I have a large sized image (2048*2048px), this image is shown as 320*320 on iPhone screen. I want to do this:
In my APP, user can open large sized image(e.g. 2048*2048), the image is shown as 320*320 on iPhone screen, and there is rectangle over the image, user can move the rectangle anywhere within image on iPhone screen, e.g. rectangle(100, 100, 300, 200), then I want to clip the original sized image within the rectangle area in scale.
I tried many ways,
UIImageView *originalImageView = [[UIImage View alloc] initWithImage:originalImage]];
CGRect rect = CGRectMake(100, 100, 300, 200);
UIImage *cropImage = [UIImage imageWithCGImage:CGImageCreateWithImageInRect([originalImageView.image CGImage], rect)];
But I got the cropImage is just 300*200 sized image, not scale properly.
How about doing this, it will preserve the original image quality
CGSize bounds = CGSizeMake(320,320) // Considering image is shown in 320*320
CGRect rect = CGRectMake(100, 100, 220, 200); //rectangle area to be cropped
float widthFactor = rect.size.width * (originalImage.size.width/bounds.size.width);
float heightFactor = rect.size.height * (originalImage.size.height/bounds.size.height);
float factorX = rect.origin.x * (originalImage.size.width/bounds.size.width);
float factorY = rect.origin.y * (originalImage.size.height/bounds.size.height);
CGRect factoredRect = CGRectMake(factorX,factorY,widthFactor,heightFactor);
UIImage *cropImage = [UIImage imageWithCGImage:CGImageCreateWithImageInRect([originalImage CGImage], factoredRect)];
And most importantly if you want to crop image that imagePickerController returns, then this can be done by built in function as below,
imagePickerController.allowsEditing = YES;
Firstly resize image with size 320*320 using this method:
+(UIImage *)resizeImage:(UIImage *)image width:(float)width height:(float)height
{
CGSize newSize;
newSize.width = width;
newSize.height = height
UIGraphicsBeginImageContext(newSize);
[image drawInRect:CGRectMake(0,0,newSize.width,newSize.height)];
UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
}
Now set resized image in imageView
UIImage *resizeImage = [YourControllerName resizeImage:originalImage width:320 height:320];
UIImageView *originalImageView = [[UIImage View alloc] initWithImage:resizeImage]];
You can now crop
CGRect rect = CGRectMake(100, 100, 300, 200);
UIImage *cropImage = [UIImage imageWithCGImage:CGImageCreateWithImageInRect([originalImageView.image CGImage], rect)];
Why not calculate the scale factor (e.g. originalImageWidth/smallImageWidth)?
If the rectangle is (100,100,300,200) in your small image, you should clip your lage image at size (100*factor,100*factor,300*factor,200*factor).
Related
I am trying to crop an image taken from AVCaptureStillImageOutput but unable to properly crop at the correct rectangles.
My preview of camera video is 320x458 frame and the cropping rectangle is present inside this preview frame which has the co-ordinates and size as CGRectMake(60, 20, 200, 420).
After taking the picture, I receive the image from
NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageDataSampleBuffer];
UIImage *image = [[UIImage alloc] initWithData:imageData];
UIImage *finalImage = [self cropImage:image];
Afterwards I am trying to crop this actual image of size 1080x1920 with the below function. I am getting a wayward clipping and the resultant image is way out of the actual rectangle! ;(
- (UIImage *)cropImage:(UIImage *)oldImage {
CGRect rect = CGRectMake(60, 20, 200, 420);
CGSize boundSize = CGSizeMake(320, 458);
float widthFactor = rect.size.width * (oldImage.size.width/boundSize.width);
float heightFactor = rect.size.height * (oldImage.size.height/boundSize.height);
float factorX = rect.origin.x * (oldImage.size.width/boundSize.width);
float factorY = rect.origin.y * (oldImage.size.height/boundSize.height);
CGRect factoredRect = CGRectMake(factorX,factorY,widthFactor,heightFactor);
UIImage *croppedImage = [UIImage imageWithCGImage:CGImageCreateWithImageInRect([oldImage CGImage], factoredRect) scale:oldImage.scale orientation:oldImage.imageOrientation];
return croppedImage;
}
In the attached picture, I am trying to crop the coffee mug, but what I get is not the correct cropped image!
I think you should use PEPhotoCropEditor sample code for cropping. It's easy to use. you can download source code from https://www.cocoacontrols.com/controls/pephotocropeditor
i am also facing hard time in this i think the what you have to do is write image of file then crop that image or try out orientation issue to solve.
In my application i have used and image view to display images getting from database
in data base images are having different sizes,
for now i added image view with frame (10, 10, 300, 220).
I need to resize the frames of image view as per image size, just like Aspect Fit.
I know Aspect fit can able to resize but it do in changing width as per height ratio,
But i need to increase the height as per width ratio
i need to have width always 300, fixed but need to changes in height
For ex :
if image size is 500x1000 i need to resize imageview as 300x600
if image size is 400x600 i need to resize imageview as 300x450
You can use the following code snippet which will meets your requirements
-(UIImage *)adjustImageSizeWhenCropping:(UIImage *)image
{
float actualHeight = image.size.height;
float actualWidth = image.size.width;
float ratio=300/actualWidth;
actualHeight = actualHeight*ratio;
CGRect rect = CGRectMake(0.0, 0.0, 300, actualHeight);
// UIGraphicsBeginImageContext(rect.size);
UIGraphicsBeginImageContextWithOptions(rect.size, NO, 1.0);
[image drawInRect:rect];
UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return img;
}
resizedImage = [self imageWithImage:originalImage scaledToSize:CGSizeMake(45,45)];
self.imageView.image = resizedImage;
- (UIImage*)imageWithImage:(UIImage*)image scaledToSize:(CGSize)newSize
{
UIGraphicsBeginImageContext(newSize);
[image drawInRect:CGRectMake(0,0,newSize.width,newSize.height)];
UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
Code snippet
self.newsImage = [[UIImageView alloc] initWithFrame:CGRectMake(0,0,300,130)];
//set placeholder image or cell won't update when image is loaded
self.newsImage.image = [UIImage imageNamed:#"newsDetail.png"];
//load the image
self.newsImage.imageURL = [NSURL URLWithString:imageBig];
[imageBack addSubview:self.newsImage];
I have one image on 40*40 size but image view size 300*130. How to avoid stretching image.
I want center of the UIImageview.
Thanks in Advance !!!!
Just center the content:
self.newsImage.contentMode = UIViewContentModeCenter;
ou have to set CGSize as your image width and hight so image will not stretch and it arrange at the middle.
- (UIImage )imageWithImage:(UIImage )image scaledToFillSize:(CGSize)size
{
CGFloat scale = MAX(size.width/image.size.width, size.height/image.size.height);
CGFloat width = image.size.width * scale;
CGFloat height = image.size.height * scale;
CGRect imageRect = CGRectMake((size.width - width)/2.0f,
(size.height - height)/2.0f,
width,
height);
UIGraphicsBeginImageContextWithOptions(size, NO, 0);
[image drawInRect:imageRect];
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
I want to crop Image according to red View . There are some points to keep in mind.
1.Image can be scrolled and Zoomed.
2.Red ImageView is created Dynamically according to Image
UIImage* whole = [UIImage imageNamed:#"9.png"]; //I uses this image
CGImageRef cgImg = CGImageCreateWithImageInRect(whole.CGImage, CGRectMake(x, y, incX, incY));
UIImage* part = [UIImage imageWithCGImage:cgImg];
I just want to know How to find the Values of
x, y, incX, incY
Thanks...
Scenario 1: Normal (Not Scrolled)
Expected Result (Ignore Black Border On Top and Bottom)
Scenario 2:Scrolled
Expected Result (Ignore Black Border On Top and Bottom)
Scenario 3: Zoomed
And same Expected Result for the Zoomed One.
In all cases I want the respective Images Inside the Red Rectangle.
For all These I am Using this Code...
-(void)cropClicked:(UIButton*)sender
{
float zoomScale = 1.0 / [mainScrollView zoomScale];
CGRect rect;
rect.size.width = [redImageView bounds].size.width * zoomScale ;
rect.size.height = [redImageView bounds].size.height * zoomScale ;
rect.origin.x = ([mainScrollView bounds].origin.x + redImageView.frame.origin.x );
rect.origin.y = ([mainScrollView bounds].origin.y + redImageView.frame.origin.y );
CGImageRef cr = CGImageCreateWithImageInRect([[mainImageView image] CGImage], rect);
UIImage *cropped = [UIImage imageWithCGImage:cr];
mainImageView.image=cropped;
UIImageWriteToSavedPhotosAlbum(cropped, nil, nil, nil);
CGImageRelease(cr);
}
Well, as #HDdeveloper rightly said, you can use CGImageCreateWithImageInRect. This take 2 params, the first is the whole image, the second is the frame that you want to crop (so probably the frame of your red imageView).
The problem is that if you're targeting for both retina/non retina; if your whole image is an image #2x and you want to crop the image with the red imageview frame you have to double your frame to get the right screenshot.
So you can try with this method:
//Define the screen type:
#define isRetinaDisplay [[UIScreen mainScreen] respondsToSelector:#selector(displayLinkWithTarget:selector:)] && ([UIScreen mainScreen].scale == 2.0)
- (UIImage*)cropInnerImage:(CGRect)rect {
//Take a screenshot of the whole image
UIGraphicsBeginImageContextWithOptions(self.view.frame.size, NO, 0.0);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage* ret = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
CGRect rct;
//Double the frame if you're in retina display
if (isRetinaDisplay) {
rct=CGRectMake(rect.frame.origin.x*2, rect.frame.origin.y*2, rect.size.width*2, rect.size.height*2);
} else {
rct=rect;
}
//Crop the image from the screenshot
CGImageRef imageRef = CGImageCreateWithImageInRect([ret CGImage], rct);
UIImage *result = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
//Save and open the result images with Preview.app
[UIImagePNGRepresentation(result) writeToFile: #"/tmp/testCrop.png" atomically: YES];
system("open /tmp/testCrop.png");
[UIImagePNGRepresentation(ret) writeToFile: #"/tmp/testRet.png" atomically: YES];
system("open /tmp/testRet.png");
//
return result;
}
Where the rect parameter must be your red image frame, and self.view.frame must be the equal to the wholeImageView.frame. You can skip the last 4 lines, these are just to see in your Mac what you're cropping.
PS: i use this method to crop an image and set it as background of UIView, this is the reason i have to double the frame.
You can use CGImageRef
pass your rect in the whole image. Then call this on button click
UIImage* whole = [UIImage imageNamed:#"9.png"]; //I uses this image
CGImageRef cgImg = CGImageCreateWithImageInRect(whole.CGImage, CGRectMake(x, y, incX, incY));
UIImage* part = [UIImage imageWithCGImage:cgImg];
I'm trying to create an image for a custom style UIButton using an image from the camera roll on iPhone. The button has a circular background and effectively appears as a circle. Now I need an image to go in the middle of the button that also appears round.
How do I cut a square UIImage to appear round with transparency outside of the round area?
If masking is involved, do I need to pre-render a mask or can I create one programmatically(ex: a circle)?
Thank you!
I have never done anything like that, but try using QuartzCore framework and its' cornerRadius property. Example:
#import <QuartzCore/QuartzCore.h>
//some other code ...
UIImageView *imgView = [[UIImageView alloc]initWithFrame:CGRectMake(0, 0, 100, 100)];
imgView.layer.cornerRadius = 10.0f;
play around with it a bit and you will get what you want.
Hope it helps
Yes you can use CoreGraphics to draw the mask dynamically.
Then you can create the masked image.
Example for masking:
- (UIImage*) maskImage:(UIImage *)image withMask:(UIImage *)maskImage
{
CGImageRef maskRef = maskImage.CGImage;
CGImageRef mask = CGImageMaskCreate(CGImageGetWidth(maskRef),
CGImageGetHeight(maskRef),
CGImageGetBitsPerComponent(maskRef),
CGImageGetBitsPerPixel(maskRef),
CGImageGetBytesPerRow(maskRef),
CGImageGetDataProvider(maskRef), NULL, false);
CGImageRef maskedImageRef = CGImageCreateWithMask([image CGImage], mask);
UIImage *maskedImage = [UIImage imageWithCGImage:maskedImageRef];
CGImageRelease(maskedImageRef);
CGImageRelease(mask);
return maskedImage;
}
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*)circularScaleNCrop:(UIImage*)image: (CGRect) rect{
// 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(rect.size.width, rect.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 = rect.size.width;
CGFloat rectHeight = rect.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 circularScaleNCrop:originalImage :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];
}
Here is a quick way to create rounded corners on a square ImageView to make it look like a perfect circle. Basically you apply a corner radius equal to 1/2 the width (width == height on a square image).
#import <QuartzCore/QuartzCore.h> //you need QuartzCore
...
float width = imageView.bounds.size.width; // we can also use the frame property instead of bounds since we just care about the Size and don't care about position
imageView.layer.cornerRadius = width/2;
{
imageView.layer.cornerRadius = imageView.frame.size.height /2;
imageView.layer.masksToBounds = YES;
imageView.layer.borderWidth = 0;
}
UIImage category to mask an image with a circle:
UIImage *originalImage = [UIImage imageNamed:#"myimage.png"];
UImage *myRoundedImage = [UIImage roundedImageWithImage:originalImage];
Get it here.
I have another solution:
- (UIImage *)roundedImageWithRect:(CGRect)rect radius:(CGFloat)radius
{
UIGraphicsBeginImageContextWithOptions(rect.size, NO, 0);
UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:CGRectMake(0, 0, rect.size.width, rect.size.height) cornerRadius:radius];
CGFloat imageRatio = self.size.width / self.size.height;
CGSize imageSize = CGSizeMake(rect.size.height * imageRatio, rect.size.height);
CGRect imageRect = CGRectMake(0, 0, imageSize.width, imageSize.height);
[path addClip];
[self drawInRect:imageRect];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
This variant is better for performance than set cornerRadius directly.
Personally, I'd create a transparent circle image with opaque corners to overlay the photo. This solution is only suitable where you will be placing the image in one place on the UI, and assumes the opaque corners will blend in with the background.
Following is the answer I given in How to crop UIImage on oval shape or circle shape? to make the image circle. It works for me..
Download the Support archive file
#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];
Just use
_profilePictureImgView.layer.cornerRadius = 32.0f;
_profilePictureImgView.layer.masksToBounds = YES;