can I take pca analysis of columns extracted from pixel values of a converted to gray image?

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Neo 2023-1-19

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评论： Image Analyst 2023-1-21

starting columns and ending columns

I made a code that outputs the pixel values of the columns from an image.

meanpixelvalues(i) = meanpixelvalues(binaryImage(masks));

I then applied pca analysis to the pixel values and the pca code output 1:

coeff = pca(meanpixelvalues(i))

Results:

coeff =

but I don't think that's physically possible and i'm wondering what did i do wrong to get a value of 1 and what does the columns of an image mean?

Thank you.

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Neo 2023-1-20

@Chris

StartingColumns =

Columns 1 through 7

1 435 869 1303 1737 2171 2605

Columns 8 through 13

3039 3473 3907 4341 4775 5209

endingColumns =

Columns 1 through 7

434 868 1302 1736 2170 2604 3038

Columns 8 through 12

3472 3906 4340 4774 5208

Neo 2023-1-20

rows =

1452

columns =

5208

@Chris

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Image Analyst 2023-1-20

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pca_image.m

You can do it. I attach an example where I did it for an RGB image where each column was one of the color channels converted into a column vector. But if your variables (features) are individual channels of a gray scale image, like you said, it's difficult to interpret. Why do you want to do it if you don't know what the PCs would represent?

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Neo 2023-1-20

sorry I attached the wrong image. But I think my main question is how to extract pc from an image that can be plotted on a graph not from color channels.