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Asked by LOKESH on 31 Jan 2012

I have a 2d NxN image L. I need to convert it to a sequence of pixels L1={k1,k2,....kNxN} row wise

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Answer by Walter Roberson on 31 Jan 2012

Accepted answer

L1 = reshape(L.',1,[]).'

Show 4 older comments

Walter Roberson on 1 Feb 2012

Experiment with these steps:

L = magic(5)

t1 = L.'

t2 = t1(:)

t3 = t2.'

And see http://www.mathworks.com/help/techdoc/math/f1-85462.html#f1-85511

LOKESH on 4 Feb 2012

Thanks Sir.But with L1 = reshape(L.',1,[]),I am able to convert my 1D image to 2D.But it works only for some images,for rest it gives me errors of

"Access Out of Bounds" OR

"??? Error using ==> reshape

Product of known dimensions, 256, not divisible into total number

of elements, 21845.

Error in ==> rk4_CHEN at 198

C2 = reshape(C1.',M,[]);"

Walter Roberson on 4 Feb 2012

You are using M = 256. The only way to reshape in to a 1D row of pixels row-wise is if M = 1.

If you want to convert in to rows, then the number of rows you use, M, must be divide the number of elements in the matrix.

I notice that 21845, the number of elements in the matrix, is 257 x 85. 257 is, of course, one greater than 256. Please check your code for an off-by-one error.

Also, please be careful about whether you use M as the 2nd or 3rd parameter of the reshape(). Do you want M rows and however many columns that works out to, or do you want M columns and however many rows that works out to?

Anyhow, as your requirements have changed since your initial question, please post your new requirements.

Answer by Derek O'Connor on 31 Jan 2012

L1 = L(:)'

Walter Roberson on 31 Jan 2012

That would not take the sequence "row-wise"; it would take them column-wise.

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