ios mac 对照片进行JPEG压缩

    UIImage *timg = [UIImage imageWithContentsOfFile:@"/Users/cc/Desktop/testiOS/IMG_0420.PNG"];
    for (int i = 0; i <10; i++) {
        NSData *cd = UIImageJPEGRepresentation(timg, (i+1)/10.0f);
        [cd writeToFile:[NSString stringWithFormat:@"/Users/cc/Desktop/testiOS/com%.1f.jpeg",(i+1)/10.0f] atomically:YES];
    }

            //
            参数校验
            if (argc!=4) {
            printf("参数错误，请检测！\n");
            printf("本程序主要是对图片进行JPEG压缩\n");
            printf("示例：./JPEGCompress /xxpath/imgfile /xxpath/out.jpeg 0.4 \n");
            printf("参数一：要压缩的图片；参数二：输出路径；参数三：压缩比0.1～1.0之间\n");
            
            return -1000;
        }
    
        NSString *inPath = [NSString stringWithCString:argv[1] encoding:NSUTF8StringEncoding];
        NSString *outPath = [NSString stringWithCString:argv[2] encoding:NSUTF8StringEncoding];
        float compress =  [[NSString stringWithCString:argv[3] encoding:NSUTF8StringEncoding] floatValue];
        
        NSImage *simg = [[NSImage alloc]initWithContentsOfFile:inPath];
        NSData *imgDt = [simg TIFFRepresentation];
        NSBitmapImageRep *imageRep = [NSBitmapImageRep imageRepWithData:imgDt];
        NSDictionary *imageProps = [NSDictionary dictionaryWithObject:[NSNumber numberWithFloat:compress] forKey:NSImageCompressionFactor];
        imgDt = [imageRep representationUsingType:NSJPEGFileType properties:imageProps];
        
        int ret = [imgDt writeToFile:outPath atomically:YES];
        if (ret>0) {
            printf("in: %s\nout: %s\ncompress: %s\nSUCCESS\n",argv[1],argv[2],argv[3]);
        }else
        {
            printf("FAILURE!\n");
        }
        return ret;