Is the .jpg image one-dimensional and two-dimensional?

part code:

validateattributes(I,{'uint8','uint16','uint32'},{'real','2d'}, ... mfilename, 'I',1);

Problem:

The .m file needs to input a .jpg image,when i use the .jpg image downloaded from the Source website,it worked.

But when i use the .jpg image from my camera,it showed below:

Error using demosaic

The first input required, I, should be two-dimensional.

Is the .jpg image one-dimensional and two-dimensional?

Answer 1

[Image Analyst]

JPG images are already demosaiced. I think you're using a raw image. Raw images usually are not demosaiced - they're just red, green, and blue pixels that are there, so no interpolation to fill in missing color values in the locations that didn't have a particular color pixel.

[Guillaume]

To add to IA's comment. The majoriy of jpeg images are colour images. When you read these in matlab you get a 3D matrix (height x width x 3 colour planes) and of course demosaic will refuse to work on them since it makes no sense.

Now, it's possible to save a raw image as jpeg, if you save it as a greyscale image (fairly uncommon) and lossless (which is a jpeg extension, so rarely used). In which case, you'd get a 2D matrix that you could indeed demosaic.

However, applying demosaic on any random image as you seem to be doing is meaningless. demosaic is meant to convert a colour camera sensor information (encoded using a Bayer pattern) into an image. If you already have an image, there's nothing to decode anymore.

[Huadong Hu]

this is the type i want,is it a 2D matrix that could demosaic (greyscale image )?

[Image Analyst]

This looks like a mosaiced image being displayed as a gray scale image, similar to the Mandi" image the Mathworks has used.

I = imread('mandi.tif');
J = demosaic(I,'bggr');
imshow(I);
figure;
imshow(J);

From the help:

RGB = demosaic(I,sensorAlignment)

Look into it.

[Guillaume]

Yes, it's probably a bayer image in 'bggr' format. However, as it has been saved as a lossy jpeg, the pattern has been irreparably damaged by the compression so it's unlikely that you'll get a proper colour image.

Don't use jpeg to save raw images.

[Umar Awan]

Hi @Image Analyst, sir i need your little help again. Please tell me how do i remove these line under the Urdu text. im working on my final year project , please do help sir. Thak You !!

[Image Analyst]

If it's part of your project, aren't you supposed to think up a way yourself?

[Walter Roberson]

That is an unrelated topic and should be a question of its own.

Answer 2

[KSSV]

If you have a RGB image it will be 3D matrix.

If you have a gray image it will be 1D matrix.

Try converting your image to gray.

I = imread(myimage) ; 
I = rgb2gray(I) ; 

[Huadong Hu]

how to use the code?add them to the demosaic.m file?