YYXC_Coach/JSJPCoach/Category/UIImage+resize.m

//
//  UIImage+resize.m
//  test23
//
//  Created by apple on 15/12/1.
//  Copyright (c) 2015年 JCZ. All rights reserved.
//

#import "UIImage+resize.h"

@implementation UIImage(resize)

//将JPEG格式转换为PNG
-(UIImage *)reduceImage:(UIImage *)image percent:(float)percent
{
    NSData *imageData = UIImageJPEGRepresentation(image, percent);
    UIImage *newImage = [UIImage imageWithData:imageData];
    return newImage;
}
//压缩图片尺寸
- (UIImage *)scaledToSize:(CGSize)newSize
{
    //首先要找到缩放比 按长的适配 不足的部分空白
    CGFloat rate =newSize.width*1.0/ self.size.width ;
    if (self.size.height* rate > newSize.height) {
        //过长了。
        rate =newSize.height*1.0/ self.size.height ;
    }
    CGSize size = CGSizeMake(self.size.width*rate, self.size.height*rate);
    
    // Create a graphics image context
    UIGraphicsBeginImageContext(size);
    // new size
    [self drawInRect:CGRectMake(0,0,size.width,size.height)];
    // Get the new image from the context
    UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
    
    // End the context
    UIGraphicsEndImageContext();
    // Return the new image.
    return newImage;
}

- (UIImage *)scaledAndCutToSize:(CGSize)newSize{
    
    //首先要找到缩放比 按短的适配 长的部分裁减掉
    CGFloat rate =newSize.width*1.0/ self.size.width ;
    if (self.size.height* rate < newSize.height) {
        //过长了。
        rate =newSize.height*1.0/ self.size.height ;
    }
    CGSize size = CGSizeMake(self.size.width*rate, self.size.height*rate);
    
    UIGraphicsBeginImageContext(size);
    
    [self drawInRect:CGRectMake(0,0,size.width,size.height)];
    // Get the new image from the context
    UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
    
    // End the context
    UIGraphicsEndImageContext();
    // Return the new image.
    return newImage;
}

@end