I want to crop selected image from a gallery (Programmatically). I have done a lot of research and got the [tutor](http://iosdevelopertips.com/graphics/how-to-crop-an-image.html) gone through this.still getting confuse whether cropping of image can be done by using UIImagePickerController or UIImageView.I'm not getting from where to start or how to start?. please suggest me the right way any one.
Answer : CGImage Reference
1) Create a 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));
2) 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);
3) Create and show the new image from bitmap data :
imageView = [[UIImageView alloc] initWithImage:img];
Useful Links :
1) Working with UIGestureRecognizers.
2) Cropping and Resizing Images from Camera in iOS and Objective-C.
GoodLuck !!!
Related
I have an image with multiple icons, and I have the position and the size of the icon that I want to show.
The question is, how can I show just part of an image in a UIImageView so I can show only the icon that I want to?
Is it possible to show the icon correctly in 1x, 2x, and 3x, even if the image gets a bit pixelated?
You can crop a part of the image and create a new UIImage from it with CGImageCreateWithImageInRect:
CGRect cropRect = CGRectMake(x,y,width,height); //Calculate the rect you'd like to show
CGImageRef imageRef = CGImageCreateWithImageInRect(originalImage.CGImage, cropRect);
UIImage* outImage = [UIImage imageWithCGImage:imageRef scale:originalImage.scale orientation:originalImage.imageOrientation];
CGImageRelease(imageRef);
This question already has answers here:
Cropping an UIImage
(25 answers)
Closed 8 years ago.
I'm making an application that need to crop the image to another image.
i want to crop the source Image ( like green rectangle) to destination image ( like white rectangle). I can get the size of source and destination image and the offset x and y . How can i got that crop image and save it to library?
You can see the image attach here:
How can I crop to that image? and if you can please give me an example source code
so much thanks for that
Use this method and pass image, rect as parameter. You can specify y offset and x offset in cropRect
-(UIImage *)cropImage:(UIImage *)image rect:(CGRect)cropRect
{
CGImageRef imageRef = CGImageCreateWithImageInRect([image CGImage], cropRect);
UIImage *cropedImg = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
return cropedImg;
}
Check Below Code:
-(UIImage *)imageWithImageSimple:(UIImage*)image scaledToSize:(CGSize)newSize
{
UIGraphicsBeginImageContext(newSize);
[image drawInRect:CGRectMake(0,0,newSize.width,newSize.height)];
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
Check below Links For reference:
http://code4app.net/ios/Image-crop-demo/501e1f3f6803faea5d000000
http://code4app.net/ios/Photo-Cropper-View-Controller/4f95519c06f6e7d870000000
http://code4app.net/ios/Image-Cropper/4f8cc87f06f6e7d86c000000
http://code4app.net/ios/Simple-Image-Editor-View/4ff2af4c6803fa381b000000
Get sample code from here. Then you can customise your own.
I have an implementation of AVCaptureSession and my goal is for the user to take a photo and only save the part of the image within the red square border, as shown below:
AVCaptureSession's previewLayer (the camera) spans from (0,0) (top left) to the bottom of my camera controls bar (the bar just above the view that contains the shutter). My navigation bar and controls bar are semi-transparent, so the camera can show through.
I'm using [captureSession setSessionPreset:AVCaptureSessionPresetPhoto]; to ensure that the original image being saved to the camera roll is like Apple's camera.
The user will be able to take the photo in portrait, landscape left and right, so the cropping method must take this into account.
So far, I've tried to crop the original image using this code:
DDLogVerbose(#"%#: Image crop rect: (%f, %f, %f, %f)", THIS_FILE, self.imageCropRect.origin.x, self.imageCropRect.origin.y, self.imageCropRect.size.width, self.imageCropRect.size.height);
// Create new image context (retina safe)
UIGraphicsBeginImageContextWithOptions(CGSizeMake(self.imageCropRect.size.width, self.imageCropRect.size.width), NO, 0.0);
// Create rect for image
CGRect rect = self.imageCropRect;
// Draw the image into the rect
[self.captureManager.stillImage drawInRect:rect];
// Saving the image, ending image context
UIImage *croppedImage = UIGraphicsGetImageFromCurrentImageContext();
However, when I look at the cropped image in the camera roll, it seems that it has just squashed the original image, and not discarded the top and bottom parts of the image like I'd like. It also results in 53 pixels of white space at the top of the "cropped" image, likely because of the y position of my CGRect.
This is my logging output for the CGRect:
Image crop rect: (0.000000, 53.000000, 320.000000, 322.000000)
This also describes the frame of the red bordered view in the superview.
Is there something crucial I'm overlooking?
P.S. The original image size (taken with a camera in portrait mode) is:
Original image size: (2448.000000, 3264.000000)
You can crop images with CGImageCreateWithImageInRect:
CGImageRef imageRef = CGImageCreateWithImageInRect([uncroppedImage CGImage], bounds);
UIImage *croppedImage = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
Don't forget to add scale parameter otherwise you will get low resolution image
CGImageRef imageRef = CGImageCreateWithImageInRect([uncroppedImage CGImage], CGRectMake(0, 0, 30, 120));
[imageView setImage:[UIImage imageWithCGImage:imageRef scale:[[UIScreen mainScreen] scale] orientation:UIImageOrientationUp]];
CGImageRelease(imageRef);
Swift 3:
let imageRef:CGImage = uncroppedImage.cgImage!.cropping(to: bounds)!
let croppedImage:UIImage = UIImage(cgImage: imageRef)
I can access image's by using [UIImage imageNamed:#"nameOfPng.png"]; if I have a single image in a .png file. But if we are having a multiple images in a .png file, how do we access sub images from a single UIImage ?
This is the single .png file. If i wanted to get the red button image or any other button image how can I do this.
What you are looking to do is to create a clipped UIImage from a section of your current image. I usually do it this way, changing the clip rect each time. Where srcImage is your original image.
//Set the clip rectangle
CGRect clipRect = CGRectMake(0, 0, 100, 100);
//Get sub image
CGImageRef drawImage = CGImageCreateWithImageInRect(srcImage.CGImage, clipRect);
UIImage *newImage = [UIImage imageWithCGImage:drawImage];
CGImageRelease(drawImage);
I want to crop an ellipse from an image in ios. Using core image framework, I know know to crop a reactangular region.
Using core graphics, I am able to clip the elliptical region. But, the size of the cropped image is same as the size of the original image as I am applying mask to area outside the ellipse.
So, the goal is to crop the elliptical region from an image and size of cropped image won't exceed the rectangular bounds of that image.
Any help would be greatly appreciated. Thanks in advance.
You have to create a context in the correct size, try the following code:
- (UIImage *)cropImage:(UIImage *)input inElipse:(CGRect)rect {
CGRect drawArea = CGRectMake(-rect.origin.x, -rect.origin.y, input.size.width, input.size.height);
UIGraphicsBeginImageContext(rect.size);
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextAddEllipseInRect(ctx, CGRectMake(0, 0, rect.size.width, rect.size.height));
CGContextClip(ctx);
[input drawInRect:drawArea];
UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return img;
}
Maybe you have to adjust the drawArea to your needs as i did not test it.