CALayer getting 1x image from Images.xcassets for iPhone6 and 6Plus - ios

Following code i am using for add CALayer into UIScrollView Layer.
UIImage *icon = [UIImage imageNamed:#“testImage”];
CGFloat imageWidth = icon.size.width;
CGFloat imageHeight = icon.size.height;
CGFloat y = 10;
CGFloat x = 10;
CGRect rect = CGRectMake(x, y, imageWidth, imageHeight);
CALayer *imageLayer = [CALayer layer];
imageLayer.frame = rect;
imageLayer.contents = (id)icon.CGImage;
[self.scrollView.layer addSublayer:imageLayer];
Thanks for help.
Please suggest if any other idea you have. like example directly get #3x image from Images.xcassets.

Please read about the contentsScale property on the CALayer class.
It is not automatically set to 3.0 for iPhone6 Plus. The automatic setting only takes place for View classes. You have to manually set it for CALayer class objects.

Related

iOS/Prevent image aspect ratio from changing when resizing

I am using the code below first to create an image thumb (using a category) and then tailor the thumb to the VC in question, for example, make it round.
Somehow, the aspect ratio of images is not getting preserved with some getting squashed vertically...so a face looks like a sideways oval while others get squashed horizontally, so a round ball looks like an upright football. In the code for individual VCs, I am using UIViewContentModeScaleAspectFill and setting clip to bounds to yes but to no avail. Also tried checking these in Storybord but still no luck.
Can anyone see what might be wrong with code below?
//code in viewDidLoad
UIImage *thumbnail = [selectedImage createThumbnailToFillSize:CGSizeMake(side, side)];
//see createThumbNail method below
self.contactImage.image = thumbnail;
//image has been selected and trimmed to thumb. Now format it
CGSize itemSize = CGSizeMake(64, 64);
UIGraphicsBeginImageContextWithOptions(itemSize, NO, UIScreen.mainScreen.scale);
CGRect imageRect = CGRectMake(0.0, 0.0, itemSize.width, itemSize.height);
self.contactImage.contentMode = UIViewContentModeScaleAspectFill;
self.contactImage.clipsToBounds = YES;
[self.contactImage.image drawInRect:imageRect];
self.contactImage.image = UIGraphicsGetImageFromCurrentImageContext();
self.contactImage.layer.cornerRadius=60.0;
UIGraphicsEndImageContext();
//Generic category to create thumb
-(UIImage *) createThumbnailToFillSize:(CGSize)size
{
CGSize mainImageSize = size;
UIImage *thumb;
CGFloat widthScaler = size.width / mainImageSize.width;
CGFloat heightScaler = size.height / mainImageSize.height;
CGSize repositionedMainImageSize = mainImageSize;
CGFloat scaleFactor;
// Determine if we should shrink based on width or hight
if(widthScaler > heightScaler)
{
// calculate based on width scaler
scaleFactor = widthScaler;
repositionedMainImageSize.height = ceil(size.height / scaleFactor);
}
else {
// calculate based on height scaler
scaleFactor = heightScaler;
repositionedMainImageSize.width = ceil(size.width / heightScaler);
}
UIGraphicsBeginImageContext(size);
CGFloat xInc = ((repositionedMainImageSize.width-mainImageSize.width) / 2.f) *scaleFactor;
CGFloat yInc = ((repositionedMainImageSize.height-mainImageSize.height) / 2.f) *scaleFactor;
[self drawInRect:CGRectMake(xInc, yInc, mainImageSize.width * scaleFactor, mainImageSize.height * scaleFactor)];
thumb = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return thumb;
}

Using a UIImageView to adjust a UIImage

I have a UIImage and I want to adjust what is shown on the device based on a UIImageView.
The UIImage is:
UIImage *image = // a PNG I have
// width = 1200
CGFloat width = image.size.width;
// height = 900
CGFloat height = image.size.height;
And I have an UIImageView
UIImageView *iview = [[UIImageView alloc] initWithFrame:CGRectMake(0.0, 0.0, 675.0, 900.0)];
How do I get my UIImage into the UIImageView without adjust the aspect ratio? I want the UIImage to be cropped off the edges?
hope this helps
-(UIImage*)crop:(CGRect)frame
{
// Find the scalefactors UIImageView's widht and height / UIImage width and height
CGFloat widthScale = self.bounds.size.width / self.image.size.width;
CGFloat heightScale = self.bounds.size.height / self.image.size.height;
// Calculate the right crop rectangle
frame.origin.x = frame.origin.x * (1 / widthScale);
frame.origin.y = frame.origin.y * (1 / heightScale);
frame.size.width = frame.size.width * (1 / widthScale);
frame.size.height = frame.size.height * (1 / heightScale);
// Create a new UIImage
CGImageRef imageRef = CGImageCreateWithImageInRect(self.image.CGImage, frame);
UIImage *croppedImage = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
return croppedImage;//(return value is uiimage)
}
and then add it to uiimageview
If u want to crop off the edges and center the position of ur image then
Set the Imageview properties to AspectFill
myImageView.contentMode = UIViewContentModeScaleAspectFill;
myImageView.clipsToBounds = YES;
Hope this helps
Try setting the contentMode property of your UIImageView to UIViewContentModeScaleAspectFill, which according to the documentation is:
The option to scale the content to fill the size of the view. Some portion of the
content may be clipped to fill the view’s bounds.
You can see the other options in the UIView documentation.

Draw rotated and scaled UILabel text inside UIImage

I have one UIScrollView with a UIImageView inside from where I obtain a cropped UIImage (considering scale, offset, bounds,...). On the other hand, I have a UILabel which I can rotate, pinch and pan anywhere over the UIScrollView. The problem comes when I try to generate the final image with the label text inside (with it's original/equivalent position, rotation,...) on the cropped UIImage (bigger than screen size).
I've tried everything. This is my last attempt trying to position the text, but it's always misplaced.
// Compute rect to draw the text inside
CGSize imageSize = inImage.size;
NSDictionary *attr = #{NSForegroundColorAttributeName: fontColor, NSFontAttributeName: textFont};
CGSize textSize = [text sizeWithAttributes:attr];
CGRect textRect = CGRectMake(labelCenterPoint.x, labelCenterPoint.y, textSize.width, textSize.height);
// Create the image
UIGraphicsBeginImageContext(imageSize);
[inImage drawInRect:CGRectMake(0, 0, imageSize.width, imageSize.height)];
// Rotate text from center
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextTranslateCTM( context, 0.5f * textSize.width, 0.5f * textSize.height ) ;
CGContextRotateCTM(context, rotation);
[text drawInRect:CGRectIntegral(textRect) withAttributes:attr];
UIImage *resultingImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
I think the problem is the textRect origin. Do I have to make the UILabel a subView of the UIScrollView too and make the textRect origin relative to the UIScrollView parameters? or am I missing something?. Is there a better way?.
Thanks in advance!.
Edit:
I have finally found an acceptable solution (although is not too much precise). I think the problem was about the two existing coordinate systems, so I tried a different approach:
// Calculate the relative position of the UILabel with respect
// to the ScrollView that contains the image
float xPosition = label.frame.origin.x - scrollView.frame.origin.x;
float yPosition = label.frame.origin.y - scrollView.frame.origin.y;
// Calculate the proportion to apply to the position
// (the image is bigger than screen)
float xProportion = image.frame.size.width / scrollView.frame.size.width;
float yProportion = image.frame.size.height / scrollView.frame.size.height;
UIImageView *testView = [[UIImageView alloc] initWithImage:image];
UILabel *tempLabel = [[UILabel alloc] initWithFrame:
CGRectMake((xPosition*xProportion),
(yPosition*yProportion),
label.frame.size.width*xProportion,
label.frame.size.height*yProportion)];
tempLabel.text = label.text;
tempLabel.font = [UIFont fontWithName:label.font.fontName
size:label.font.pointSize*3];
tempLabel.textColor = label.textColor;
tempLabel.textAlignment = NSTextAlignmentCenter;
tempLabel.transform = CGAffineTransformMakeRotation(rotation);
tempLabel.adjustsFontSizeToFitWidth = YES;
tempLabel.minimumScaleFactor = 0.05;
[testView addSubview:tempLabel];
UIGraphicsBeginImageContext(testView.image.size);
[testView.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *imageWithText = UIGraphicsGetImageFromCurrentImageContext();
I hope this may help someone. All suggestions are welcome of course.

Create UIImage from shadowed view while retaining alpha?

I have a somewhat unusual problem. In my app, I am shadowing a UIImageView using basic Quartz2d layer shadowing. Here's my code:
imageView.layer.shadowOpacity = 1.0; // Pretty self explanatory
imageView.layer.shadowRadius = 8.0; // My softness
imageView.layer.shadowColor = [UIColor blackColor].CGColor; // Color of the shadow
imageView.layer.shadowOffset = CGSizeMake(0.0, 0.0); // Offset of the shadow
This produces a nice blur behind the image view. However, I am doing some animation with this view, and the constant recalculation of the shadowing during the transitions causes a very choppy transition. What I'd like to be able to do is create a UIImage or .png file out of the image view with the blur and its alpha intact. Here's what I've already tried:
UIGraphicsBeginImageContext(CGSizeMake(320, 396));
[imageView.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIImageWriteToSavedPhotosAlbum(viewImage, nil, nil, nil);
Since I have a shadow which "grows outside" of the image view, I can't just pass his size in the UIGraphicsBeginImageContext function. I set the correct size, but the resulting image doesn't save my alpha, instead it places a white background behind the shadow, which won't work for me because my real background is a wood texture. Also, the view isn't centered in the resulting file.
I'm pretty good with UIKit, but I'm a real noobie with Quartz 2d graphics, so if there's an obvious answer to this, send it anyway. :)
Try setting your UIImageView's backgroundColor to [UIColor clearColor] - this may enable your current solution to work.
imageView.backgroundColor = [UIColor clearColor];
UIGraphicsBeginImageContext(CGSizeMake(320, 396));
[imageView.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
Source: Converting a CGLayer to a *transparent* UIImage and PNG file in CoreGraphics iphone
I've had this issue before too. My solution was not to do an image, but instead to set the shadow path to just the outline of the view you are animating.
[imageView setContentMode:UIViewContentModeScaleAspectFit];
imageView.layer.masksToBounds = NO;
imageView.layer.shadowOffset = CGSizeMake(5, 5);
imageView.layer.shadowRadius = 200;
imageView.layer.shadowOpacity = 0.5;
CGRect rect = [self rectFromImageView:imageView];
imageView.layer.shadowPath = [UIBezierPath bezierPathWithRect:rect].CGPath;
Which uses the following function which assumes the image is set to content mode aspect fit:
-(CGRect)rectFromImageView:(UIImageView *)iv {
CGRect rect = (CGRect){{0,0},iv.frame.size};
if (iv.image.size.width/iv.frame.size.width > iv.image.size.height/iv.frame.size.height) {
//rect.origin.x == 0
CGFloat sf = iv.frame.size.width/iv.image.size.width;
rect.size.height = sf*iv.image.size.height;
rect.origin.y = floor((iv.frame.size.height - rect.size.height)/2);
} else {
//rect.origin.y == 0;
CGFloat sf = iv.frame.size.height/iv.image.size.height;
rect.size.width = sf*iv.image.size.width;
rect.origin.x = floor((iv.frame.size.width - rect.size.width)/2);
}
return rect;
}
If your image is just set to fill then just using the imageView.bounds should be sufficient
Add shadow path to view like this
[view.layer setShadowPath:[[UIBezierPath bezierPathWithRect:view.bounds] CGPath]]; //add path
view.layer.shadowColor = [[UIColor blackColor] CGColor];
view.layer.shadowOffset = CGSizeMake(x, y);
view.layer.shadowRadius = rad;
view.layer.shadowOpacity = 0.2f;

How to crop UIImage on oval shape or circle shape?

Please give ideas for how to crop UIImage on oval shape or circle shape. Please share your ideas.
#import <QuartzCore/QuartzCore.h>
CALayer *imageLayer = YourImageview.layer;
[imageLayer setCornerRadius:5];
[imageLayer setBorderWidth:1];
[imageLayer setMasksToBounds:YES];
by increasing radius it will become more round-able.
As long as the image is a square, you can get a perfect circle by taking half the width as the corner radius:
[imageView.layer setCornerRadius:imageView.frame.size.width/2];
You also need to add
[imageView.layer setMasksToBounds:YES];
Swift 4.2
import QuartzCore
var imageLayer: CALayer? = YourImageview.layer
imageLayer?.cornerRadius = 5
imageLayer?.borderWidth = 1
imageLayer?.masksToBounds = true
I started looking into this a couple of weeks back. I tried all the suggestions here, none of which worked well. In the great tradition of RTFM I went and read Apple's documentation on Quartz 2D Programming and came up with this. Please try it out and let me know how you go.
The code could be fairly easily altered to crop to an elipse, or any other shape defined by a path.
Make sure you include Quartz 2D in your project.
#include <math.h>
+ (UIImage*)circularScaleAndCropImage:(UIImage*)image frame:(CGRect)frame {
// This function returns a newImage, based on image, that has been:
// - scaled to fit in (CGRect) rect
// - and cropped within a circle of radius: rectWidth/2
//Create the bitmap graphics context
UIGraphicsBeginImageContextWithOptions(CGSizeMake(frame.size.width, frame.size.height), NO, 0.0);
CGContextRef context = UIGraphicsGetCurrentContext();
//Get the width and heights
CGFloat imageWidth = image.size.width;
CGFloat imageHeight = image.size.height;
CGFloat rectWidth = frame.size.width;
CGFloat rectHeight = frame.size.height;
//Calculate the scale factor
CGFloat scaleFactorX = rectWidth/imageWidth;
CGFloat scaleFactorY = rectHeight/imageHeight;
//Calculate the centre of the circle
CGFloat imageCentreX = rectWidth/2;
CGFloat imageCentreY = rectHeight/2;
// Create and CLIP to a CIRCULAR Path
// (This could be replaced with any closed path if you want a different shaped clip)
CGFloat radius = rectWidth/2;
CGContextBeginPath (context);
CGContextAddArc (context, imageCentreX, imageCentreY, radius, 0, 2*M_PI, 0);
CGContextClosePath (context);
CGContextClip (context);
//Set the SCALE factor for the graphics context
//All future draw calls will be scaled by this factor
CGContextScaleCTM (context, scaleFactorX, scaleFactorY);
// Draw the IMAGE
CGRect myRect = CGRectMake(0, 0, imageWidth, imageHeight);
[image drawInRect:myRect];
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
Include the following code in your UIView class replacing "monk2.png" with your own image name.
- (void)drawRect:(CGRect)rect {
UIImage *originalImage = [UIImage imageNamed:[NSString stringWithFormat:#"monk2.png"]];
CGFloat oImageWidth = originalImage.size.width;
CGFloat oImageHeight = originalImage.size.height;
// Draw the original image at the origin
CGRect oRect = CGRectMake(0, 0, oImageWidth, oImageHeight);
[originalImage drawInRect:oRect];
// Set the newRect to half the size of the original image
CGRect newRect = CGRectMake(0, 0, oImageWidth/2, oImageHeight/2);
UIImage *newImage = [self circularScaleAndCropImage:originalImage frame:newRect];
CGFloat nImageWidth = newImage.size.width;
CGFloat nImageHeight = newImage.size.height;
//Draw the scaled and cropped image
CGRect thisRect = CGRectMake(oImageWidth+10, 0, nImageWidth, nImageHeight);
[newImage drawInRect:thisRect];
}
To have imageView in oval shape is not difficult.
You can do the following
UIBezierPath *path = [UIBezierPath bezierPathWithOvalInRect:yourImageView.bounds];
CAShapeLayer *maskLayer = [CAShapeLayer layer];
maskLayer.path = path.CGPath;
yourImageView.layer.mask = maskLayer;
If the rect passed to bezierPathWithOvalInRect is Square the image will be cropped to circle.
Swift Code
let path = UIBezierPath(ovalIn: yourImageView.bounds)
let maskLayer = CAShapeLayer()
maskLayer.path = path.cgPath
yourImageView.layer.mask = maskLayer
To make a RoundShape Image
Step1: in .h file
#property (strong, nonatomic) IBOutlet UIImageView *songImage;
Step2: in .m file
- (void)viewDidLoad
{
self.songImage.layer.cornerRadius = self.songImage.frame.size.width / 2;
self.songImage.clipsToBounds = YES;
//To give the Border and Border color of imageview
self.songImage.layer.borderWidth = 1.0f;
self.songImage.layer.borderColor = [UIColor colorWithRed:249/255.0f green:117/255.0f blue:44/255.0f alpha:1.0f].CGColor;
}
OR For Swift
cell.songImage.layer.cornerRadius = cell.songImage.frame.size.width / 2;
cell.songImage.clipsToBounds = true
//To give the Border and Border color of imageview
cell.songImage.layer.borderWidth = 1.0
cell.songImage.layer.borderColor = UIColor(red: 50.0/255, green: 150.0/255, blue: 65.0/255, alpha: 1.0).CGColor
After a long search I found the correct way to circle the image
Download the Support archive file from URL http://vocaro.com/trevor/blog/2009/10/12/resize-a-uiimage-the-right-way/
#import "UIImage+RoundedCorner.h"
#import "UIImage+Resize.h"
Following lines used to resize the image and convert in to round with radius
UIImage *mask = [UIImage imageNamed:#"mask.jpg"];
mask = [mask resizedImage:CGSizeMake(47, 47) interpolationQuality:kCGInterpolationHigh ];
mask = [mask roundedCornerImage:23.5 borderSize:1];
SWIFT
var vwImage = UIImageView(image: UIImage(named: "Btn_PinIt_Normal.png"))
vwImage.frame = CGRectMake(0, 0, 100, 100)
vwImage.layer.cornerRadius = vwImage.frame.size.width/2
If you only need a perfect circle, changing the shape of the UIImageView could help.
Simply add the QuartzCore framework to your project and add these lines of code somewhere in the lifecycle before the imageView is displayed:
#import <QuartzCore/QuartzCore.h>
.
.
.
//to crop your UIImageView to show only a circle
yourImageView.layer.cornerRadius = yourImageView.frame.size.width/2;
yourImageView.clipsToBounds = YES;
Check out CGImageCreateWithMask. Create a mask of your oval shape, then apply it to the image.
you should refer This ...
// Create the image from a png file
UIImage *image = [UIImage imageNamed:#"prgBinary.jpg"];
UIImageView *imageView = [[UIImageView alloc] initWithImage:image];
// Get size of current image
CGSize size = [image size];
// Frame location in view to show original image
[imageView setFrame:CGRectMake(0, 0, size.width, size.height)];
[[self view] addSubview:imageView];
[imageView release];
// Create rectangle that represents a cropped image
// from the middle of the existing image
CGRect rect = CGRectMake(size.width / 4, size.height / 4 ,
(size.width / 2), (size.height / 2)); //oval logic goes here
// Create bitmap image from original image data,
// using rectangle to specify desired crop area
CGImageRef imageRef = CGImageCreateWithImageInRect([image CGImage], rect);
UIImage *img = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
// Create and show the new image from bitmap data
imageView = [[UIImageView alloc] initWithImage:img];
[imageView setFrame:CGRectMake(0, 200, (size.width / 2), (size.height / 2))];
[[self view] addSubview:imageView];
[imageView release];
SWIFT 3 answer comes from #Mohammad Sadiq
let path = UIBezierPath.init(ovalIn: workingImgaeView.bounds)
let maskLayer = CAShapeLayer(layer: layer)
maskLayer.path = path.cgPath
workingImgaeView.layer.mask = maskLayer
This should work,
Try pasting below code in viewDidLoad().
self.myImage.layer.cornerRadius = self.myImage.frame.size.width / 2;
self.myImage.clipsToBounds = YES;

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