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mathscalingimage-scaling

Scaling images to an area

I'm trying to scale a bunch of images so that they have the same area, but keep their aspect ratio, but am having trouble find a formula to do so.

Does anyone know a formula?

Solution

  • For a given area A,

    newx * newy = A
newx / newy = oldx / oldy

    which gives you:

    newy = A / newx
newy = newx / (oldx / oldy)

A / newx = newx / (oldx / oldy)
A * oldx / oldy = newx ^ 2

    which then solves to:

    newx = sqrt(A * oldx / oldy)
newy = A / newx

    Then again, this is a maths question, not a programming one...