How to find row and column of a pixel in an Image?

2011 3 21
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更新时间：2016 4 23
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Guys I want to find the rows and columns of pixels of image so that i can put that in if condition inside for loop. Bt i am unable to write that code. plz help me.

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I think you first have to clarify a litle your question, because you can use the coman [row,col]=find(variable==#) to find the pixel you want once you have the matrix of the pixel ( if it is not in truecolor). If you know the color of the pixel you just have to find the number that represent it in a scale (for instance 256 colors). I give this lines of a code I wrote recently to find the pixels in an images that are not totally white (in a scale of 256 colors.
[row,col]=find(Imagen~=255);
Radha r
Radha r 2016-4-23
how do find image row and coloumn pixel in matrix in train image because i would geetting the good and bad pixel find out
Image Analyst
Image Analyst 2016-4-23
Radha r, Start your own question and post your image and explain what "good" and "bad" means to you.

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Hi, what about this:
[ROWS,COLUMNS] = ndgrid(1:size(I,1),1:size(I,2));
ROWS = ROWS(:);
COLUMNS = COLUMNS(:);
where I is your image.
Best regards, Wolfgang

更多回答（3 个）

Karan Ratnaparkhi
Karan Ratnaparkhi 2011-3-21

0 个投票

Hi wolfgang I have an algorithm in which i am given a range of rows n columns lets say a to b (for rows) and c to d (for columns). now I hav to do operation only on those pixels which lie (whose rows n cols lie) in between a to b and c to d. Thats y i want to know how to get the row and column of given pixel (not the value of pixel.) Plz help me with this code.

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This sounds to me as if you want to perform some calculations within a subset of your image. Without knowing what exactly you want to do there, I suggest to take a look at the roi-based image processing section of the documentation.
http://www.mathworks.com/help/toolbox/images/ref/roifilt2.html
HTH, Wolfgang

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Syed Ali Hassan
Syed Ali Hassan 2014-2-22

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Check this [row_limit,col_limit]=size(img);

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Image Analyst
Image Analyst 2014-2-22
A bit risky and dangerous in general. See http://blogs.mathworks.com/steve/2011/03/22/too-much-information-about-the-size-function/ - Steve's blog. Unless you know for a fact in advance that the image is gray scale, you'll be safer and more robust if you do this:
% This works for grayscale and RGB images:
[rows, columns, numberOfColorChannels] = size(yourImage);
Radha r
Radha r 2016-4-23
it is not find the t my answer and what are you telling me i ont now please tell me example

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Radha r
Radha r 2016-4-23

0 个投票

it is not find the t my answer and what are you telling me i ont now please tell me example

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Image Analyst
Image Analyst 2016-4-23
Radha r, Start your own question and post your image and explain what "good" and "bad" means to you.

请先登录，再进行评论。

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