I'm trying to get an uiimage from a calayer that I had previously rotated:
//Creates the rotation affine transform
m_transformada = CGAffineTransformIdentity;
m_transformada = CGAffineTransformRotate(m_transformada, M_PI / 4);
// Apply the affine transform to a UIVIewImage object
m_PhotoView.transform = m_transformada;
// Get's the UIImage from the UIViewImage
UIGraphicsBeginImageContext([m_PhotoView.layer frame].size);
[m_PhotoView.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *outputImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
The outputImage is not rotated... anyone knows why?
Thanks,
The transform on the layer affects its geometry in its superlayer, not the layer itself.
Something like this will work (this meant to be mixed in and/or otherwise adapted):
- (UIImage*)renderToImageRotated:(float)scale {
float tx = self.frame.size.width;
float ty = self.frame.size.height;
CGSize size = CGSizeMake(self.frame.size.height, self.frame.size.width);
UIGraphicsBeginImageContextWithOptions(size, NO, scale);
CGContextRef c = UIGraphicsGetCurrentContext();
CGContextTranslateCTM (c, ty/2, tx/2);
CGContextRotateCTM(c, M_PI/2);
CGContextTranslateCTM (c, -tx/2, -ty/2);
[self.layer renderInContext:c];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
Related
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 have a photo app where you can add stickers in one section. When you're finished I want to save the image. Here is the code that I have to do that.
if(UIGraphicsBeginImageContextWithOptions != NULL)
{
UIGraphicsBeginImageContextWithOptions(self.view.frame.size, YES, 2.5);
} else {
UIGraphicsBeginImageContext(self.view.frame.size);
}
CGContextRef contextNew=UIGraphicsGetCurrentContext();
[self.view.layer renderInContext:contextNew];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
Now the image that gets saved is the full screen of the image, which is fine, but now I need to crop the image and I don't know how. You can see the image at the link below:
http://dl.dropbox.com/u/19130454/Photo%202012-04-09%201%2036%2018%20PM.png
I need to crop:
91px from the left and right
220px from the bottom
Any help would be greatly appreciated. If I haven't explained things clearly, please let me know and I'll do my best to re-explain.
How about something like this
CGRect clippedRect = CGRectMake(self.view.frame.origin.x+91, self.view.frame.origin.y, self.view.frame.size.width-91*2, self.view.frame.size.height-220);
CGImageRef imageRef = CGImageCreateWithImageInRect([image CGImage], clippedRect);
UIImage *newImage = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
Following code may help you.
You should get the correct cropFrame fist by below method
-(CGRect)cropRectForFrame:(CGRect)frame
{
// NSAssert(self.contentMode == UIViewContentModeScaleAspectFit, #"content mode must be aspect fit");
CGFloat widthScale = imageview.superview.bounds.size.width / imageview.image.size.width;
CGFloat heightScale = imageview.superview.bounds.size.height / imageview.image.size.height;
float x, y, w, h, offset;
if (widthScale<heightScale) {
offset = (imageview.superview.bounds.size.height - (imageview.image.size.height*widthScale))/2;
x = frame.origin.x / widthScale;
y = (frame.origin.y-offset) / widthScale;
w = frame.size.width / widthScale;
h = frame.size.height / widthScale;
} else {
offset = (imageview.superview.bounds.size.width - (imageview.image.size.width*heightScale))/2;
x = (frame.origin.x-offset) / heightScale;
y = frame.origin.y / heightScale;
w = frame.size.width / heightScale;
h = frame.size.height / heightScale;
}
return CGRectMake(x, y, w, h);
}
Then you need to call this method to get cropped image
- (UIImage *)imageByCropping:(UIImage *)image toRect:(CGRect)rect
{
// you need to update scaling factor value if deice is not retina display
UIGraphicsBeginImageContextWithOptions(rect.size,
/* your view opaque */ NO,
/* scaling factor */ 2.0);
// stick to methods on UIImage so that orientation etc. are automatically
// dealt with for us
[image drawAtPoint:CGPointMake(-rect.origin.x, -rect.origin.y)];
UIImage *result = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return result;
}
- (UIImage*)imageByCropping:(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,
self.size.width,
self.size.height);
//draw the image to our clipped context using our offset rect
// CGContextDrawImage(currentContext, drawRect, self.CGImage);
[self drawInRect:drawRect]; // This will fix getting inverted image from context.
//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;
}
Refer the below link for crop image
https://github.com/myang-git/iOS-Image-Crop-View
** How to Use **
Very easy! It is created to be a drop-in component, so no static library, no extra dependencies. Just copy ImageCropView.h and ImageCropView.m to your project, and implement ImageCropViewControllerDelegate protocol.
Use it like UIImagePicker:
- (void)cropImage:(UIImage *)image{
ImageCropViewController *controller = [[ImageCropViewController alloc] initWithImage:image];
controller.delegate = self;
[[self navigationController] pushViewController:controller animated:YES];
}
- (void)ImageCropViewController:(ImageCropViewController *)controller didFinishCroppingImage:(UIImage *)croppedImage{
image = croppedImage;
imageView.image = croppedImage;
[[self navigationController] popViewControllerAnimated:YES];
}
- (void)ImageCropViewControllerDidCancel:(ImageCropViewController *)controller{
imageView.image = image;
[[self navigationController] popViewControllerAnimated:YES];
}
I have some transformable UIImageViews (decorates on a photo), which user can drag, pinch and rotate. After editing, I want the app to generate the final image. How can I draw the UIImageViews with their transform property considered.
My first solution is using renderInContext, but it can only generate a 320x480 image. Can I generate an image with any resolution?
Then I use code as follows:
UIGraphicsBeginImageContext(CGSizeMake(640.0f, 896.0f));
CGContextRef currentContext = UIGraphicsGetCurrentContext();
UIImage *backgroundImage = [[UIImage alloc] initWithContentsOfFile:[[NSBundle mainBundle] pathForResource:#"fittingBackground" ofType:#"jpg"]];
[backgroundImage drawInRect:CGRectMake(0.0f, 0.0f, 640.0f, 896.0f)];
CGContextSaveGState(currentContext);
CGContextConcatCTM(currentContext, self.photoImageView.transform);
CGRect photoFrame = self.photoImageView.frame;
[self.photoImageView.image drawInRect:CGRectMake(photoFrame.origin.x * 2, photoFrame.origin.y * 2, photoFrame.size.width * 2, photoFrame.size.height * 2)];
CGContextRestoreGState(currentContext);
CGContextSaveGState(currentContext);
CGContextConcatCTM(currentContext, self.productImageView.transform);
CGRect productFrame = self.productImageView.frame;
[self.productImageView.image drawInRect:CGRectMake(productFrame.origin.x * 2, productFrame.origin.y * 2, productFrame.size.width * 2, productFrame.size.height * 2)];
CGContextRestoreGState(currentContext);
UIImage *resultImage = [UIImage imageWithCGImage:CGBitmapContextCreateImage(currentContext)];
UIGraphicsEndImageContext();
However, the result seems to be weird. And I've logged the frame, bounds and center. I don't know which Rect should I use in drawInRect after applying transform?
Try this,
-(void)drawBackgroundInLayer:(CALayer*)destinationLayer {
CGFloat scaledFactor = [[UIScreen mainScreen] scale];
CGRect layerFrame = destinationLayer.frame;
CGRect scaledRect = CGRectMake(layerFrame.origin.x,
layerFrame.origin.y,
(layerFrame.size.width)*scaledFactor,
(layerFrame.size.height)*scaledFactor);
// Get the size and do some drawings
CGSize sizeBack = CGSizeMake(layerFrame.size.width*scaledFactor, layerFrame.size.height*scaledFactor);
UIGraphicsBeginImageContext(sizeBack);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetRGBFillColor(context, 0., 0., 0., 1.);
drawBorder(context, scaledRect);
UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
if (destinationLayer) {
[destinationLayer setContents:(id)img.CGImage];
}
}
The most important lines are
UIGraphicsBeginImageContext(sizeBack);
UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
This is a simple issue, which is bugging me ...
So, I have an object of UIImageView over which, I use
-(void)rotate {
// ...
CGAffineTransform transform = CGAffineTransformMakeRotation(DEGREES_TO_RADIANS(180));
self.image.transform = transform; // image is a property.
}
So, when I call this method once, it rotates the object !. When I call the method again, I expect the object to be rotated again - but it is not rotating by another 180 degrees. After messing with the coordinates and moving the image, I can understand that the -perspective of the object has also be rotated by 180 degrees and all coordinates have been inverted as well.
I want the object's perspective to be restored (although it's been rotated by some angle) such that, I can continue to rotate and move it just like before !
Any ideas ?
Anyways, this code works:
UIImage* rotateUIImage(const UIImage* src, float angleDegrees) {
UIView* rotatedViewBox = [[UIView alloc] initWithFrame: CGRectMake(0, 0, src.size.width, src.size.height)];
float angleRadians = angleDegrees * ((float)M_PI / 180.0f);
CGAffineTransform t = CGAffineTransformMakeRotation(angleRadians);
rotatedViewBox.transform = t;
CGSize rotatedSize = rotatedViewBox.frame.size;
UIGraphicsBeginImageContext(rotatedSize);
CGContextRef bitmap = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(bitmap, rotatedSize.width/2, rotatedSize.height/2);
CGContextRotateCTM(bitmap, angleRadians);
CGContextScaleCTM(bitmap, 1.0, -1.0);
CGContextDrawImage(bitmap, CGRectMake(-src.size.width / 2, -src.size.height / 2, src.size.width, src.size.height), [src CGImage]);
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
Solved the problem with CABasicAnimation !
I want to rotate an UIImage (not UIImageView) in custom degree
I followed this post but it didn't work for me.
Anyone can help? Thanks.
UPDATE:
The code below does some of the job, but I lose some of the image after rotating it:
What should I change to get it right? (btw the yellow color in the screenshots is my UIImageView bg)
- (UIImage *) rotate: (UIImage *) image
{
double angle = 20;
CGSize s = {image.size.width, image.size.height};
UIGraphicsBeginImageContext(s);
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(ctx, 0,image.size.height);
CGContextScaleCTM(ctx, 1.0, -1.0);
CGContextRotateCTM(ctx, 2*M_PI*angle/360);
CGContextDrawImage(ctx,CGRectMake(0,0,image.size.width, image.size.height),image.CGImage);
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
This method return you image on your angle of rotate
#pragma mark -
#pragma mark Rotate Image
- (UIImage *)scaleAndRotateImage:(UIImage *)image {
CGImageRef imgRef = image.CGImage;
CGFloat width = CGImageGetWidth(imgRef);
CGFloat height = CGImageGetHeight(imgRef);
CGAffineTransform transform = CGAffineTransformIdentity;
CGRect bounds = CGRectMake(0, 0, width, height);
CGFloat boundHeight;
boundHeight = bounds.size.height;
bounds.size.height = bounds.size.width;
bounds.size.width = boundHeight;
transform = CGAffineTransformMakeScale(-1.0, 1.0);
transform = CGAffineTransformRotate(transform, M_PI / 2.0); //use angle/360 *MPI
UIGraphicsBeginImageContext(bounds.size);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextConcatCTM(context, transform);
CGContextDrawImage(context, CGRectMake(0, 0, width, height), imgRef);
UIImage *imageCopy = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return imageCopy;
}
- (UIImage *)rotate:(UIImage *)image radians:(float)rads
{
float newSide = MAX([image size].width, [image size].height);
CGSize size = CGSizeMake(newSide, newSide);
UIGraphicsBeginImageContext(size);
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(ctx, newSide/2, newSide/2);
CGContextRotateCTM(ctx, rads);
CGContextDrawImage(UIGraphicsGetCurrentContext(),CGRectMake(-[image size].width/2,-[image size].height/2,size.width, size.height),image.CGImage);
//CGContextTranslateCTM(ctx, [image size].width/2, [image size].height/2);
UIImage *i = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return i;
}
this function rotates any image on its center, but the image becomes a square so I would suggest referencing the image center when drawing it after this function.
You need to address two things to make this work.
You are rotating about the bottom corner of the image instead of the centre
The bounding rectangle of the resulting image needs to be larger now the image is rotated for it to fit in.
To solve the rotation about the centre, first perform a translate to the centre, then rotate, then translate back.
CGAffineTransform transform = CGAffineTransformIdentity;
transform = CGAffineTransformTranslate(transform, boundingRect.size.width/2, boundingRect.size.height/2);
transform = CGAffineTransformRotate(transform, angle);
transform = CGAffineTransformScale(transform, 1.0, -1.0);
CGContextConcatCTM(context, transform);
// Draw the image into the context
CGContextDrawImage(context, CGRectMake(-imageView.image.size.width/2, -imageView.image.size.height/2, imageView.image.size.width, imageView.image.size.height), imageView.image.CGImage);
// Get an image from the context
rotatedImage = [UIImage imageWithCGImage: CGBitmapContextCreateImage(context)];
To calculate the size of the bounding rectangle you'd need to fit the new rotated image into use this:
- (CGRect) getBoundingRectAfterRotation: (CGRect) rectangle byAngle: (CGFloat) angleOfRotation {
// Calculate the width and height of the bounding rectangle using basic trig
CGFloat newWidth = rectangle.size.width * fabs(cosf(angleOfRotation)) + rectangle.size.height * fabs(sinf(angleOfRotation));
CGFloat newHeight = rectangle.size.height * fabs(cosf(angleOfRotation)) + rectangle.size.width * fabs(sinf(angleOfRotation));
// Calculate the position of the origin
CGFloat newX = rectangle.origin.x + ((rectangle.size.width - newWidth) / 2);
CGFloat newY = rectangle.origin.y + ((rectangle.size.height - newHeight) / 2);
// Return the rectangle
return CGRectMake(newX, newY, newWidth, newHeight);
}
You can find these techniques in my previous posts and answers here:
Creating a UIImage from a rotated UIImageView
and here:
Saving 2 UIImages
Hope this helps,
Dave
for rotate image.. you can use this IBAction ... for each and every button click, the image will be rotate by 90 degree...
-(IBAction)rotateImageClick:(id)sender{
UIImage *image2=[[UIImage alloc]init];
image2 = [self imageRotatedByDegrees:self.roateImageView.image deg:(90)]; //Angle by 90 degree
self.roateImageView.image = image2;
imgData= UIImageJPEGRepresentation(image2,0.9f);
}
for rotating image u only have to pass UIimage and rotating degrees for the following method
- (UIImage *)imageRotatedByDegrees:(UIImage*)oldImage deg:(CGFloat)degrees
//------------------------------------------------------------------------
#pragma mark - imageRotatedByDegrees Method
- (UIImage *)imageRotatedByDegrees:(UIImage*)oldImage deg:(CGFloat)degrees{
// calculate the size of the rotated view's containing box for our drawing space
UIView *rotatedViewBox = [[UIView alloc] initWithFrame:CGRectMake(0,0,oldImage.size.width, oldImage.size.height)];
CGAffineTransform t = CGAffineTransformMakeRotation(degrees * M_PI / 180);
rotatedViewBox.transform = t;
CGSize rotatedSize = rotatedViewBox.frame.size;
// Create the bitmap context
UIGraphicsBeginImageContext(rotatedSize);
CGContextRef bitmap = UIGraphicsGetCurrentContext();
// Move the origin to the middle of the image so we will rotate and scale around the center.
CGContextTranslateCTM(bitmap, rotatedSize.width/2, rotatedSize.height/2);
// // Rotate the image context
CGContextRotateCTM(bitmap, (degrees * M_PI / 180));
// Now, draw the rotated/scaled image into the context
CGContextScaleCTM(bitmap, 1.0, -1.0);
CGContextDrawImage(bitmap, CGRectMake(-oldImage.size.width / 2, -oldImage.size.height / 2, oldImage.size.width, oldImage.size.height), [oldImage CGImage]);
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
I think this link will be help.......! Rotate Original Image by clicking button in Objective C
http://adrianmobileapplication.blogspot.com/2015/03/rotate-original-image-by-clicking.html
You have to do some thing like this
YourContainer.transform = CGAffineTransformMakeRotation( 270.0/180*M_PI );
I think rest of the thing you can figured out..