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)
Related
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
}
I'm building an augmented reality app and would like to show preview images of the available DAE files.
Is it possible to use Swift to extract image data from a DAE file and to load that into an UIImage?
Out of the box there is no function to call that will pull a screen shot from a .dae file. Thats not to say that there isn't a way to do this on device.
To understand what you are asking lets consider the different components.
The .dae file is loaded using an ARSCNView, which is a reader for .dae files. The ARSCNView is traditionally added as a subview to your ViewController. In this instance you would need the viewer to render the 3D file offscreen so you need to create an ARSCNView but do not add it as a subview of the VC (i would add it during the initial setup to make sure it all loads, but then comment that line out)
Once you have your 3D loaded into your ARSCNView, use the below function to rip the context of the view into a JPG image
let viewSnapshot = takeSnapshotOfView(view: yourARSCNView)
and to rip the context and resize the JPG:
import UIKit
import CoreGraphics
func takeSnapshotOfView(view:UIView) -> UIImage? {
UIGraphicsBeginImageContext(CGSize(width: view.frame.size.width, height: view.frame.size.height))
view.drawHierarchy(in: CGRect(x: 0.0, y: 0.0, width: view.frame.size.width, height: view.frame.size.height), afterScreenUpdates: true)
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return image?.resize(CGRect(x: 0, y: 0, width: 300, height: (image?.size.height)! / 300 * (image?.size.width)!)) // resize image before returning
}
extension UIImage {
func resize(_ toSize: CGRect) -> UIImage {
let size = self.size
let widthRatio = toSize.width / self.size.width
let heightRatio = toSize.height / self.size.height
var newSize: CGSize
if widthRatio > heightRatio {
newSize = CGSize(width: size.width * heightRatio, height: size.height * heightRatio)
} else {
newSize = CGSize(width: size.width * widthRatio, height: size.height * widthRatio)
}
let rect = CGRect(x: 0, y: 0, width: newSize.width, height: newSize.height)
UIGraphicsBeginImageContextWithOptions(newSize, false, 1.0)
self.draw(in: rect)
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return newImage!
}
}
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 crop this image, which is a SKSpriteNode:
I am trying to crop this image from the top, so that I maintain the bottom semi circle of this shape. For instance, it'd be cropped to this:
So I use these two methods to accomplish this task:
func recalculateScore() {
currentScore -= decreaseRate
let image = UIImage(cgImage: (vial.texture?.cgImage())!)
vial.texture = SKTexture(image: cropBottomImage(image: image))
}
func cropBottomImage(image: UIImage) -> UIImage {
let height = CGFloat(image.size.height / 3)
let rect = CGRect(x: 0, y: image.size.height - height, width: image.size.width, height: height)
return cropImage(image: image, toRect: rect)
}
func cropImage(image:UIImage, toRect rect:CGRect) -> UIImage {
let imageRef:CGImage = image.cgImage!.cropping(to: rect)!
let croppedImage:UIImage = UIImage(cgImage:imageRef)
return croppedImage
}
However, this leads to this result:
It is as if it was being compressed. I think my issue might be in this line:
let rect = CGRect(x: 0, y: image.size.height - height, width: image.size.width, height: height)
Does the CGRect coordinate of (0,0) lie within the top most left corner? I am a bit confused on what the x and y parameters for the CGRect mean?
Resize your sprite, what is happening is the cropped texture is stretching to fill the sprite, and since you only crop vertically, it will only stretch vertically
func recalculateScore() {
currentScore -= decreaseRate
let image = UIImage(cgImage: (vial.texture?.cgImage())!)
vial.texture = SKTexture(image: cropBottomImage(image: image))
vial.size = vial.texture.size
}
Is there an easy way to rotate a NSImage in a Mac OSX app? Or just set the orientation from portrait to landscape using Swift?
I am playing around with CATransform3DMakeAffineTransform but I can't get it to work.
CATransform3DMakeAffineTransform(CGAffineTransformMakeRotation(CGFloat(M_PI) * 90/180))
It's the first time for me to work with transformations. So please be patient with me :) Maybe I'm working on a wrong approach...
Can anybody help me please?
Thanks!
public extension NSImage {
public func imageRotatedByDegreess(degrees:CGFloat) -> NSImage {
var imageBounds = NSZeroRect ; imageBounds.size = self.size
let pathBounds = NSBezierPath(rect: imageBounds)
var transform = NSAffineTransform()
transform.rotateByDegrees(degrees)
pathBounds.transformUsingAffineTransform(transform)
let rotatedBounds:NSRect = NSMakeRect(NSZeroPoint.x, NSZeroPoint.y, pathBounds.bounds.size.width, pathBounds.bounds.size.height )
let rotatedImage = NSImage(size: rotatedBounds.size)
//Center the image within the rotated bounds
imageBounds.origin.x = NSMidX(rotatedBounds) - (NSWidth(imageBounds) / 2)
imageBounds.origin.y = NSMidY(rotatedBounds) - (NSHeight(imageBounds) / 2)
// Start a new transform
transform = NSAffineTransform()
// Move coordinate system to the center (since we want to rotate around the center)
transform.translateXBy(+(NSWidth(rotatedBounds) / 2 ), yBy: +(NSHeight(rotatedBounds) / 2))
transform.rotateByDegrees(degrees)
// Move the coordinate system bak to normal
transform.translateXBy(-(NSWidth(rotatedBounds) / 2 ), yBy: -(NSHeight(rotatedBounds) / 2))
// Draw the original image, rotated, into the new image
rotatedImage.lockFocus()
transform.concat()
self.drawInRect(imageBounds, fromRect: NSZeroRect, operation: NSCompositingOperation.CompositeCopy, fraction: 1.0)
rotatedImage.unlockFocus()
return rotatedImage
}
var image = NSImage(named:"test.png")!.imageRotatedByDegreess(CGFloat(90)) //use only this values 90, 180, or 270
}
Updated for Swift 3:
public extension NSImage {
public func imageRotatedByDegreess(degrees:CGFloat) -> NSImage {
var imageBounds = NSZeroRect ; imageBounds.size = self.size
let pathBounds = NSBezierPath(rect: imageBounds)
var transform = NSAffineTransform()
transform.rotate(byDegrees: degrees)
pathBounds.transform(using: transform as AffineTransform)
let rotatedBounds:NSRect = NSMakeRect(NSZeroPoint.x, NSZeroPoint.y, pathBounds.bounds.size.width, pathBounds.bounds.size.height )
let rotatedImage = NSImage(size: rotatedBounds.size)
//Center the image within the rotated bounds
imageBounds.origin.x = NSMidX(rotatedBounds) - (NSWidth(imageBounds) / 2)
imageBounds.origin.y = NSMidY(rotatedBounds) - (NSHeight(imageBounds) / 2)
// Start a new transform
transform = NSAffineTransform()
// Move coordinate system to the center (since we want to rotate around the center)
transform.translateX(by: +(NSWidth(rotatedBounds) / 2 ), yBy: +(NSHeight(rotatedBounds) / 2))
transform.rotate(byDegrees: degrees)
// Move the coordinate system bak to normal
transform.translateX(by: -(NSWidth(rotatedBounds) / 2 ), yBy: -(NSHeight(rotatedBounds) / 2))
// Draw the original image, rotated, into the new image
rotatedImage.lockFocus()
transform.concat()
self.draw(in: imageBounds, from: NSZeroRect, operation: NSCompositingOperation.copy, fraction: 1.0)
rotatedImage.unlockFocus()
return rotatedImage
}
}
class SomeClass: NSViewController {
var image = NSImage(named:"test.png")!.imageRotatedByDegreess(degrees: CGFloat(90)) //use only this values 90, 180, or 270
}
Thank for this solution, however it did not worked perfectly for me.
As you may have noticed that pathBounds is not used anywhere. In my opinion is has to be used like so:
let rotatedBounds:NSRect = NSMakeRect(NSZeroPoint.x, NSZeroPoint.y , pathBounds.bounds.size.width, pathBounds.bounds.size.height )
Otherwise the image will be rotated but cropped to a square bounds.
Letting IKImageView do the heavy lifting:
import Quartz
extension NSImage {
func imageRotated(by degrees: CGFloat) -> NSImage {
let imageRotator = IKImageView()
var imageRect = CGRect(x: 0, y: 0, width: self.size.width, height: self.size.height)
let cgImage = self.cgImage(forProposedRect: &imageRect, context: nil, hints: nil)
imageRotator.setImage(cgImage, imageProperties: [:])
imageRotator.rotationAngle = CGFloat(-(degrees / 180) * CGFloat(M_PI))
let rotatedCGImage = imageRotator.image().takeUnretainedValue()
return NSImage(cgImage: rotatedCGImage, size: NSSize.zero)
}
}
Here's a simple Swift (4+) solution to drawing an image that is rotated around the center:
extension NSImage {
/// Rotates the image by the specified degrees around the center.
/// Note that if the angle is not a multiple of 90°, parts of the rotated image may be drawn outside the image bounds.
func rotated(by angle: CGFloat) -> NSImage {
let img = NSImage(size: self.size, flipped: false, drawingHandler: { (rect) -> Bool in
let (width, height) = (rect.size.width, rect.size.height)
let transform = NSAffineTransform()
transform.translateX(by: width / 2, yBy: height / 2)
transform.rotate(byDegrees: angle)
transform.translateX(by: -width / 2, yBy: -height / 2)
transform.concat()
self.draw(in: rect)
return true
})
img.isTemplate = self.isTemplate // preserve the underlying image's template setting
return img
}
}
This one works also for non-square images, Swift 5.
extension NSImage {
func rotated(by degrees : CGFloat) -> NSImage {
var imageBounds = NSRect(x: 0, y: 0, width: size.width, height: size.height)
let rotatedSize = AffineTransform(rotationByDegrees: degrees).transform(size)
let newSize = CGSize(width: abs(rotatedSize.width), height: abs(rotatedSize.height))
let rotatedImage = NSImage(size: newSize)
imageBounds.origin = CGPoint(x: newSize.width / 2 - imageBounds.width / 2, y: newSize.height / 2 - imageBounds.height / 2)
let otherTransform = NSAffineTransform()
otherTransform.translateX(by: newSize.width / 2, yBy: newSize.height / 2)
otherTransform.rotate(byDegrees: degrees)
otherTransform.translateX(by: -newSize.width / 2, yBy: -newSize.height / 2)
rotatedImage.lockFocus()
otherTransform.concat()
draw(in: imageBounds, from: CGRect.zero, operation: NSCompositingOperation.copy, fraction: 1.0)
rotatedImage.unlockFocus()
return rotatedImage
}
}
Building on #FrankByte.com's code, this version should extend correctly in both x and y on any image and any rotation.
extension NSImage {
func rotated(by degrees: CGFloat) -> NSImage {
let sinDegrees = abs(sin(degrees * CGFloat.pi / 180.0))
let cosDegrees = abs(cos(degrees * CGFloat.pi / 180.0))
let newSize = CGSize(width: size.height * sinDegrees + size.width * cosDegrees,
height: size.width * sinDegrees + size.height * cosDegrees)
let imageBounds = NSRect(x: (newSize.width - size.width) / 2,
y: (newSize.height - size.height) / 2,
width: size.width, height: size.height)
let otherTransform = NSAffineTransform()
otherTransform.translateX(by: newSize.width / 2, yBy: newSize.height / 2)
otherTransform.rotate(byDegrees: degrees)
otherTransform.translateX(by: -newSize.width / 2, yBy: -newSize.height / 2)
let rotatedImage = NSImage(size: newSize)
rotatedImage.lockFocus()
otherTransform.concat()
draw(in: imageBounds, from: CGRect.zero, operation: NSCompositingOperation.copy, fraction: 1.0)
rotatedImage.unlockFocus()
return rotatedImage
}
}