how can i make a change in my image ?

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hamed 2014-9-1

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https://ww2.mathworks.cn/matlabcentral/answers/153061-how-can-i-make-a-change-in-my-image

评论： Image Analyst 2014-9-3

matlab.mat

hi guys . i have an image (257*161) .

im = f(x,y)

how can i change my image equation to im = f(x/8 , y/12 )

could you please help me ?

thanks

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Stephen23 2014-9-1

编辑：Stephen23 2014-9-1

I downloaded your file matlab.mat , and using the MATLAB function image it created a lovely figure showing some torso cross-section, like from a CT scan.

What is the problem with the image? What exactly do you mean by "image equation"? What is the function f ? What are the variables x and y ? How should the image be different?

Do you wish to scale, resize or skew the image?

hamed 2014-9-1

编辑：hamed 2014-9-1

在 MATLAB Online 中打开

Hi i want to do scale and translation normalization

i read in a site :

 p(x/a+x1,y/a+x2) to p(x,y),where p(x,y) is original image, x1 and x2 are the centroid of p(x,y),x1=m10/m00,x2=m01/m00,a=sqrt(β/m00),β is a predetermined value. In fact, this is doing scale and translation normalization

i computed m= a+x1 and n=a+x2 . now how can i compute P(x/m , y/n)??

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Answer 1

Image Analyst 2014-9-1

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https://ww2.mathworks.cn/matlabcentral/answers/153061-how-can-i-make-a-change-in-my-image#answer_150378

在 MATLAB Online 中打开

Do you possibly mean imresize()?

[rows, columns, numberOfColorChannels] = size(im);
% Get new x-width and y-height using formulas x/8 , y/12
% Remember, arrays are (rows, columns) = (y, x) NOT (x,y)!!!!!!!!!!
newRows = round(rows/12); % New y height
newColumns = round(columns / 8); % New x width
% Resize image
resizedImage = imresize(im, [newRows, newColumns]);

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hamed 2014-9-3

编辑：hamed 2014-9-3

在 MATLAB Online 中打开

thanks a lot for you answer and attention

i read some paper about Zernike moment and scale invariant problem. some of them solve it with this method :

 image MUST first be normalized w.r.t. scale and translation
    i.e. centroid of image is at image center, and image
    has geometrical moment m00 = fixed number/scale

M00: sum of grey level (for greytone images)

or in another text i read

Moments η i j where i + j ≥ 2 can be constructed to be invariant to both translation and changes in scale by dividing the corresponding central moment by the properly scaled (00)th moment, using the following formula.

http://en.wikipedia.org/wiki/Image_moment

i want to write these equation in matlab and change my image scale with this equations but i don't know could you please help me ??