshape.

MATLAB: ６７枚あるtifファイルの256×256の画像を256×256×67の三次元行列にしたいです

下記のようなコードで直接3次元配列に読み込んではいかがでしょうか。

手元に画像がないのでご自身の環境でお試しください。

また、 gray は同名の関数がありますので、変数としては使わないほうが無難です。

fileFolder = fullfile(pwd,'Series1'); % 画像の読込み (67枚の断面画像)
tifFiles = dir(fullfile(fileFolder,'*.tif'));
numfiles = length(tifFiles);
img = imread(tifFiles(1).name);
grayscale = zeros(size(img,1),size(img,2),numfiles);
for k = 2:numfiles
  grayscale(:,:,k) = imread(tifFiles(k).name); 
end

Best Answer

Related Solutions

MATLAB: How to show an image from a textfile

MATLAB: ６７枚あるtifファ​イルの256×256​の画像を256×25​6×67の三次元行列​にしたいです

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MATLAB: ６７枚あるtifファイルの256×256の画像を256×256×67の三次元行列にしたいです