Image scaling by Width & Height constant

Image scaling by Width & Height constant - preserve aspect ratio

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Farce Milverk - 17 Jul 2006 18:18 GMT

Hi,

I'm looking for an algorithm to resize an image of arbitrary size to a
"fixed" / required width and height.

For example, my application requires that images be no larger than 440 pixel
(height) x 780 (wide)

So the "preferred size" would be 440 x 780

If an image is too large, either by width or height it should be resized
until less than or equal to 440 x 780 and preserve aspect ratio.

Thanks for any tips.

Farce

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Sigmund Hansen - 18 Jul 2006 00:36 GMT

> Hi,
>
[quoted text clipped - 12 lines]
>
> Farce

Ok,
if the ratio is lower than 780/440 (your fixed width split on the fixed
height), then you need to resize by height, if it is (equal to
or(equality can be put in either one of the two methods)) higher than
this one, then it should be resized by width...
So:

double fixedRatio = 780.0/440.0;
if((double)image.getWidth()/image.getHeight >= fixedRatio)
{
resizeImage( image, 780, image.getHeight()/(image.getWidth()/780.0) );
// This requires that there exists a resizeImage method, but I don't
know what you want, drawImage or if you are making a file or what, so
this is kind of pseudo-code.
}
else
{
resizeImage( image, image.getWidth()/(image.getHeight()/440.0), 440);
}

I think that should do it, but I'm kind of tired right now...

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Image scaling by Width & Height constant - preserve aspect ratio

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