iOS 指定压缩大小(UIImage扩张)--Swift/OC版

//
//  UIImageExtension.swift
//  GongFuBaoSwift
//
//  Created by GongHui_YJ on 16/8/12.
//  Copyright © 2016年 杨建. All rights reserved.
//
//                            _ooOoo_
//                           o8888888o
//                           88" . "88
//                           (| -_- |)
//                            O\ = /O
//                        ____/`---'\____
//                      .   ' \\| |// `.
//                       / \\||| : |||// \
//                     / _||||| -:- |||||- \
//                       | | \\\ - /// | |
//                     | \_| ''\---/'' | |
//                      \ .-\__ `-` ___/-. /
//                   ___`. .' /--.--\ `. . __
//                ."" '< `.___\_<|>_/___.' >'"".
//               | | : `- \`.;`\ _ /`;.`/ - ` : | |
//                 \ \ `-. \_ __\ /__ _/ .-` / /
//         ======`-.____`-.___\_____/___.-`____.-'======
//                            `=---='
//
//         .............................................
//                  佛祖保佑             永无BUG
//          佛曰:
//                  写字楼里写字间，写字间里程序员；
//                  程序人员写程序，又拿程序换酒钱。
//                  酒醒只在网上坐，酒醉还来网下眠；
//                  酒醉酒醒日复日，网上网下年复年。
//                  但愿老死电脑间，不愿鞠躬老板前；
//                  奔驰宝马贵者趣，公交自行程序员。
//                  别人笑我忒疯癫，我笑自己命太贱；
//                  不见满街漂亮妹，哪个归得程序员？
import Foundation

extension UIImage {

///对指定图片进行拉伸
func resizableImage(name: String) -> UIImage {

var normal = UIImage(named: name)!
let imageWidth = normal.size.width * 0.5
let imageHeight = normal.size.height * 0.5
normal = resizableImageWithCapInsets(UIEdgeInsetsMake(imageHeight, imageWidth, imageHeight, imageWidth))

return normal
}

/**
*  压缩上传图片到指定字节
*
*  image     压缩的图片
*  maxLength 压缩后最大字节大小
*
*  return 压缩后图片的二进制
*/
class func compressImage(image: UIImage, maxLength: Int) -> NSData? {

let newSize = self.scaleImage(image, imageLength: 300)
let newImage = self.resizeImage(image, newSize: newSize)

var compress:CGFloat = 0.9
var data = UIImageJPEGRepresentation(newImage, compress)

while data?.length > maxLength && compress > 0.01 {
compress -= 0.02
data = UIImageJPEGRepresentation(newImage, compress)
}

return data
}

/**
*  通过指定图片最长边，获得等比例的图片size
*
*  image       原始图片
*  imageLength 图片允许的最长宽度（高度）
*
*  return 获得等比例的size
*/
class func scaleImage(image: UIImage, imageLength: CGFloat) -> CGSize {

var newWidth:CGFloat = 0.0
var newHeight:CGFloat = 0.0
let width = image.size.width
let height = image.size.height

if (width > imageLength || height > imageLength){

if (width > height) {

newWidth = imageLength;
newHeight = newWidth * height / width;

}else if(height > width){

newHeight = imageLength;
newWidth = newHeight * width / height;

}else{

newWidth = imageLength;
newHeight = imageLength;
}

}
return CGSize(width: newWidth, height: newHeight)
}

/**
*  获得指定size的图片
*
*  image   原始图片
*  newSize 指定的size
*
*  return 调整后的图片
*/
class func resizeImage(image: UIImage, newSize: CGSize) -> UIImage {
UIGraphicsBeginImageContext(newSize)
image.drawInRect(CGRect(x: 0, y: 0, width: newSize.width, height: newSize.height))

let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()

return newImage
}

}

/**
*  图片压缩
*/
- (NSData *)resetSizeOfImageData:(UIImage *)source_image maxSize:(NSInteger)maxSize
{
//先调整分辨率
CGSize newSize = CGSizeMake(source_image.size.width, source_image.size.height);

CGFloat tempHeight = newSize.height / 1024;
CGFloat tempWidth = newSize.width / 1024;

if (tempWidth > 1.0 && tempWidth > tempHeight) {
newSize = CGSizeMake(source_image.size.width / tempWidth, source_image.size.height / tempWidth);
}
else if (tempHeight > 1.0 && tempWidth < tempHeight){
newSize = CGSizeMake(source_image.size.width / tempHeight, source_image.size.height / tempHeight);
}

UIGraphicsBeginImageContext(newSize);
[source_image drawInRect:CGRectMake(0,0,newSize.width,newSize.height)];
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

//调整大小
NSData *imageData = UIImageJPEGRepresentation(newImage,1.0);
NSUInteger sizeOrigin = [imageData length];
NSUInteger sizeOriginKB = sizeOrigin / 1024;
if (sizeOriginKB > maxSize) {
NSData *finallImageData = UIImageJPEGRepresentation(newImage,0.50);
return finallImageData;
}

return imageData;
}