Hi I'm using IOS swift 3 to let user pick images from library or album.I have an UIImage variable.How can we use property Observer to update the UIImage when user finished pick an Image
Some thing like
var image: UIImage = {
didSet....
}
Currently I'm doing this
func show(image: UIImage) {
imageView.image = image
imageView.isHidden = false
imageView.frame = CGRect(x: 10, y: 10, width: 260, height: 260)
addPhotoLabel.isHidden = true
}
func imagePickerController(_ picker: UIImagePickerController,
didFinishPickingMediaWithInfo info: [String : Any]) {
image = info[UIImagePickerControllerEditedImage] as? UIImage
if let theImage = image {
show(image: theImage)
}
dismiss(animated: true, completion: nil)
}
Thinking of using property Observer to improve the approach.Any help is much appreciate.Thanks!
If you really want to update the image view any time the image property is set, then simply put all of the code in your show method in the didSet block for the image property.
var image: UIImage = {
didSet {
imageView.image = image
imageView.isHidden = false
imageView.frame = CGRect(x: 10, y: 10, width: 260, height: 260)
addPhotoLabel.isHidden = true
}
}
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
if let theImage = info[UIImagePickerControllerEditedImage] as? UIImage {
image = theImage
}
picker.dismiss(animated: true, completion: nil)
}
Related
I have an app where the user presses a button and takes a photo, then the photo goes to ImageAnnotation class and it must be added to the map, but I get such an error: "Unexpectedly found while implicitly unwrapping the optional"
Only this error prevents the app to work correctly, if You can help me I would appreciate that highly
So here is the code
extension MapViewController: UIImagePickerControllerDelegate, UINavigationControllerDelegate {
func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
picker.dismiss(animated: true, completion: nil)
}
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
picker.dismiss(animated: true, completion: nil)
guard let ecoImage = info[UIImagePickerController.InfoKey.originalImage] as? UIImage else { return }
guard let currentLocation = locationManager.location else { return }
let pin = ImageAnnotation(coordinate: CLLocationCoordinate2D(latitude: currentLocation.coordinate.latitude, longitude: currentLocation.coordinate.longitude), image: ecoImage, color: UIColor.systemGreen)
}
}
Here is the class that must create a custom annotation for the map
class ImageAnnotation : NSObject, MKAnnotation {
var coordinate: CLLocationCoordinate2D
var imageEco: UIImage?
var color: UIColor?
var imageView: UIImageView!
init(coordinate: CLLocationCoordinate2D, image: UIImage, color: UIColor) {
self.coordinate = coordinate
imageEco = image
self.color = color
imageView.image = image
imageView.frame = CGRect(x: 0, y: 0, width: 20, height: 20)
self.imageView = UIImageView(frame: CGRect(x: 0, y: 0, width: 20, height: 20))
imageView.addSubview(self.imageView)
self.imageView.layer.cornerRadius = 25
self.imageView.layer.masksToBounds = true
}
}
Here is the final result that must be implemented
You are saying imageView.image = image. But imageView is nil. So you crash. No big surprise.
Taking a larger perspective, it appears that you have failed to appreciate the difference between an annotation and an annotation view. An annotation is just a message carrier: it can say what the coordinate is and perhaps what image should be displayed, but that's all. It is the job of your map view delegate to create the corresponding annotation view on demand, and that is where you are dealing with a view and can arrange for it to display your circular image.
Is there a way that I can use the Vision framework to scan an existing image from the user's photo library? As in, not taking a new picture using the camera, but just choosing an image that the user already has?
Yes, you can. Adding on to #Zulqarnayn's answer, here's a working example to detect and draw a bounding box on rectangles.
1. Set up the image view where the image will be displayed
#IBOutlet weak var imageView: UIImageView!
#IBAction func pickImage(_ sender: Any) {
let picker = UIImagePickerController()
picker.delegate = self
self.present(picker, animated: true)
}
override func viewDidLoad() {
super.viewDidLoad()
imageView.layer.borderWidth = 4
imageView.layer.borderColor = UIColor.blue.cgColor
imageView.contentMode = .scaleAspectFill
imageView.backgroundColor = UIColor.green.withAlphaComponent(0.3)
imageView.layer.masksToBounds = false /// allow image to overflow, for testing purposes
}
2. Get the image from the image picker
extension ViewController: UIImagePickerControllerDelegate, UINavigationControllerDelegate {
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
guard let image = info[.originalImage] as? UIImage else { return }
/// set the imageView's image
imageView.image = image
/// start the request & request handler
detectCard()
/// dismiss the picker
dismiss(animated: true)
}
}
3. Start the vision request
func detectCard() {
guard let cgImage = imageView.image?.cgImage else { return }
/// perform on background thread, so the main screen is not frozen
DispatchQueue.global(qos: .userInitiated).async {
let request = VNDetectRectanglesRequest { request, error in
/// this function will be called when the Vision request finishes
self.handleDetectedRectangle(request: request, error: error)
}
request.minimumAspectRatio = 0.0
request.maximumAspectRatio = 1.0
request.maximumObservations = 1 /// only look for 1 rectangle
let imageRequestHandler = VNImageRequestHandler(cgImage: cgImage, orientation: .up)
do {
try imageRequestHandler.perform([request])
} catch let error {
print("Error: \(error)")
}
}
}
4. Get the result from the Vision request
func handleDetectedRectangle(request: VNRequest?, error: Error?) {
if let results = request?.results {
if let observation = results.first as? VNRectangleObservation {
/// get back to the main thread
DispatchQueue.main.async {
guard let image = self.imageView.image else { return }
let convertedRect = self.getConvertedRect(
boundingBox: observation.boundingBox,
inImage: image.size,
containedIn: self.imageView.bounds.size
)
self.drawBoundingBox(rect: convertedRect)
}
}
}
}
5. Convert observation.boundingBox to the UIKit coordinates of the image view, then draw a border around the detected rectangle
I explain this more in detail in this answer.
func getConvertedRect(boundingBox: CGRect, inImage imageSize: CGSize, containedIn containerSize: CGSize) -> CGRect {
let rectOfImage: CGRect
let imageAspect = imageSize.width / imageSize.height
let containerAspect = containerSize.width / containerSize.height
if imageAspect > containerAspect { /// image extends left and right
let newImageWidth = containerSize.height * imageAspect /// the width of the overflowing image
let newX = -(newImageWidth - containerSize.width) / 2
rectOfImage = CGRect(x: newX, y: 0, width: newImageWidth, height: containerSize.height)
} else { /// image extends top and bottom
let newImageHeight = containerSize.width * (1 / imageAspect) /// the width of the overflowing image
let newY = -(newImageHeight - containerSize.height) / 2
rectOfImage = CGRect(x: 0, y: newY, width: containerSize.width, height: newImageHeight)
}
let newOriginBoundingBox = CGRect(
x: boundingBox.origin.x,
y: 1 - boundingBox.origin.y - boundingBox.height,
width: boundingBox.width,
height: boundingBox.height
)
var convertedRect = VNImageRectForNormalizedRect(newOriginBoundingBox, Int(rectOfImage.width), Int(rectOfImage.height))
/// add the margins
convertedRect.origin.x += rectOfImage.origin.x
convertedRect.origin.y += rectOfImage.origin.y
return convertedRect
}
/// draw an orange frame around the detected rectangle, on top of the image view
func drawBoundingBox(rect: CGRect) {
let uiView = UIView(frame: rect)
imageView.addSubview(uiView)
uiView.backgroundColor = UIColor.clear
uiView.layer.borderColor = UIColor.orange.cgColor
uiView.layer.borderWidth = 3
}
Result | Demo repo
Input image
Result
Yes, you can. First, take an instance of UIImagePickerController & present it.
let picker = UIImagePickerController()
picker.delegate = self
picker.sourceType = .photoLibrary
present(picker, animated: true, completion: nil)
Then implement the delegate method take the desired image
extension YourViewController: UIImagePickerControllerDelegate {
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
if let pickedImage = info[.originalImage] as? UIImage {
## here start your request & request handler
}
picker.dismiss(animated: true, completion: nil)
}
}
I have a simple app that contains a button, UIImageView, and a label. Once you click on the button, you will be able to take a photo using the camera. Then the model has to predict what is the object in the photo, and finally the label has to display the output (the predicted object).
Everything is working fine and there are no errors, but after I take a picture, the label is not being changed, the model is not returning anything, why is that ?
NOTE: The model is working fine and it has been tested using another app, but I think I am missing something in this code.
Here is my code:
import UIKit
import CoreML
class secondViewController: UIViewController, UINavigationControllerDelegate {
#IBOutlet weak var imageView: UIImageView!
#IBOutlet weak var classifier: UILabel!
var model: VGG16!
let cameraPicker = UIImagePickerController()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func viewWillAppear(_ animated: Bool) {
model = VGG16()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#IBAction func camera(_ sender: Any) {
if !UIImagePickerController.isSourceTypeAvailable(.camera) {
return
}
cameraPicker.delegate = self
cameraPicker.sourceType = .camera
cameraPicker.allowsEditing = false
present(cameraPicker, animated: true)
}
}
extension secondViewController: UIImagePickerControllerDelegate {
func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
dismiss(animated: true, completion: nil)
}
// private func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
private func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey: Any]) {
picker.dismiss(animated: true, completion: nil)
let image = info[UIImagePickerController.InfoKey.originalImage]! as! UIImage
picker.dismiss(animated: true)
classifier.text = "Analyzing Image..."
UIGraphicsBeginImageContextWithOptions(CGSize(width: 299, height: 299), true, 2.0)
image.draw(in: CGRect(x: 0, y: 0, width: 299, height: 299))
let newImage = UIGraphicsGetImageFromCurrentImageContext()!
UIGraphicsEndImageContext()
let attrs = [kCVPixelBufferCGImageCompatibilityKey: kCFBooleanTrue, kCVPixelBufferCGBitmapContextCompatibilityKey: kCFBooleanTrue] as CFDictionary
var pixelBuffer : CVPixelBuffer?
let status = CVPixelBufferCreate(kCFAllocatorDefault, Int(newImage.size.width), Int(newImage.size.height), kCVPixelFormatType_32ARGB, attrs, &pixelBuffer)
guard (status == kCVReturnSuccess) else {
return
}
CVPixelBufferLockBaseAddress(pixelBuffer!, CVPixelBufferLockFlags(rawValue: 0))
let pixelData = CVPixelBufferGetBaseAddress(pixelBuffer!)
let rgbColorSpace = CGColorSpaceCreateDeviceRGB()
let context = CGContext(data: pixelData, width: Int(newImage.size.width), height: Int(newImage.size.height), bitsPerComponent: 8, bytesPerRow: CVPixelBufferGetBytesPerRow(pixelBuffer!), space: rgbColorSpace, bitmapInfo: CGImageAlphaInfo.noneSkipFirst.rawValue) //3
context?.translateBy(x: 0, y: newImage.size.height)
context?.scaleBy(x: 1.0, y: -1.0)
UIGraphicsPushContext(context!)
newImage.draw(in: CGRect(x: 0, y: 0, width: newImage.size.width, height: newImage.size.height))
UIGraphicsPopContext()
CVPixelBufferUnlockBaseAddress(pixelBuffer!, CVPixelBufferLockFlags(rawValue: 0))
imageView.image = newImage
// Core ML
guard let prediction = try? model.prediction(image: pixelBuffer!) else {
return
}
classifier.text = "I think this is a \(prediction.classLabel)."
}
}
You need to hold a strong reference to
let cameraPicker = UIImagePickerController()
override func viewDidLoad() {
by making it an instance variable for the delegate methods to be called
Do consider this as a question from someone who is not so good at swift..:).I have a button on the click of which the imagepicker is opened and I am able to select the images. In the didFinishPickingMediaWithInfo I'm adding the image to array like so...
var imageArray = [UIImage]()
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
if let image = info[UIImagePickerControllerOriginalImage] as? UIImage {
UIImageWriteToSavedPhotosAlbum(image, self, #selector(image(_:didFinishSavingWithError:contextInfo:)), nil)
imageArray.append(image)
for i in 0..<imageArray.count {
imageView.image = imageArray[i]
imageView.contentMode = .scaleAspectFit
let xPosition = self.view.frame.width * CGFloat(i)
imageView.frame = CGRect(x: xPosition, y: 0, width: self.imageScrollView.frame.width, height: self.imageScrollView.frame.height)
imageScrollView.contentSize.width = imageScrollView.frame.width * (CGFloat(i + 1))
imageScrollView.addSubview(imageView)
}
}
self.dismiss(animated: true, completion: nil)
}
I'm also having these functions:
func saveImage(image: UIImage, path: String) -> Bool {
let jpgImageData = UIImageJPEGRepresentation(image, 1.0)
do {
try jpgImageData?.write(to: URL(fileURLWithPath: path), options: .atomic)
} catch {
print(error)
}
return (jpgImageData != nil)
}
func getDocumentsURL() -> NSURL {
let documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
return documentsURL as NSURL
}
func fileInDocumentsDirectory(filename: String) -> String {
let fileURL = getDocumentsURL().appendingPathComponent(filename)
return fileURL!.path
}
But my issue is this..I just don't want to show just one image that is picked from the gallery. I want to pick multiple images from the gallery(one at a time), store them in an array and then display them all in a horizontal scrolling format. For this purpose, I'm setting a scrollview to take the images(as given in didFinishPickingMediaWithInfo)
Maybe I have to read the image also. But how that can be done I'm not able to figure out...Please help!
Please see this loop which i have corrected
You are only creating one UIImageView and adding to the scrollview.
Please initialize the UIImageView every time
for i in 0..<imageArray.count {
var imageView = UIImageView() //*** Add this line to your code
imageView.image = imageArray[i]
imageView.contentMode = .scaleAspectFit
let xPosition = self.view.frame.width * CGFloat(i)
imageView.frame = CGRect(x: xPosition, y: 0, width: self.imageScrollView.frame.width, height: self.imageScrollView.frame.height)
imageScrollView.contentSize.width = imageScrollView.frame.width * (CGFloat(i + 1))
imageScrollView.addSubview(imageView)
}
When ever you update your scrollview with newImages dont forget to remove the old ones.
Use this to save image
var imageArr:[UIImage] = []
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
let chosenImage = info[UIImagePickerControllerOriginalImage] as! UIImage
UIImageWriteToSavedPhotosAlbum(chosenImage, self, #selector(image(_:didFinishSavingWithError:contextInfo:)), nil)
imageArr.append(chosenImage)
for i in 0..<imageArray.count
{
imageView.image = imageArray[i]
imageView.contentMode = .scaleAspectFit
let xPosition = self.view.frame.width * CGFloat(i)
imageView.frame = CGRect(x: xPosition, y: 0, width: self.imageScrollView.frame.width, height: self.imageScrollView.frame.height)
imageScrollView.contentSize.width = imageScrollView.frame.width * (CGFloat(i + 1))
imageScrollView.addSubview(imageView)
}
}
I am pretty new to Swift.
I intend to draw a rectangle and capture the image in the rectangular overlay.
I drew a transparent image over the camera.
let imagePicker = UIImagePickerController()
imagePicker.delegate = self
imagePicker.sourceType = UIImagePickerControllerSourceType.Camera
imagePicker.mediaTypes = [kUTTypeImage as String]
imagePicker.allowsEditing = true
var overlayedImageView: UIImageView = UIImageView(image: UIImage(named: "transparent.png"))
var cgRect: CGRect = CGRect(x: 200, y: 50, width: 100, height: 400)
overlayedImageView.frame = cgRect
imagePicker.cameraOverlayView = overlayedImageView
self.presentViewController(imagePicker, animated: true,
completion: nil)
This is what i do after i capture the image
func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : AnyObject]) {
let mediaType = info[UIImagePickerControllerMediaType] as! String
self.dismissViewControllerAnimated(true, completion: nil)
if mediaType == (kUTTypeImage as String) {
let image = info[UIImagePickerControllerOriginalImage]
as! UIImage
imageView.image = cropToBoundsNew(image)
if (newMedia == true) {
UIImageWriteToSavedPhotosAlbum(image, self,
"image:didFinishSavingWithError:contextInfo:", nil)
} else if mediaType == (kUTTypeMovie as String) {
// Code to support video here
}
}
}
My Problem is the quality of the image diminishes
func cropToBoundsNew(image: UIImage) -> UIImage {
let contextImage: UIImage = UIImage(CGImage: image.CGImage!)
let contextSize: CGSize = contextImage.size
let rect: CGRect = CGRectMake(200, 50, 100, 400)
let imageRef: CGImageRef = CGImageCreateWithImageInRect(contextImage.CGImage, rect)!
let image: UIImage = UIImage(CGImage: imageRef, scale: image.scale, orientation: image.imageOrientation)
return image
}