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
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@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
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自定义类:(.mm)
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#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
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调用:
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#pragma mark UIImagePickerControllerDelegate
- ( void )imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
[self.imageMgr doSomethingAfterSelectedImage:info];
}
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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服务器之家。
原文链接:http://blog.csdn.net/GZgengzhen/article/details/79401639