ios/Timi/Class/Base/Utils/ImageHandler/ImageHandlerObject.m

//
//  ImageHandlerObject.m
//  MIT_Shop
//
//  Created by 翟玉磊 on 2018/1/26.
//  Copyright © 2018年 翟玉磊. All rights reserved.
//

#import "ImageHandlerObject.h"

#define KCompressibilityFactor 1280.0f

@implementation ImageHandlerObject

+ (UIImage *)compressImage:(UIImage *)image toByte:(NSUInteger)maxLength {
    // Compress by quality
    CGFloat compression = 1;
    NSData *data = UIImageJPEGRepresentation(image, compression);
    if (data.length < maxLength) return image;
    
    CGFloat max = 1;
    CGFloat min = 0;
    for (int i = 0; i < 6; ++i) {
        compression = (max + min) / 2;
        data = UIImageJPEGRepresentation(image, compression);
        if (data.length < maxLength * 0.9) {
            min = compression;
        } else if (data.length > maxLength) {
            max = compression;
        } else {
            break;
        }
    }
    UIImage *resultImage = [UIImage imageWithData:data];
    if (data.length < maxLength) {
        return resultImage;
    }
    
    // Compress by size
    NSUInteger lastDataLength = 0;
    while (data.length > maxLength && data.length != lastDataLength) {
        lastDataLength = data.length;
        CGFloat ratio = (CGFloat)maxLength / data.length;
        CGSize size = CGSizeMake((NSUInteger)(resultImage.size.width * sqrtf(ratio)),
                                 (NSUInteger)(resultImage.size.height * sqrtf(ratio))); // Use NSUInteger to prevent white blank
        UIGraphicsBeginImageContext(size);
        [resultImage drawInRect:CGRectMake(0, 0, size.width, size.height)];
        resultImage = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();
        data = UIImageJPEGRepresentation(resultImage, compression);
    }
    
    return resultImage;
}

#pragma mark - 压缩一张图片 最大宽高1280 类似于微信算法
+ (UIImage *)getJPEGImagerImg:(UIImage *)image{
    
    CGFloat oldImg_WID = image.size.width;
    CGFloat oldImg_HEI = image.size.height;
    //CGFloat aspectRatio = oldImg_WID/oldImg_HEI;//宽高比
    if(oldImg_WID > KCompressibilityFactor || oldImg_HEI > KCompressibilityFactor){
        //超过设置的最大宽度 先判断那个边最长
        if(oldImg_WID > oldImg_HEI){
            //宽度大于高度
            oldImg_HEI = (KCompressibilityFactor * oldImg_HEI)/oldImg_WID;
            oldImg_WID = KCompressibilityFactor;
        }else{
            oldImg_WID = (KCompressibilityFactor * oldImg_WID)/oldImg_HEI;
            oldImg_HEI = KCompressibilityFactor;
        }
    }
    UIImage *newImg = [self imageWithImage:image scaledToSize:CGSizeMake(oldImg_WID, oldImg_HEI)];
    NSData *dJpeg = nil;
    if (UIImagePNGRepresentation(newImg)==nil) {
        dJpeg = UIImageJPEGRepresentation(newImg, 0.5);
    }else{
        dJpeg = UIImagePNGRepresentation(newImg);
    }
    return [UIImage imageWithData:dJpeg];
}

#pragma mark - 压缩多张图片 最大宽高1280 类似于微信算法
+ (NSArray *)getJPEGImagerImgArr:(NSArray *)imageArr{
    NSMutableArray *newImgArr = [NSMutableArray new];
    for (int i = 0; i<imageArr.count; i++) {
        UIImage *newImg = [self getJPEGImagerImg:imageArr[i]];
        [newImgArr addObject:newImg];
    }
    return newImgArr;
}
#pragma mark - 压缩一张图片 自定义最大宽高
+ (UIImage *)getJPEGImagerImg:(UIImage *)image compressibilityFactor:(CGFloat)compressibilityFactor{
    CGFloat oldImg_WID = image.size.width;
    CGFloat oldImg_HEI = image.size.height;
    //CGFloat aspectRatio = oldImg_WID/oldImg_HEI;//宽高比
    if(oldImg_WID > compressibilityFactor || oldImg_HEI > compressibilityFactor){
        //超过设置的最大宽度 先判断那个边最长
        if(oldImg_WID > oldImg_HEI){
            //宽度大于高度
            oldImg_HEI = (compressibilityFactor * oldImg_HEI)/oldImg_WID;
            oldImg_WID = compressibilityFactor;
        }else{
            oldImg_WID = (compressibilityFactor * oldImg_WID)/oldImg_HEI;
            oldImg_HEI = compressibilityFactor;
        }
    }
    UIImage *newImg = [self imageWithImage:image scaledToSize:CGSizeMake(oldImg_WID, oldImg_HEI)];
    NSData *dJpeg = nil;
    if (UIImagePNGRepresentation(newImg)==nil) {
        dJpeg = UIImageJPEGRepresentation(newImg, 0.5);
    }else{
        dJpeg = UIImagePNGRepresentation(newImg);
    }
    return [UIImage imageWithData:dJpeg];
}
#pragma mark - 压缩多张图片 自定义最大宽高
+ (NSArray *)getJPEGImagerImgArr:(NSArray *)imageArr compressibilityFactor:(CGFloat)compressibilityFactor{
    NSMutableArray *newImgArr = [NSMutableArray new];
    for (int i = 0; i<imageArr.count; i++) {
        UIImage *newImg = [self getJPEGImagerImg:imageArr[i] compressibilityFactor:compressibilityFactor];
        [newImgArr addObject:newImg];
    }
    return newImgArr;
}
#pragma mark - 根据宽高压缩图片
+ (UIImage *)imageWithImage:(UIImage *)image scaledToSize:(CGSize)newSize{
    UIGraphicsBeginImageContext(newSize);
    [image drawInRect:CGRectMake(0,0,newSize.width,newSize.height)];
    UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return newImage;
}
@end