uiimagejpegrepresentation

问题 On iOS 4.2 when I use UIImagePickerController to let the user select a image from the photo library these are the dictionary keys that are returned to me: 2011-03-02 13:15:59.518 xxx[15098:307] didFinishPickingMediaWithInfo: info dictionary: { UIImagePickerControllerMediaType = "public.image"; UIImagePickerControllerOriginalImage = "<UIImage: 0x3405d0>"; UIImagePickerControllerReferenceURL = "assets-library://asset/asset.JPG?id=1000000050&ext=JPG"; } Using one or more of these keys, how can I

问题 I am new to iphone, Is it possible to upload uiimage on server without using any php or other files. I got may examples of uploading image by sending request to some php file. But i don't wants to use php files. I have server path and Upload folder on server. Can Anyone has solution to upload image on server with only using iphone ?? Any Idea is greatly appreciated. 回答1: Where are you uploading a photo to? There needs to be a server side script to receive the file, typically a PHP, Perl, or

问题 I would like to apply a filter to a photo from the user's library then write it back to disk. I'm using UIImageJPEGRepresentation . This function takes a UIImage and a compressionQuality value between 0.0 and 1.0. Because I want to preserve the original quality, I set it to 1.0. But I found this actually creates an image file that's larger in file size than the original, somewhat significantly larger even. I noticed in Apple's Sample Photo Editing Extension app they always set the quality to

问题 I'm currently making a photo editing app. When a photo is selected by the user, it is automatically converted into black and white using this code: func blackWhiteImage(image: UIImage) -> Data { print("Starting black & white") let orgImg = CIImage(image: image) let bnwImg = orgImg?.applyingFilter("CIColorControls", withInputParameters: [kCIInputSaturationKey:0.0]) let outputImage = UIImage(ciImage: bnwImg!) print("Black & white complete") return UIImagePNGRepresentation(outputImage)! } The

问题 I am trying to save an image coming from the iPhone camera to a file. I use the following code: try UIImageJPEGRepresentation(toWrite, 0.8)?.write(to: tempURL, options: NSData.WritingOptions.atomicWrite) This results in a file double the resolution of the toWrite UIImage. I confirmed in the watch expressions that creating a new UIImage from UIImageJPEGRepresentation doubles its resolution -> toWrite.size CGSize (width = 3264, height = 2448) -> UIImage(data: UIImageJPEGRepresentation(toWrite,

问题 I am trying to take a screenshot/snapshot of a UIView. I am able to get the a screenshot with the code below of the current visible view - but i am after the whole view. The view is a scrollview so there is content below that isnt visible that i would like to be included How do i extend this code to take into account the view that isnt visible? UIGraphicsBeginImageContext(activityView.frame.size); [self.activityView.layer renderInContext:UIGraphicsGetCurrentContext()]; UIImage *fullScreenshot

问题 I am creating a multipart image data upload request. i am getting NSData from UIImage by UIImageJPEGRepresentation but when i try to convert the data into string i am getting nil value i have followed this link to convert NSData to NSString Convert UTF-8 encoded NSData to NSString here is my code :- NSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@", boundary]; [request addValue:contentType forHTTPHeaderField:@"Content-Type"]; NSMutableString *body =

问题 I am a relatively new iOS developer. I am attempting to build an app that uploads images to a server. However, when I get the image with metadata, the orientation is always off. Here is the code I am using: - (void)getJPEGFromAssetForURL:(NSURL *)url { ALAssetsLibrary* assetslibrary = [[ALAssetsLibrary alloc] init]; [assetslibrary assetForURL:url resultBlock: ^(ALAsset *myasset) { self.rep = [myasset defaultRepresentation]; NSLog(@"getJPEGFromAssetForURL: default asset representation for %@:

问题 I've read uiimagepickercontroller uiimage memory and more and other relevant questions, but I can't get my head around one thing, and I wonder if there are people around here with experience on this particular aspect. In my app I let the user select an image from his library, ultimately resulting in an upload. (An interesting thing here, is that the images in there may originate from 12-megapixel high quality camera's, since e.g. iTunes happily syncs them into the phone.) For various reasons,

问题 I'm working with PhotoKit and have implemented filters users can apply to photos in their Photo Library. I am currently obtaining the image, applying a filter, returning the edited version as a CIImage , then I convert the CIImage into NSData using UIImageJPEGRepresentation so I may write that out to disk. While this works beautifully, when users attempt to edit really large (like 30 MB) photos it can take upwards of 30 seconds for this to occur, with 98% of the time spent on