Here is the code I am using to resize my UIImage, but unfortunately it isn't working:
UIImage *cellImage = [UIImage imageNamed:#"warning.png"];
CGRect cropRect = CGRectMake(0.0, 0.0, 12.0, 12.0);
CGImageRef croppedImage = CGImageCreateWithImageInRect([cellImage CGImage], cropRect);
UIImageView *myImageView = [[UIImageView alloc] initWithFrame:cropRect];
[myImageView setImage:[UIImage imageWithCGImage:croppedImage]];
CGImageRelease(croppedImage);
Why does this code not work?
Thanks
HI try this:-
UIGraphicsBeginImageContext(CGSizeMake(50,50));
[[UIImage imageNamed:#"warning.png"] drawInRect: CGRectMake(0, 0,50,50)];
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
Are you forgetting to add myImageView as a subview of your main view or another visible view? E.g.
[cell.contentView addSubview:myImageView];
This would explain why nothing appears.
However, CGImageCreateWithImageInRect() crops the image within the rect if your rect is smaller than the image. To resize the UIImage itself, see: The simplest way to resize an UIImage?
However, it's easiest if you just let the UIImageView handle the resizing if you don't actually need the UIImage itself resized.
UIImage *cellImage = [UIImage imageNamed:#"warning.png"];
CGRect cropRect = CGRectMake(0.0, 0.0, 12.0, 12.0);
CGImageRef croppedImage = CGImageCreateWithImageInRect([cellImage CGImage], CGRectMake(0.0f,0.0f,cellImage.size.width,cellImage.size.height));
UIImageView *myImageView = [[UIImageView alloc] initWithFrame:cropRect];
[myImageView setImage:[UIImage imageWithCGImage:croppedImage]];
CGImageRelease(croppedImage);
[cell.contentView addSubview:myImageView];
See:
UITableViewCell Class Reference: contentView
I don't know why that doesn't work but try using UIGraphicsBeginImageContext and UIGraphicsEndImageContext instead, UIGraphicsBeginImageContext takes a size.
Related
I have find that for most photos in the gallery, [ALAsset thumbnail] will return the thumbnail with an inward black translucent border.
My question is, how can I obtain the thumbnail without this border?
You have a lot of options. If you just need to display it on screen you could simply fake it so that 1 pixel of the thumbnail isn't visible. You can put a UIImageView inside a UIView that clips to bounds.
UIView* view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 200, 200)];
view.backgroundColor = [UIColor clearColor];
view.clipsToBounds = YES;
UIImageView* imgView = [[UIImageView alloc] initWithFrame:CGRectMake(-1, -1, 202, 202)];
imgView.image = [asset thumbnail];
[view addSubview:imgView];
Or better yet, make a UIView subclass and override drawRect.
-(void)drawRect:(CGRect)rect
{
UIImage* thumb = [asset thumbnail];
[thumb drawInRect:CGRectMake(rect.origin.x-1, rect.origin.y-1, rect.size.width+2, rect.size.height+2)];
}
Or you can use the aspectRatioThumbnail instead and make it squared yourself.
UIImageView* imgView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 200, 200)];
imgView.image = [asset aspectRatioThumbnail];
imgView.contentMode = UIViewContentModeScaleAspectFill;
Or if you actually need to crop the UIImage itself for some reason you can do this.
UIImage* thumb = [asset thumbnail];
CGRect cropRect = CGRectMake(1, 1, thumb.size.width-2, thumb.size.height-2);
cropRect = CGRectMake(cropRect.origin.x*thumb.scale, cropRect.origin.y*thumb.scale, cropRect.size.height*cropRect.scale);
CGImageRef imageRef = CGImageCreateWithImageInRect([thumb CGImage], cropRect);
UIImage* result = [UIImage imageWithCGImage:imageRef scale:thumb.scale orientation:thumb.imageOrientation];
CGImageRelease(imageRef);
There are no methods to get thumbnail without 1 pixel black border.
You can use also
[asset aspectRatioThumbnail]; // but it is not rounded.
So i think you should resize the image yourself using:
asset.defaultRepresentation.fullScreenImage or
asset.defaultRepresentation.fullResolutionImage
I am creating an app that send photo on email,i have created gallery,now i want my app can write text on that photo and send it on email. Any suggestions? tutorials are acceptable.
Simplest but tricky, Add a UIView inside a UIImageView and a UILabel, update with yourimage and text. Now take an UIImage by capture screenshot here. and attach it with your email.
You can create UIImageView with image then place UILabel with clear background on image view, and finally make a UIImage using Core Graphics.
Something like this:
UIImage *bcg = [UIImage imageNamed:#"image.png"];
UIImageView *imgView = [[UIImageView alloc] initWithImage:bcg];
imgView.frame = CGRectZero;//Some frame
[self addSubview:imgView];
[imgView release];
UILabel *text = [[UILabel alloc] initWithFrame:CGRectMake(0, imgView.frame.size.height - 20, imgView.frame.size.width, 20)];
text.backgroundColor = [UIColor clearColor];
text.text = #"Some text";
[imgView addSubview:text];
UIImage *resultImage = nil;
UIGraphicsBeginImageContext(CGSizeMake(self.bounds.size.width,
self.bounds.size.height));
[self.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
CGSize imageSize = CGSizeMake(self.bounds.size.width,
self.bounds.size.height);
UIGraphicsBeginImageContext(imageSize);
[viewImage drawInRect:CGRectMake(0,
0,
imageSize.width,
imageSize.height)
blendMode:kCGBlendModeNormal alpha:1];
resultImage = UIGraphicsGetImageFromCurrentImageContext();
This method easier to debug than draw image and text in context.
I have simple View based application. I had taken only UILabel on it.
Following is my code in viewDidLoad:
lblBack.textColor = [UIColor blueColor];
UIImage *img = [UIImage imageNamed:#"cn3.png"];
lblBack.backgroundColor = [UIColor colorWithPatternImage:img];
lblBack.text = #"Hello World!!!...";
// UIImageView *imgView = [[UIImageView alloc] initWithImage:img];
//
// CGRect rect = CGRectMake(0, 0, lblBack.frame.size.width, lblBack.frame.size.height);
// [imgView setFrame:rect];
// NSLog(#"Rect : %#",NSStringFromCGRect(rect));
// [img drawInRect:rect];
// imgView.contentMode = UIViewContentModeScaleAspectFill;
// imgView.contentMode = UIViewContentModeScaleAspectFit;
// imgView.contentMode = UIViewContentModeScaleToFill;
// [lblBack addSubview:imgView];
Comments shows some of the things that i have tried. I am getting following output:
In this one image is repeated 3 times. But I want that image should be stretched to fill the Label width.
I have referred some of the previous links that shows me to add Image in background and use clearColor for UILabel. Also seen example of Adding custom view in Background. But all this I dont want to use unless I dont have other solutions...
I just want to perform all things on UILabel only.... no other control except UIImage or UIImageView i want to use..
Dhiren try this code :
UIImage *img = [UIImage imageNamed:#"cab.png"];
CGSize imgSize = testLabel.frame.size;
UIGraphicsBeginImageContext( imgSize );
[img drawInRect:CGRectMake(0,0,imgSize.width,imgSize.height)];
UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
testLabel.backgroundColor = [UIColor colorWithPatternImage:newImage];
I have tested this code.
Porting over Maulik's answer to Swift 2.2, you get the following code:
var img: UIImage = UIImage(named: "cabImage")!
var imgSize: CGSize = testLabel.frame.size
UIGraphicsBeginImageContext(imgSize)
img.drawInRect(CGRectMake(0, 0, imgSize.width, imgSize.height))
var newImage: UIImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext();
testLabel.backgroundColor = UIColor(patternImage: newImage)
Personally tested to be working!
I am unable to crop he image from image view, which is scaled and rotated before cropping. used existing cropping methods.but its applicable only for image-view which is fixed.Hope code will helpful.
Finally succeeded cropping rotated scaled image.
1) Need to crop the entire scaled or rotated image.
2)crop the rect from cropped Image. you will get final scaled or rotated cropped image.
Im posting sample code , it may helpful for others.
UIGraphicsBeginImageContextWithOptions(self.view.frame.size, NO, 0.0);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
CGRect rect = CGRectMake(100,100 ,200, 200);//Rect we need from scaled or rotated image.
CGImageRef cropped = CGImageCreateWithImageInRect(viewImage.CGImage, rect);
UIImage *img = [UIImage imageWithCGImage:cropped];
CGImageRelease(cropped);
Thanks.
Try This(if you need to crop the corners):
UIImageView *imageSubview = [[UIImageView alloc] initWithFrame:CGRectMake(50.0f, 5.0f,80.0f, 60.0f)];
[imageSubview setImage:actualImage];
[imageSubview setContentMode:UIViewContentModeScaleToFill];
[imageSubview.layer setCornerRadius:10.0];
[imageSubview.layer setMasksToBounds:YES];
[cell addSubview:imageSubview];
Just increase the radius and you will make it circle, or walk on this path you'll get your actual solution.:)
UIImage *myImage = [UIImage imageNamed:#"photo.png"];
CGRect cropRect = CGRectMake(0.0, 0.0, 320.0, 44.0));
CGImageRef croppedImage = CGImageCreateWithImageInRect([myImage CGImage], cropRect);
UIImageView *myImageView = [[UIImageView alloc] initWithFrame:cropRect];
[myImageView setImage:[UIImage imageWithCGImage:croppedImage]];
CGImageRelease(croppedImage);
its for cropping particular height and width
I'm creating a CALayer like this:
UIColor *color = [UIColor colorWithPatternImage:[UIImage imageNamed:#"MyPattern.png"]];
backgroundLayer = [[CALayer alloc] init];
[backgroundLayer setBackgroundColor:[color CGColor]];
[[self layer] addSublayer:backgroundLayer];
For some reason, the pattern is drawn upside down. I've already tried setting geometryFlipped and applying sublayer transforms, but it doesn't work.
Using [backgroundLayer setTransform:CATransform3DMakeScale(1.0, -1.0, 1.0)]; actually does work.
I would rather use this method:
CALayer *backgroundLayer = [CALayer layer];
backgroundLayer.frame = CGRectMake(50, 50, 200, 200);
UIImage *img = [UIImage imageNamed:#"MyPattern.png"];
CGImageRef imgRef = CGImageRetain(img.CGImage);
backgroundLayer.contents = (id) imgRef;
[self.layer addSublayer:backgroundLayer];
This will provide image content inside the layer and it fits automatically, so it works great for backgrounds. Im not sure why your method isnt working, sorry about that, but I thought it would be nice to provide you with this method.
Instead of using CATransform3DMakeScale you can flip image yourself:
UIImage* img = [UIImage imageNamed:#"MyPattern.png"];
img = [UIImage imageWithCGImage:img.CGImage
scale:img.scale
orientation:UIImageOrientationDownMirrored];
UIColor* color = [UIColor colorWithPatternImage:img];
…
This works fine for me.
Or you can go further and actually redraw the image.
- (UIImage*)flipImage:(UIImage*)image {
UIGraphicsBeginImageContext(image.size);
CGContextDrawImage(UIGraphicsGetCurrentContext(),CGRectMake(0.,0., image.size.width, image.size.height),image.CGImage);
UIImage* img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return img;
}
Details why it can be useful are in this answer.