I tried to look up the answer on the Internet and did not find it, maybe I typed my query wrong on the Internet.
Can you tell me how to crop a 3:4 photo? I can't find the function to crop it. Please share?
You can use this function to crop your image in any AspectRatio (e.g 3:4). You have to pass your Image and desired AspectRatio as a parameter to the function and it will return you the Cropped Image.
func crop(image: UIImage, to aspectRatio: CGFloat) -> UIImage {
let originalAspectRatio = image.size.height/image.size.width
var newImagesize = image.size
if originalAspectRatio > aspectRatio {
newImagesize.height = image.size.width * aspectRatio
} else if originalAspectRatio < aspectRatio {
newImagesize.width = image.size.height / aspectRatio
} else {
return image
}
let center = CGPoint(x: image.size.width/2, y: image.size.height/2)
let origin = CGPoint(x: center.x - newImagesize.width/2, y: center.y - newImagesize.height/2)
let cgCroppedImage = image.cgImage!.cropping(to: CGRect(origin: origin, size: CGSize(width: newImagesize.width, height: newImagesize.height)))!
let croppedImage = UIImage(cgImage: cgCroppedImage, scale: image.scale, orientation: image.imageOrientation)
return croppedImage
}
Usage:
let croppedImage = crop(image: "ImageName", to: 3/4)
Use the following function. For more details read this.
func cropImage(_ inputImage: UIImage, toRect cropRect: CGRect, viewWidth: CGFloat, viewHeight: CGFloat) -> UIImage?
{
let imageViewScale = max(inputImage.size.width / viewWidth,
inputImage.size.height / viewHeight)
// Scale cropRect to handle images larger than shown-on-screen size
let cropZone = CGRect(x:cropRect.origin.x * imageViewScale,
y:cropRect.origin.y * imageViewScale,
width:cropRect.size.width * imageViewScale,
height:cropRect.size.height * imageViewScale)
// Perform cropping in Core Graphics
guard let cutImageRef: CGImage = inputImage.cgImage?.cropping(to:cropZone)
else {
return nil
}
// Return image to UIImage
let croppedImage: UIImage = UIImage(cgImage: cutImageRef)
return croppedImage
}
Related
I have large images uploaded by users in Swift and I need to resize them all to 100x100px to create thumbnails to store in my server. So far I have found that this resizes an image given a CGSize:
func resizedImage(image: UIImage, size: CGSize) -> UIImage? {
let renderer = UIGraphicsImageRenderer(size: size)
return renderer.image { (context) in
image.draw(in: CGRect(origin: .zero, size: size))
}
}
Is there any way to create a CGSize knowing that my target size is strictly 100x100px?
Got this to work:
extension UIImage {
func resizedImage(pixelSize: (width: Int, height: Int)) -> UIImage? {
var size = CGSize(width: CGFloat(pixelSize.width) / UIScreen.main.scale, height: CGFloat(pixelSize.height) / UIScreen.main.scale)
let rect = AVMakeRect(aspectRatio: self.size, insideRect: CGRect(x:0, y:0, width: size.width, height: size.height))
let renderer = UIGraphicsImageRenderer(size: size)
return renderer.image { (context) in
self.draw(in: rect)
}
}
}
You should initialize your render based on the user device scale and multiply its width and height instead of dividing it:
extension UIImage {
func aspectFitScaled(to size: CGSize) -> UIImage {
let format = imageRendererFormat
format.opaque = false
format.scale = UIScreen.main.scale
let isLandscape = self.size.width > self.size.height
let ratio = isLandscape ? size.width / self.size.width : size.height / self.size.height
let drawSize = self.size.scaled(by: ratio)
let x = (size.width - drawSize.width) / 2
let y = (size.height - drawSize.height) / 2
let origin = CGPoint(x: x, y: y)
return UIGraphicsImageRenderer(size: size, format: format).image { _ in
draw(in: CGRect(origin: origin, size: drawSize))
}
}
}
usage:
class ViewController: UIViewController {
// imageView frame is 200 x 200
#IBOutlet weak var imageView: UIImageView!
override func viewDidLoad() {
super.viewDidLoad()
// original image size is (719.0, 808.0)
let image = UIImage(data: try! Data(contentsOf: URL(string: "https://i.stack.imgur.com/Xs4RX.jpg")!))!
imageView.backgroundColor = .gray
let ivImage = image.aspectFitScaled(to: imageView.frame.size)
imageView.image = ivImage
print("ivImage.size", ivImage.size) // (200.0, 200.0)
print("ivImage.scale", ivImage.scale) // screen scale 3.0 iPhone 8 Plus
// lets check the real image dimension
let data = ivImage.jpegData(compressionQuality: 1)!
let savedSize = UIImage(data: data)!.size
print("savedSize", savedSize) // savedSize (600.0, 600.0)
}
}
I'm looking for a tutorial to tell me how to create a frame to crop the photo, as the picture below
thanks
As a first step please look into implementing a UIView that resizes using the corners/handles. This post should help
Once we have a resizable UIView, then using UIView.frame's origin and size to crop the image, like so:
extension UIImage {
func crop(size: CGSize, offset: CGPoint, scale: CGFloat = 1.0) -> UIImage? {
let rect = CGRect(x: offset.x * scale, y: offset.y * scale, width: size.width * scale, height: size.height * scale)
if let cropped = self.cgImage?.cropping(to: rect) {
return UIImage(cgImage: cropped)
}
return nil
}
}
let croppedImage = image.crop(size: resizableView.frame.size, offset: resizableView.frame.origin)
I have an image in a UIImageView:
imageView.contentMode = .scaleAspectFit
imageView.backgroundColor = .red
because of .scaleAspectFit the image view has some red borders and thats OK:
User can added some UIView like label or images over the imageView.
In final step I used the following code to save edited image and user can share it or save it to photo library:
private func generateImage() -> UIImage? {
var finalImage: UIImage?
UIGraphicsBeginImageContextWithOptions(CGSize(width: imageView.frame.size.width, height: imageView.frame.size.height), true, 0)
imageView.drawHierarchy(in: CGRect(x: 0, y: 0, width: imageView.frame.size.width, height: imageView.frame.size.height), afterScreenUpdates: true)
finalImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return image
}
The problem is that the finalImage still has the red borders from imageView.
You can get CGRect of the UIImage displayed in the UIImageView in AspectFit content mode. Please create extension of UIImageView like this,
extension UIImageView {
var contentClippingRect: CGRect {
guard let image = image else { return bounds }
guard contentMode == .scaleAspectFit else { return bounds }
guard image.size.width > 0 && image.size.height > 0 else { return bounds }
let scale: CGFloat
if image.size.width > image.size.height {
scale = bounds.width / image.size.width
} else {
scale = bounds.height / image.size.height
}
let size = CGSize(width: image.size.width * scale, height: image.size.height * scale)
let x = (bounds.width - size.width) / 2.0
let y = (bounds.height - size.height) / 2.0
return CGRect(x: x, y: y, width: size.width, height: size.height)
}
}
You can now use imageView.contentClippingRect to read how read the position and size of the image inside.
You have to do minor changes in your method, call your function with appropriate bounds as contentClippingRect.
Let me know in case of any queries.
UPDATE
Please try this UIImageView+Extension, this might help you. It is in Objective-C code, convert it in Swift.
You can try this as well,
let image = #imageLiteral(resourceName: "Cat03")
let x: CGRect = AVMakeRect(aspectRatio: image.size, insideRect: imageView1.frame)
print(x)
Above code gives you size perfectly.
I am trying to resize a NSImage implementing a code that I got from this website https://gist.github.com/eiskalteschatten/dac3190fce5d38fdd3c944b45a4ca469, but it's not working.
Here is the code:
static func redimensionaNSImage(imagem: NSImage, tamanho: NSSize) -> NSImage {
var imagemRect: CGRect = CGRect(x: 0, y: 0, width: imagem.size.width, height: imagem.size.height)
let imagemRef = imagem.cgImage(forProposedRect: &imagemRect, context: nil, hints: nil)
return NSImage(cgImage: imagemRef!, size: tamanho)
}
I forgot to calculate the ratio. Now it's working fine.
static func redimensionaNSImage(imagem: NSImage, tamanho: NSSize) -> NSImage {
var ratio:Float = 0.0
let imageWidth = Float(imagem.size.width)
let imageHeight = Float(imagem.size.height)
let maxWidth = Float(tamanho.width)
let maxHeight = Float(tamanho.height)
// Get ratio (landscape or portrait)
if (imageWidth > imageHeight) {
// Landscape
ratio = maxWidth / imageWidth;
}
else {
// Portrait
ratio = maxHeight / imageHeight;
}
// Calculate new size based on the ratio
let newWidth = imageWidth * ratio
let newHeight = imageHeight * ratio
// Create a new NSSize object with the newly calculated size
let newSize:NSSize = NSSize(width: Int(newWidth), height: Int(newHeight))
// Cast the NSImage to a CGImage
var imageRect:CGRect = CGRect(x: 0, y: 0, width: imagem.size.width, height: imagem.size.height)
let imageRef = imagem.cgImage(forProposedRect: &imageRect, context: nil, hints: nil)
// Create NSImage from the CGImage using the new size
let imageWithNewSize = NSImage(cgImage: imageRef!, size: newSize)
// Return the new image
return imageWithNewSize
}
I've taken an image and converted it to the jpeg format as such
let jpgImage = UIImageJPEGRepresentation(image1, 0.5)
Next I want to upload this image to Parse as a object part of a PFUser. When ever I try this I get the error
[Error]: The object is too large -- should be less than 128 kB
I don't know how to fix this error and just sign up the user. Thanks for any help or advice!
Objects are limited to 128kb as the error states, if your image is larger than that as it is you can choose to shrink it by using the function below.
func ResizeImage(image: UIImage, targetSize: CGSize) -> UIImage {
let size = image.size
let widthRatio = targetSize.width / image.size.width
let heightRatio = targetSize.height / image.size.height
// Figure out what our orientation is, and use that to form the rectangle
var newSize: CGSize
if(widthRatio > heightRatio) {
newSize = CGSizeMake(size.width * heightRatio, size.height * heightRatio)
} else {
newSize = CGSizeMake(size.width * widthRatio, size.height * widthRatio)
}
// This is the rect that we've calculated out and this is what is actually used below
let rect = CGRectMake(0, 0, newSize.width, newSize.height)
// Actually do the resizing to the rect using the ImageContext stuff
UIGraphicsBeginImageContextWithOptions(newSize, false, 1.0)
image.drawInRect(rect)
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return newImage
}
Use of the above function, you can resize your image as dynamics
dimension.Here as above code resize image of 200*200. By calling the
below function.
self.ResizeImage(UIImage(named: "yourImageName")!, targetSize: CGSizeMake(200.0, 200.0))
Source code from here.
So start by checking the image size by:
let sizeOfImage = image?.size
if let image = image {
let sizeOfImage = image.size
// Check the size here and resize if needed
}