I am cropping a UIImage by using UIGraphicsGetCurrentContext and then saving it to cache. I then show that UIImage as the image of one of my tab bar items. This works, however, the scale factor of the image is an issue. If I use UIGraphicsBeginImageContextWithOptions with the scale set to zero, this correctly crops it using the scale factor of the screen. However, when I set the UITabBarItem image, it seems to ignore the fact that the image should be scaled.
My code for scaling:
extension UIImage {
func scaledImage(withSize size: CGSize, withBorder: Bool) -> UIImage {
let imageView = UIImageView(image: self)
imageView.frame = CGRect(x: 0, y: 0, width: size.width, height: size.height)
imageView.contentMode = .scaleAspectFit
let layer = imageView.layer
layer.masksToBounds = true
layer.cornerRadius = size.width/2
if withBorder {
layer.borderColor = Styles.Colours.blue.colour.cgColor
layer.borderWidth = 2
}
UIGraphicsBeginImageContextWithOptions(imageView.bounds.size, false, 1) // Notice I've set the scale factor to 1 here for now. If I set it to 0 the image is too large on the tab bar
defer { UIGraphicsEndImageContext() }
layer.render(in: UIGraphicsGetCurrentContext()!)
return UIGraphicsGetImageFromCurrentImageContext()!
}
}
Used like this:
let defaultImage = image?.scaledImage(withSize: CGSize(width: 25, height: 25), withBorder: false)
Then I set the tab bar item like this:
self.tabBar.items?.last?.image = defaultImage.withRenderingMode(.alwaysOriginal)
If I was to set a UIImage from my Assets, then it would take into account the scale factor. How do I fix this? Thanks!
Solved it by converting the UIImage to one that specifically defines the scale like this:
let scaledSelectedImage = UIImage(data: UIImagePNGRepresentation(image)!, scale: UIScreen.main.scale)
UIGraphicsBeginImageContextWithOptions(imageView.bounds.size, false, 1) is saying that you want the image context to be set at a scale of #1x. If you set it to 0 it uses the screen's native scale:
UIGraphicsBeginImageContextWithOptions(imageView.bounds.size, false, 0)
Related
Why does Xcode shows a image bigger then AS-IS?
http://users.telenet.be/thomazz/ScreenShot4.png
http://users.telenet.be/thomazz/ScreenShot3.png
Scenario:
I got an image.
I resize this UIImage.
I export the resized UIImage.
I comment out my resize code.
I import the resized image in Xcode.
problem 1: Xcode shows the image twice as big as normal.
problem 2: when I run my app with the exported-resized image, it is twice as big.
view screenshots.
This totally depends on your frame of your UIImageView and not its dimensions.
So if you have an 1024x1024 image and you place it in a 10x10 frame, it will render to 10x10 size and vice versa.
If you want it bigger, then make your UIImageView bigger
Edit: so it is a google maps icon
Set the resized image as marker icon ,i.e,
marker.icon = self.imageWithImage(image: UIImage(named: "imageName")!, scaledToSize: CGSize(width: 3.0, height: 3.0))
Add this function
func imageWithImage(image:UIImage, scaledToSize newSize:CGSize) -> UIImage{
UIGraphicsBeginImageContextWithOptions(newSize, false, 0.0);
image.drawInRect(CGRectMake(0, 0, newSize.width, newSize.height))
let newImage:UIImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return newImage
}
Dear Mohammad Bashir Sidani, I have this code.
And this code works. but it creates a new UIImage.
Then I use UIImagePNGRepresentation(resizedImage) to export the image.
I disable the code below to use the "programmatically-resized image".
this new resized image is blown up by Xcode... :(
extension UIImage {
func resizeImage(_ dimension: CGFloat, opaque: Bool, contentMode: UIViewContentMode = .scaleAspectFit) -> UIImage {
var width: CGFloat
var height: CGFloat
var newImage: UIImage
let size = self.size
let aspectRatio = size.width/size.height
switch contentMode {
case .scaleAspectFit:
if aspectRatio > 1 { // Landscape image
width = dimension
height = dimension / aspectRatio
} else { // Portrait image
height = dimension
width = dimension * aspectRatio
}
default:
fatalError("UIIMage.resizeToFit(): FATAL: Unimplemented ContentMode")
}
if #available(iOS 10.0, *) {
let renderFormat = UIGraphicsImageRendererFormat.default()
renderFormat.opaque = opaque
let renderer = UIGraphicsImageRenderer(size: CGSize(width: width, height: height), format: renderFormat)
newImage = renderer.image {
(context) in
self.draw(in: CGRect(x: 0, y: 0, width: width, height: height))
}
} else {
UIGraphicsBeginImageContextWithOptions(CGSize(width: width, height: height), opaque, 0)
self.draw(in: CGRect(x: 0, y: 0, width: width, height: height))
newImage = UIGraphicsGetImageFromCurrentImageContext()!
UIGraphicsEndImageContext()
}
return newImage
}
}
In order to understand my problem I will start with a short description of my goal:
In the center of my tab bar I deliberately use a usually too big image (a circle) which extends over the tab bar (the tab bar's background color is white) so it laps over the top border of the tab bar. Since all UITabBarItems' default color is a light gray (apparently it is neither UIColor.lightGray nor .darkGray) and I would like to change the color of this (and only this) UITabBarItem (or rather the image considering this is the only thing which can be seen of this UITabBarItem) to white I've used the following extension/function which works fine:
extension UIImage {
func tabBarImageWithCustomTint(tintColor: UIColor) -> UIImage {
UIGraphicsBeginImageContextWithOptions(self.size, false, self.scale)
let context: CGContext = UIGraphicsGetCurrentContext()!
context.translateBy(x: 0, y: self.size.height)
context.scaleBy(x: 1.0, y: -1.0)
context.setBlendMode(CGBlendMode(rawValue: 1)!)
let rect: CGRect = CGRect(x: 0, y: 0, width: self.size.width, height: self.size.height)
context.clip(to: rect, mask: self.cgImage!)
tintColor.setFill()
context.fill(rect)
var newImage: UIImage = UIGraphicsGetImageFromCurrentImageContext()!
UIGraphicsEndImageContext()
newImage = newImage.withRenderingMode(UIImageRenderingMode.alwaysOriginal)
return newImage
}
}
Link to question where I found this extension
As both the tint color of the image and the background color of the tab bar are white, I would now like to add a border of red color to the now white image. Luckily, I managed to find another question on stackoverflow which answered this question (although I must add that I am not entirely content with this extension because it leaves a very small space between the UIImage and the border):
extension UIImage {
func roundedImageWithBorder(width: CGFloat, color: UIColor) -> UIImage? {
let square = CGSize(width: min(size.width, size.height) + width * 2, height: min(size.width, size.height) + width * 2)
let imageView = UIImageView(frame: CGRect(origin: CGPoint(x: 0, y: 0), size: square))
imageView.contentMode = .center
imageView.image = self
imageView.layer.cornerRadius = square.width/2
imageView.layer.masksToBounds = true
imageView.layer.borderWidth = width
imageView.layer.borderColor = color.cgColor
UIGraphicsBeginImageContextWithOptions(imageView.bounds.size, false, scale)
guard let context = UIGraphicsGetCurrentContext() else { return nil }
imageView.layer.render(in: context)
let result = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return result
}
}
My problem now is if I use the function consecutively like this...:
let tabRecordButton = UIImage(named: "circle").tabBarImageWithCustomTint(tintColor: .white).roundedImageWithBorder(width: 1, color: .red)
..., the border is drawn but the UITabBarItem's tint color goes back to this default gray aforementioned (not even the border is red).
So my question: Is there a way I can do both, i.e. color the image white and the border red in my UITabBar?
You have to add this line result = result.withRenderingMode(UIImageRenderingMode.alwaysOriginal) in your second extension as well, if you omit this line then your image will take the tint from your tabBar, that is your original issue
replace your roundedImageWithBorder extension method implementation with this one
func roundedImageWithBorder(width: CGFloat, color: UIColor) -> UIImage? {
let square = CGSize(width: min(size.width, size.height) + width * 2, height: min(size.width, size.height) + width * 2)
let imageView = UIImageView(frame: CGRect(origin: CGPoint(x: 0, y: 0), size: square))
imageView.contentMode = .center
imageView.image = self
imageView.layer.cornerRadius = square.width/2
imageView.layer.masksToBounds = true
imageView.layer.borderWidth = width
imageView.layer.borderColor = color.cgColor
UIGraphicsBeginImageContextWithOptions(imageView.bounds.size, false, scale)
guard let context = UIGraphicsGetCurrentContext() else { return nil }
imageView.layer.render(in: context)
var result = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
result = result?.withRenderingMode(UIImageRenderingMode.alwaysOriginal)
return result
}
Testing
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
self.tabBarItem.selectedImage = UIImage(named: "icono-menu")?.tabBarImageWithCustomTint(tintColor: UIColor.magenta).roundedImageWithBorder(width: 1, color: UIColor.blue)
self.tabBarController?.tabBar.tintColor = UIColor.red //note that the tintColor of the tabBar is red
}
Result
I currently have in image in a nav bar but it's overlapping the edge:
Here is the code I use in viewDidLoad:
let logo = UIImage(named: "holy-grail-pub-logo-header-logo")
let imageView = UIImageView(image:logo)
imageView.contentMode = .ScaleAspectFit
self.navigationItem.titleView = imageView
I've tried setting the position manually using CGRECT but it wasn't changing anything:
let imageView = UIImageView(frame: CGRect(x: 0, y: -30, width: 100, height: 60))
imageView.contentMode = .ScaleAspectFit
let logo = UIImage(named: "holy-grail-pub-logo-header-logo")
imageView.image = logo
self.navigationItem.titleView = imageView
Any help will be appreciated!
Basically I hope you need to adjust the edgeInsets for your imageView which we cannot do directly on UIImageView as of now.
Using the method given here:
I did convert it to Swift(for your ref):
extension UIImage {
class func imageWith(image: UIImage, scaledToSize: CGSize) -> UIImage {
//UIGraphicsBeginImageContext(newSize);
// In next line, pass 0.0 to use the current device's pixel scaling factor (and thus account for Retina resolution).
// Pass 1.0 to force exact pixel size.
UIGraphicsBeginImageContextWithOptions(scaledToSize, false, 0.0)
image.drawInRect(CGRectMake(0, 0, scaledToSize.width, scaledToSize.height))
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return newImage
}
}
Using above method:
let image = UIImage.imageWith(UIImage(named: "holy-grail-pub-logo-header-logo")!, scaledToSize: CGSizeMake(80,80))
let imageView = UIImageView()
imageView.frame = CGRectMake(0, 0, 100, 100)
imageView.contentMode = .ScaleAspectFit
imageView.image = image
Now your insets become 100-80 i.e. 20. I guess this workaround would help you fixing your issue. Try this and let us know if it works.
I am trying to add a border to a UIImage I have, not UIImageView.
Here is my code:
let textView = UITextView(frame: CGRectMake(10, 20, self.view.frame.width - 20, self.view.frame.height - 20))
let attributedString = NSMutableAttributedString(string: "")
let image1 = NSTextAttachment()
image1.image = UIImage(named: "image.jpg")
let oldWidth1 = image1.image!.size.width;
//I'm subtracting 10px to make the image display nicely, accounting
//for the padding inside the textView
let scaleFactor1 = oldWidth1 / (textView.frame.size.width - 10 )
image1.image = UIImage(CGImage: image1.image!.CGImage!, scale: scaleFactor1, orientation: .Up)
let attrStringWithImage1 = NSAttributedString(attachment: image1)
attributedString.replaceCharactersInRange(NSMakeRange(0, 0), withAttributedString: attrStringWithImage1)
textView.attributedText = attributedString;
self.view.addSubview(textView)
I have that UIImage which is displaying nicely in a textView, but now I would like to add a border or some padding to the image so that the text is not so close to the image!
You could easily use Core Graphics to do this
You just have to re-draw the image in a bigger context to account for the border width – and offset the image by the border width.
Something like this should do the trick:
extension UIImage {
func imageWithBorder(borderWidth:CGFloat) -> UIImage {
// the bigger size to account for the border width
let newSize = CGSize(width: size.width+borderWidth*2.0, height: size.height+borderWidth*2.0)
// create new image context
UIGraphicsBeginImageContextWithOptions(newSize, false, scale)
// draw image with offset of the border width
self.drawInRect(CGRect(x: borderWidth, y: borderWidth, width: size.width, height: size.height))
// get image and end context
let img = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return img
}
}
If you want to give the border a fill color, you can always do that by setting the fill color, and filling the context before drawing the image.
You can then use it like this:
image1.image = UIImage(named: "image.jpg")?.imageWithBorder(10)
Side Note
You seem to be force unwrapping optionals quite a bit. Please don't. Please always safely unwrap them. My answer here might be useful for that.
The image becomes blurry once applying roundImage:
Making a UIImage to a circle form
extension UIImage
{
func roundImage() -> UIImage
{
let newImage = self.copy() as! UIImage
let cornerRadius = self.size.height/2
UIGraphicsBeginImageContextWithOptions(self.size, false, 1.0)
let bounds = CGRect(origin: CGPointZero, size: self.size)
UIBezierPath(roundedRect: bounds, cornerRadius: cornerRadius).addClip()
newImage.drawInRect(bounds)
let finalImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return finalImage
}
}
Why are you using bezierpath? Just set cornerradius for uiimageview.
If your image is larger than the imageview then you have to resize your image to your imageview size and then set cornerradius for that uiimageview.
It will work. Works for me
Replace the following line
UIGraphicsBeginImageContextWithOptions(self.size, false, 1.0)
with
UIGraphicsBeginImageContextWithOptions(self.size, view.opaque , 0.0)
try this one
let image = UIImageView(frame: CGRectMake(0, 0, 100, 100))
I recommend that you can use AlamofireImage (https://github.com/Alamofire/AlamofireImage)
It's very easily to make rounded image or circle image without losing quality.
just like this:
let image = UIImage(named: "unicorn")!
let radius: CGFloat = 20.0
let roundedImage = image.af_imageWithRoundedCornerRadius(radius)
let circularImage = image.af_imageRoundedIntoCircle()
Voila!
Your issue is that you are using scale 1, which is the lowest "quality".
Setting the scale to 0 will use the device scale, which just uses the image as is.
A side note: Functions inside a class that return a new instance of that class can be implemented as class functions. This makes it very clear what the function does. It does not manipulate the existing image. It returns a new one.
Since you were talking about circles, I also corrected your code so it will now make a circle of any image and crop it. You might want to center this.
extension UIImage {
class func roundImage(image : UIImage) -> UIImage? {
// copy
guard let newImage = image.copy() as? UIImage else {
return nil
}
// start context
UIGraphicsBeginImageContextWithOptions(newImage.size, false, 0.0)
// bounds
let cornerRadius = newImage.size.height / 2
let minDim = min(newImage.size.height, newImage.size.width)
let bounds = CGRect(origin: CGPointZero, size: CGSize(width: minDim, height: minDim))
UIBezierPath(roundedRect: bounds, cornerRadius: cornerRadius).addClip()
// new image
newImage.drawInRect(bounds)
let finalImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
// crop
let maybeCrop = UIImage.crop(finalImage, cropRect: bounds)
return maybeCrop
}
class func crop(image: UIImage, cropRect : CGRect) -> UIImage? {
guard let imgRef = CGImageCreateWithImageInRect(image.CGImage, cropRect) else {
return nil
}
return UIImage(CGImage: imgRef)
}
}