I am cropping an UIImage using the following code:
UIImage *image=[info objectForKey:UIImagePickerControllerOriginalImage];
CGRect rect = CGRectMake(10,10,700, 700);
CGImageRef imageRef = CGImageCreateWithImageInRect([image CGImage], rect);
UIImage *img = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
I am able to crop with a height, but if I increased my Y axis it is not getting cropped.
CGRect rect = CGRectMake(10,50,700, 700);
Any solutions ?
Check out this github library which do what you want imageCroppedToRect
- (UIImage *)imageCroppedToRect:(CGRect)rect {
// CGImageCreateWithImageInRect's `rect` parameter is in pixels of the image's coordinates system. Convert from points.
CGFloat scale = self.scale;
rect = CGRectMake(rect.origin.x * scale, rect.origin.y * scale, rect.size.width * scale, rect.size.height * scale);
CGImageRef imageRef = CGImageCreateWithImageInRect(self.CGImage, rect);
UIImage *cropped = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
return cropped;
}
Logically, for the cropping of the image only the size is relevant. So you have to adjust your width and height accordingly. The x and y coordinates of your frame will only change the position, not the size.
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Possible Duplicate:
Cropping a UIImage
I saw many tutorials about cropping images and am trying my luck but with no success.
I need to crop the image from AVFoundation. Since when the image is being taken from the camera it is rotated left from Portrait mode, I also need to rotate it right and my x and y are opposite. The problem is that if I send the frame of the image where I would it to reside, it seems to me that there is no correlation in the size of the image and the rectangle.
The code is:
#property (weak, nonatomic) IBOutlet UIView *videoPreviewView;
...
...
int width = videoPreviewView.frame.size.width;
int height = videoPreviewView.frame.size.height;
int x = videoPreviewView.frame.origin.x;
int y = videoPreviewView.frame.origin.y;
CGRect croprect = CGRectMake(y, x,height,width);
// Draw new image in current graphics context
CGImageRef imageRef = CGImageCreateWithImageInRect([sourceImage CGImage], croprect);
// Create new cropped UIImage
UIImage *resultImage = [UIImage imageWithCGImage:imageRef scale:[sourceImage scale] orientation:UIImageOrientationRight];
When I print the size of the frame I get:
(4.5,69.5,310,310)
and the image size is:
(720,1280)
How can I perform cropping in any image resolution?
I tried multiplying the values with image.scale - however, the value is 1.00
Try this one.This will definitely help you out. https://github.com/barrettj/BJImageCropper
To resize image, Try this
UIImage *image = [UIImage imageNamed:#"image.png"];
CGSize itemSize = CGSizeMake((your Width), (your Height));
UIGraphicsBeginImageContext(itemSize);
CGRect imageRect = CGRectMake(0.0, 0.0, itemSize.width, itemSize.height);
[image drawInRect:imageRect];
UIImage * yourCroppedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
To Crop,
// Create new image context
UIGraphicsBeginImageContext(SIZE);
// Create CGRect for image
CGRect newRect = CGRectMake(x, y,SIZE.width,SIZE.height);
// Draw the image into the rect
[ORIGINALIMAGE drawInRect:newRect];
// Saving the image, ending image context
UIImage * newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
I am using one simple cropping on UIImage, however after cropping when we check the final image, it gets rotated in iPhone. Below is my code used for cropping.
CGRect visibleRect;
float scale = 1.0f/scrollView.zoomScale;
visibleRect.origin.x = scrollView.contentOffset.x * scale;
visibleRect.origin.y = scrollView.contentOffset.y * scale;
visibleRect.size.width = scrollView.bounds.size.width * scale;
visibleRect.size.height = scrollView.bounds.size.height * scale;
finalImage = imageFromView(displayImageView.image, &visibleRect);
UIImage* imageFromView(UIImage* srcImage, CGRect* rect) {
CGImageRef cr = CGImageCreateWithImageInRect(srcImage.CGImage, *rect);
UIImage* cropped = [UIImage imageWithCGImage:cr];
CGImageRelease(cr);
return cropped;
}
Please let me know if i am doing any kind of wrong thing.
You need to call this method after crpping it
-(UIImage*)rotateImage:(UIImage*)image
{
UIGraphicsBeginImageContext(image.size);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextDrawImage(context, CGRectMake(0 , 0, image.size.width , image.size.height), [image CGImage]);
CGContextRotateCTM (context, radians(90));
CGImageRef cgImage = nil;
cgImage = CGBitmapContextCreateImage(context);
UIImage *img = [UIImage imageWithCGImage:cgImage];
return img;
}
I am performing rotation on an UIImageView and then i try to crop a part of it and save it as an UIImage. The UIImageView rotates however it always crops the same part of the photo. So the cropping does not take into account the image rotation. What am i doing wrong?
//rotate image
CGRect new = CGRectMake(0, 0, 100, 50);
CGAffineTransform rotation = CGAffineTransformMakeRotation(5);
[photo setTransform:rotation];
// crop image
CGImageRef imageRef = CGImageCreateWithImageInRect([photo.image CGImage], new);
UIImage *croppedImage = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
// display crop bounds
UIView* faceBounds = [[UIView alloc] initWithFrame:new];
faceBounds.layer.borderWidth = 2;
faceBounds.layer.borderColor = [[UIColor redColor] CGColor];
Use the following snippet for rotating image data.
The input data is inAngle (angle in radians) and inImage (UIImage instance).
What this does, it creates an image context, applies the transformation to it and draws the original image into that context. The resulting image data will now be stored in resultImage.
The first three lines handle the calculation of the bounding result image frame.
UIView *rotatedViewBox = [[UIView alloc] initWithFrame:CGRectMake(0.0f, 0.0f, inImage.size.width, inImage.size.height)];
rotatedViewBox.transform = CGAffineTransformMakeRotation(inAngle);
CGSize rotatedSize = rotatedViewBox.frame.size;
UIGraphicsBeginImageContext(rotatedSize);
CGContextRef bitmap = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(bitmap, rotatedSize.width / 2.0f, rotatedSize.height / 2.0f);
CGContextRotateCTM(bitmap, inAngle);
CGContextScaleCTM(bitmap, 1.0f, -1.0f);
CGContextDrawImage(bitmap, CGRectMake(-inImage.size.width / 2.0f,
-inImage.size.height / 2.0f,
inImage.size.width,
inImage.size.height),
inImage.CGImage);
UIImage *resultImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
This is too late for now but For now someone can try this
I am working on Camera Application user are taking a picture its fine,but i want to crop anywhere in that image and send it to server. How can I do this?
Check out this link for details:
http://www.hive05.com/2008/11/crop-an-image-using-the-iphone-sdk/
Basic code:
- (UIImage*)imageByCropping:(UIImage *)imageToCrop toRect:(CGRect)rect
{
//create a context to do our clipping in
UIGraphicsBeginImageContext(rect.size);
CGContextRef currentContext = UIGraphicsGetCurrentContext();
//create a rect with the size we want to crop the image to
//the X and Y here are zero so we start at the beginning of our
//newly created context
CGRect clippedRect = CGRectMake(0, 0, rect.size.width, rect.size.height);
CGContextClipToRect( currentContext, clippedRect);
//create a rect equivalent to the full size of the image
//offset the rect by the X and Y we want to start the crop
//from in order to cut off anything before them
CGRect drawRect = CGRectMake(rect.origin.x * -1,
rect.origin.y * -1,
imageToCrop.size.width,
imageToCrop.size.height);
//draw the image to our clipped context using our offset rect
CGContextDrawImage(currentContext, drawRect, imageToCrop.CGImage);
//pull the image from our cropped context
UIImage *cropped = UIGraphicsGetImageFromCurrentImageContext();
//pop the context to get back to the default
UIGraphicsEndImageContext();
//Note: this is autoreleased
return cropped;
}
I think i can provide a better solution to that large amount of code.
- (void)viewDidLoad
{
[super viewDidLoad];
// do something......
UIImage *croppedImage = [self imageByCropping:[UIImage imageNamed:#"SomeImage.png"] toRect:CGRectMake(10, 10, 100, 100)];
}
- (UIImage*)imageByCropping:(UIImage *)imageToCrop toRect:(CGRect)rect
{
CGImageRef imageRef = CGImageCreateWithImageInRect([imageToCrop CGImage], rect);
UIImage *cropped = [UIImage imageWithCGImage:imageRef];
return cropped;
}
I developing the simple UIApplication in which i want to crop the UIImage (in .jpg format) with help of CGContext. The developed code till now as follows,
CGImageRef graphicOriginalImage = [originalImage.image CGImage];
UIGraphicsBeginImageContext(originalImage.image.size);
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGBitmapContextCreateImage(graphicOriginalImage);
CGFloat fltW = originalImage.image.size.width;
CGFloat fltH = originalImage.image.size.height;
CGFloat X = round(fltW/4);
CGFloat Y =round(fltH/4);
CGFloat width = round(X + (fltW/2));
CGFloat height = round(Y + (fltH/2));
CGContextTranslateCTM(ctx, 0, image.size.height);
CGContextScaleCTM(ctx, 1.0, -1.0);
CGRect rect = CGRectMake(X,Y ,width ,height);
CGContextDrawImage(ctx, rect, graphicOriginalImage);
croppedImage = UIGraphicsGetImageFromCurrentImageContext();
return croppedImage;
}
The above code is worked fine but it can't crop image.
The original image memory and cropped image memory i will got same(equal to original image memory).
The above code is right for cropping the image??????????????????
Here is a good way to crop an image to a CGRect:
- (UIImage*)imageByCropping:(UIImage *)imageToCrop toRect:(CGRect)rect
{
//create a context to do our clipping in
UIGraphicsBeginImageContext(rect.size);
CGContextRef currentContext = UIGraphicsGetCurrentContext();
//create a rect with the size we want to crop the image to
//the X and Y here are zero so we start at the beginning of our
//newly created context
CGRect clippedRect = CGRectMake(0, 0, rect.size.width, rect.size.height);
CGContextClipToRect( currentContext, clippedRect);
//create a rect equivalent to the full size of the image
//offset the rect by the X and Y we want to start the crop
//from in order to cut off anything before them
CGRect drawRect = CGRectMake(rect.origin.x * -1,
rect.origin.y * -1,
imageToCrop.size.width,
imageToCrop.size.height);
//draw the image to our clipped context using our offset rect
CGContextDrawImage(currentContext, drawRect, imageToCrop.CGImage);
//pull the image from our cropped context
UIImage *cropped = UIGraphicsGetImageFromCurrentImageContext();
//pop the context to get back to the default
UIGraphicsEndImageContext();
//Note: this is autoreleased
return cropped;
}
Or another way:
- (UIImage *)imageByCropping:(UIImage *)imageToCrop toRect:(CGRect)rect
{
CGImageRef imageRef = CGImageCreateWithImageInRect([imageToCrop CGImage], rect);
UIImage *cropped = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
return cropped;
}
From http://www.hive05.com/2008/11/crop-an-image-using-the-iphone-sdk/.
The context you create to draw the image has the same size that the original image. That's why they have the same size.
If you don't want to re-invent the wheel, take a look at the TouchCode project on Google Code. You will find UIImage categories that do the job (see UIImage_ThumbnailExtensions.m).