iOS如何扫描HEIF格式的二维码图片

一、说在前面

iphone 7 之后系统相机支持heif格式的图片，在扫描二维码时，该格式的图片需要转换成jpg格式才能进行扫描成功。

二、思路

用户在打开系统相册选择完一张照片后，要判断该照片是否是heif格式，如果是，进行格式转换之后再扫描jpg图片的内容，得到扫描结果。

三、具体实现

因为过程中用到photokit，因此需要加入该头文件，#import

@protocol tvuimagemanagerdelegate <nsobject>
- (void)letqrcodevcscanqrcodeimageinalbum:(bool)isheifformat;
@end

@interface tvuimagemanager : nsobject

@property (strong, nonatomic) uiimage *jpgimage;
@property (strong, nonatomic) uiimage *selectedimage;
@property (strong, nonatomic) phasset *selectedasset;
@property (nonatomic,strong) id <tvuimagemanagerdelegate> delegate;

+ (tvuimagemanager *)defaultmanager;
- (void)dosomethingafterselectedimage:(nsdictionary *)info;

@end

自定义类：（.mm）

#define ios9orlater ([uidevice currentdevice].systemversion.integervalue >= 9)

@implementation tvuimagemanager


#pragma mark - init part
+ (tvuimagemanager *)defaultmanager
{
  static tvuimagemanager *m_manager = nil;
  if (m_manager == nil) {
    m_manager = [[tvuimagemanager alloc] init];
  }
  return m_manager;
}

- (id)init
{
  self = [super init];
  if (self) {

  }
  return self;
}


#pragma mark - image format part
- (void)dosomethingafterselectedimage:(nsdictionary *)info
{
  [self getselectedimagephasset:info];
  if (self.selectedasset == nil) {
    log4cplus_error("tvuimagemanagerlog", "%s:selected image is null",__func__);
    return;
  }else {
    bool isheif = [self judgeifanimageisheifformat];
    if (isheif) {
      log4cplus_error("tvuimagemanagerlog", "%s:selected image is heif format",__func__);
      [self convertimageformatfromheiftojpegandthenscantheimage];
    }else {
      log4cplus_error("tvuimagemanagerlog", "%s:selected image is not heif format",__func__);
      self.selectedimage = (uiimage *)[info objectforkey:uiimagepickercontrolleroriginalimage];
      if (self.selectedimage == nil) {
        log4cplus_error("tvuimagemanagerlog", "%s:selected image is null",__func__);
        return;
      }
      [self.delegate letqrcodevcscanqrcodeimageinalbum:no];
    }
  }
}

// choose a picture from the system album
- (void)getselectedimagephasset:(nsdictionary *)info
{
  log4cplus_error("tvuimagemanagerlog", "%s:get selected image phasset",__func__);
  nsurl *imageasseturl = [info objectforkey:uiimagepickercontrollerreferenceurl];
  phfetchresult *fetchresult = [phasset fetchassetswithalasseturls:[nsarray arraywithobject:imageasseturl] options:nil];
  if (fetchresult.count == 0) {
    log4cplus_error("tvuimagemanagerlog", "%s:fetchresult's count is 0",__func__);
    return;
  }
  self.selectedasset = (phasset*)fetchresult.firstobject;
}

// determine if the picture is in heif format
- (bool)judgeifanimageisheifformat
{
  log4cplus_error("tvuimagemanagerlog", "%s:begin to judge if an image is heif format",__func__);
  __block bool isheif = no;
  if (ios9orlater) {
    nsarray *resourcelist = (nsarray *)[phassetresource assetresourcesforasset:self.selectedasset];
    [resourcelist enumerateobjectsusingblock:^(id _nonnull obj, nsuinteger idx, bool * _nonnull stop) {
      phassetresource *resource = obj;
      nsstring *uti = resource.uniformtypeidentifier;
      if ([uti isequaltostring:@"public.heif"] || [uti isequaltostring:@"public.heic"]) {
        isheif = yes;
        *stop = yes;
      }
    }];
  }else {
    nsstring *uti = [self.selectedasset valueforkey:@"uniformtypeidentifier"];
    isheif = [uti isequaltostring:@"public.heif"] || [uti isequaltostring:@"public.heic"];
  }
  return isheif;
}

// convert image format from heif to jpeg and then scan the image
- (void)convertimageformatfromheiftojpegandthenscantheimage
{
  log4cplus_error("tvuimagemanagerlog", "%s:begin to convert image format from heif to jpeg",__func__);
  [[phimagemanager defaultmanager] requestimagedataforasset:self.selectedasset options:nil resulthandler:^(nsdata * _nullable imagedata, nsstring * _nullable datauti, uiimageorientation orientation, nsdictionary * _nullable info) {
    ciimage *ciimage = [ciimage imagewithdata:imagedata];
    cicontext *context = [cicontext context];
    nsdata *jpgdata = [context jpegrepresentationofimage:ciimage colorspace:ciimage.colorspace options:@{}];
    self.jpgimage = [uiimage imagewithdata:jpgdata];
    [self.delegate letqrcodevcscanqrcodeimageinalbum:yes];
  }];
}

@end

调用：

#pragma mark uiimagepickercontrollerdelegate
- (void)imagepickercontroller:(uiimagepickercontroller *)picker didfinishpickingmediawithinfo:(nsdictionary *)info
{
  [self.imagemgr dosomethingafterselectedimage:info];
}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。