How To Properly Compress UIImages At Runtime

Question

I need to load 4 images for simultaneous editing. When I load them from the users library, the memory exceeds 500mb and crashes.

Here is a log from a raw allocations

Answer 1

I ended up hard coding a size reduction before processing the image. Here is the code:

PHImageManager.defaultManager().requestImageForAsset(asset, targetSize:CGSizeMake(CGFloat(asset.pixelWidth), CGFloat(asset.pixelHeight)), contentMode: .AspectFill, options: options)
{
  result, info in
  var minRatio:CGFloat = 1
  //Reduce file size so take 1/2 UIScreen.mainScreen().bounds.width/2 || CGFloat(asset.pixelHeight) > UIScreen.mainScreen().bounds.height/2)
  {
    minRatio = min((UIScreen.mainScreen().bounds.width/2)/(CGFloat(asset.pixelWidth)), ((UIScreen.mainScreen().bounds.height/2)/CGFloat(asset.pixelHeight)))
  }

  var size:CGSize = CGSizeMake((CGFloat(asset.pixelWidth)*minRatio),(CGFloat(asset.pixelHeight)*minRatio))
  UIGraphicsBeginImageContextWithOptions(size, false, 0.0)
  result.drawInRect(CGRectMake(0, 0, size.width, size.height))
  var final = UIGraphicsGetImageFromCurrentImageContext()
  var image = iImage(uiimage: final)
}