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亿速云。
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