I created empty gray UIImage, using below code
let size = CGSize(width: 212, height: 332)
UIGraphicsBeginImageContextWithOptions(size, true, 0)
UIColor.gray.setFill()
UIRectFill(CGRect(x: 0, y: 0, width: size.width, height: size.height))
let backgroundImage2: UIImage? = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
It shows output as
Now I need to put UIImage on specific area in this UIImage. as shown in below Image. Say top, left, right should be 30 pixels, and bottom more than that, say 200 pixels. maintaining inner image aspect ratio.
Use two image views (either UIImageView or GLKView), making the "image" a subview of the "gray background" view. After positioning the "image" correctly, merge the two images into one.
Here's an extension to UIView that I use:
extension UIView {
public func createImage() -> UIImage {
UIGraphicsBeginImageContextWithOptions(
CGSize(width: self.frame.width, height: self.frame.height), true, 1)
self.layer.render(in: UIGraphicsGetCurrentContext()!)
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return image!
}
}
Related
I am trying to draw a "zoomed-in" portion of UIImage and can't find a way to do that...
Say I have an image sized 1000x1000, and I zoom-in to the top left (x:0, y:0 width: 500, height: 500), and I want to draw that portion into another 1000x1000 image.
I am using UIGraphicsImageRenderer but UIImage draw method doesn't accept any source rect, only destination rect (and it draws the entire image).
I was able to achieve what I want by specifying a larger rect in the draw method, but that crashes when the zoom-in level is big (out-of-memory).
This is what I tried:
let srcImg: UIImage = {some UIImage sized 1000x1000}
let renderer = UIGraphicsImageRenderer(size: CGSize(width: 1000, height: 1000))
let scaled = renderer.image { ctx in
srcImg.draw(in: CGRect(origin: CGPoint.zero, size: CGSize(width: 2000, height: 2000)))
}
Basically I am trying to achieve something like the drawImage API of HTML5 canvas, which gets both src and dst rectangles...
Thanks.
Use the UIImage extension from this answer: https://stackoverflow.com/a/28513086/6257435
If I understand your question correctly -- you want to clip the top-left 500x500 pixels from a 1000x1000 image, and scale that up to 1000x1000 -- here is a simple example using that extension:
if let img1000x1000 = UIImage(named: "img1000x1000") {
if let topLeft500x500 = img1000x1000.cropped(to: CGRect(x: 0, y: 0, width: 500, height: 500)) {
if let new1000x1000 = topLeft500x500.filled(to: CGSize(width: 1000, height: 1000)) {
// do something with new 1000x1000 image
print()
}
}
}
I have multiple sizes of frames, which can be hard coded, or server will decide. I have to select Image from Gallery, which definitely can be of many dimensions.
I am selecting Image from Gallery
I am generating white background UIImage, using code.
let size = CGSize(width: 424/2, height: 664/2)
UIGraphicsBeginImageContextWithOptions(size, true, 0)
UIColor.white.setFill()
UIRectFill(CGRect(x: 0, y: 0, width: size.width, height: size.height))
let background_image: UIImage? = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
Now, what I want, to make another Image, which keep Leading 20 pixel, Top 20 Pixel, and width and height 20 pixel smaller than original background.
How can I achieve it.
What I tried before coming to StackOverflow.
func mergedImageWith(frontImage:UIImage?, backgroundImage: UIImage?) -> UIImage{
if (backgroundImage == nil) {
return frontImage!
}
let size = CGSize(width: 424/2, height: 664/2)
UIGraphicsBeginImageContextWithOptions(size, true, 0)
UIColor.white.setFill()
UIRectFill(CGRect(x: 0, y: 0, width: size.width, height: size.height))
let backgroundImage2: UIImage? = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
UIGraphicsBeginImageContextWithOptions(size, false, 0.0)
backgroundImage2?.draw(in: CGRect.init(x: 0, y: 0, width: size.width, height: size.height))
frontImage?.draw(in: getAspectFillFrame(sizeImageView: size2, sizeImage: (frontImage?.size)!))
let newImage:UIImage = UIGraphicsGetImageFromCurrentImageContext()!
UIGraphicsEndImageContext()
return newImage
}
here background image is created with aspect fill, but issue is of starting position and complete height and width.
In very simple words. Its like making custom frames and merge them with images(aspect fill) for printing.
can anyone help me out
Thanks.
Try not ending your image context until all of the images are drawn (I am also including some code that I have working, edited down a bit)
class layeredImageView: UIImageView {
var imageBackground:UIImage!
var imageForeground:UIImage!
UIGraphicsBeginImageContextWithOptions(self.frame.size, false, UIScreen.main.scale)
self.image?.draw(in: self.frame)
imageBackground.draw(in: CGRect(<rect>)
imageForeground.draw(in: CGRect(<rect>)
self.image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
}
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
}
}
I would like to make partial screenshot in my project.
However, I tried the output screenshot is not good that I want to be.
Here is my code.
let size = CGSize(width: 398, height: 300)
UIGraphicsBeginImageContextWithOptions(size, false, 0);
view.layer.render(in: UIGraphicsGetCurrentContext()!)
var sourceImage = UIGraphicsGetImageFromCurrentImageContext()
sourceImage?.draw(at: CGPoint(x: 0, y: 0))
var cropimage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
UIImageWriteToSavedPhotosAlbum(cropimage!,nil,nil,nil)
I would like to save only white View. If I set width and height, the output image is small and does not get completely.
Anyone help me please?
extend UIView and capture an image of that white view
// Untested
import UIKit
extension UIView {
func capture() -> UIImage {
UIGraphicsBeginImageContextWithOptions(self.frame.size, self.opaque, UIScreen.mainScreen().scale)
self.layer.renderInContext(UIGraphicsGetCurrentContext()!)
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return image
}
}
usage:
let whiteImage = myWhiteView.capture()
i read here many guides how to create a new image merging two existing ones, using the UIGraphics and the layer.render methods for the two UIImageViews, and finally i can create an then save my new image. The problem is that i can't understand how to put the second UIImageView where i want, at the bottom for example. I 'll post now a image of an merged image and the function that my code run making this possible.
Captured merged photo
And here's my code that do the trick:
extension UIImage {
class func imageWithWatermark(image1: UIImageView, image2: UIImageView) -> UIImage {
UIGraphicsBeginImageContextWithOptions(image1.bounds.size, false, 0.0)
let frame = image1.frame
image2.frame = CGRect(x: 0, y: frame.size.height * 0.80, width: frame.size.width, height: frame.size.height * 0.20 )
image1.layer.render(in: UIGraphicsGetCurrentContext()!)
image2.layer.render(in: UIGraphicsGetCurrentContext()!)
let img = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return img!
}
}
And then my func that saves the merged image:
func addWatermark() {
let newImage = UIImage.imageWithWatermark(image1: cameraPreview, image2: provaImage)
UIImageWriteToSavedPhotosAlbum(newImage, nil,nil,nil)
}
You can use this function which merge two images and the second will be replaces on bottom
func mergeTwoImageSeconInBottom(backgroundImage: UIImage, imageOnBottom: UIImage) -> UIImage {
let size = YOUR_CG_SIZE
UIGraphicsBeginImageContextWithOptions(size, false, 0.0)
backgroundImage.draw(in: CGRect(x: 0, y: 0, width: size.width, height: size.height))
imageOnBottom.draw(at: CGPoint(x: (size.width - imageOnBottom.size.width) / 2, y: size.height - imageOnBottom.size.height))
let newImage: UIImage = UIGraphicsGetImageFromCurrentImageContext()!
UIGraphicsEndImageContext()
return newImage
}