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: %snout: %sncompress: %snsuccessn",argv[1],argv[2],argv[3]);
        }else         {
            printf("failure!n");
        }
        return ret;