压缩前图片
压缩前占用内存
压缩后图片
压缩后占用内存
压缩前后图片大小对比
class PictureUtil: NSObject {
//尺寸压缩
static func compress(image:UIImage,reWidth:CGFloat,reHeight:CGFloat)->NSData{
UIGraphicsBeginImageContext(CGSizeMake(reWidth, reHeight))
image.drawInRect(CGRectMake(0, 0, reWidth, reHeight))
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
var inSameSize = getInSameSize(image, reWidth: reWidth, reHeight: reHeight)
//如果尺寸没有超过 那么这里做些压的操作
if inSameSize == 1.0{
inSameSize = 0.7
}
return UIImageJPEGRepresentation(newImage, inSameSize)!
}
//获取体积缩放比例
private static func getInSameSize(image:UIImage,reWidth:CGFloat,reHeight:CGFloat)->CGFloat{
var insameSize:CGFloat = 1.0
let width = image.size.width
let height = image.size.height
if (width > reWidth || height > reHeight){
let halfWidth = width / 2
let halfHeight = height / 2
while ((halfWidth * insameSize) > reWidth && (halfHeight*insameSize) > reHeight){
insameSize/=2
}
}
return insameSize
}
}
