Algorithm to resize image and maintain aspect ratio to fit iPhone

Question

I\'m creating a web service for an iPhone app to interact with.

When my client uploads images server-side, I want my php script to resize the image, whilst m

Answer 1

Maybe a slightly shorter routine would be:

// Calculate resize ratios for resizing 
float ratioW = targetWidth / oldWidth; 
float ratioH = targetHeight / oldHeight;

// smaller ratio will ensure that the image fits in the view
float ratio = ratioW < ratioH?ratioW:ratioH;

newWidth = oldWidth*ratio;
newHeight = oldHeight*ratio;

Obviously if the ratio is > 1, then it's enlarging, if < 1 then it's shrinking.