X, Y position in an image after resize.

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Hello, if I have a position (x, y) in an image, that is inside a picturebox,
how can I know the same position if i change the size of the image?
Thank you very much.re>

I will try to explain better what I need to do:
On an image (which is a plane) I want to mark a red dot where a fire detector goes.
That doing click with the mouse.
I take and store coordinates (x, y) so that each time that plane is shown (there are many) place each sensor in its place.
My problem is that if I change the size of the picturebox (sizemode = StretchImage) those coordinates are no longer valid. Thanks for answering so fast

What I have tried:

Get a position (x, y) that does not change if you change the size of an image.

Posted 11-Jul-18 1:19am

Sergio Bombien

Updated 11-Jul-18 22:17pm

v2

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F-ES Sitecore 11-Jul-18 7:25am

Should just be basic maths. Work out the x coord as a percentage of the width. So if the image is 50 wide and x is 10, that is 20% (100/width * x). So if the image is changed to be 100 wide, 20% of 100 is 20 so that's your new x. If the image is shrunk to 25 then 20% of 25 is 5 so that's your new x. Do the same thing with y.

Sergio Bombien 13-Jul-18 3:46am

Thank you very much, I'm a little rusty with the math.

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#realJSOP · Answer 1 · 2018-07-11T04:08:00

Solution 1

Handle the resize event for the image control, and recalculate the desired coordinate(s) based on the change ratio for both sides of the image.

Posted 11-Jul-18 4:08am

#realJSOP

Patrice T · Answer 2 · 2018-07-11T09:58:00

Quote:
Hello, if I have a position (x, y) in an image, that is inside a picturebox,
how can I know the same position if i change the size of the image?

It is really simple maths.
First solution: get a real picture, spot a particular point measure its position in picture, make a copy with a change of size, and measure new position.
Compare old size and new size, old position and new position, find the maths.

Second solution: your problem and the maths are the same as:
you are a cashier and you earn 3 cents for every dollar you bill.
How much do you earn if you bill $10, $50, $100 ...