Herer is my resize routine...
in the line CGContextDrawImage the app crashes after 2 or 3 calls of the routine.
there is no memory warning or something.
it just chrashes
- (UIImage *)resizedImage:(CGSize)newSize
transform:(CGAffineTransform)transform
drawTransposed:(BOOL)transpose
interpolationQuality:(CGInterpolationQuality)quality {
CGRect newRect = CGRectIntegral(CGRectMake(0, 0, newSize.width, newSize.height));
CGRect transposedRect = CGRectMake(0, 0, newRect.size.height, newRect.size.width);
CGImageRef imageRef = self.CGImage;
// Build a context that's the same dimensions as the new size
CGContextRef bitmap = CGBitmapContextCreate(NULL,
newRect.size.width,
newRect.size.height,
CGImageGetBitsPerComponent(imageRef),
0,
CGImageGetColorSpace(imageRef),
CGImageGetBitmapInfo(imageRef));
// Rotate and/or flip the image if required by its orientation
CGContextConcatCTM(bitmap, transform);
// Set the quality level to use when rescaling
CGContextSetInterpolationQuality(bitmap, quality);
// Draw into the context; this scales the image
////////////AFTER THAT IT CRASHS!!!
CGContextDrawImage(bitmap, transpose ? transposedRect : newRect, imageRef);
// Get the resized image from the context and a UIImage
CGImageRef newImageRef = CGBitmapContextCreateImage(bitmap);
UIImage *newImage = [UIImage imageWithCGImage:newImageRef];
// Clean up
CGContextRelease(bitmap);
CGImageRelease(newImageRef);
return newImage;
}
someone a hint?
regards, phil
Maybe you should add autorelease pool or #autorelease{} for ARC?
I think, it would help.
Related
When you use .imageView.adjustsImageWhenAncestorFocused you get your image scaled, you get it bigger on focus. The image goes beyond it's bounds. That means that you can't see full image - it's coped on all sides.
You have:
You want:
If you want it work from the box, you need to remember to reserve Focused/Safe zone size (from documentation) when you create your image.
In my case I have my images from server and I can't edit them.
What worked for me - it's to redraw image right before setting:
UIImage *oldImage = [UIImage imageNamed:#"example"];
CGFloat width = cell.imageView.frame.size.width;
CGFloat height = cell.imageView.frame.size.height;
CGSize newSize = CGSizeMake(width, height);
CGRect newRect = CGRectIntegral(CGRectMake(0, 0, newSize.width, newSize.height));
CGImageRef imageRef = oldImage.CGImage;
UIGraphicsBeginImageContextWithOptions(newSize, NO, 0);
CGContextRef resizeContext = UIGraphicsGetCurrentContext();
CGContextSetInterpolationQuality(resizeContext, kCGInterpolationHigh);
CGAffineTransform flipVertical = CGAffineTransformMake(1, 0, 0, -1, 0, newSize.height);
CGContextConcatCTM(resizeContext, flipVertical);
CGContextDrawImage(resizeContext, newRect, imageRef);
CGImageRef newImageRef = CGBitmapContextCreateImage(resizeContext);
UIImage *newImageResized = [UIImage imageWithCGImage:newImageRef];
CGImageRelease(newImageRef);
UIGraphicsEndImageContext();
dispatch_async(dispatch_get_main_queue(), ^{
cell.imageView.image = newImageResized;
});
It's nor necessary to redraw in this way, but the point is you need to draw your UIImage again in order to have your image displayed properly.
Code from here.
I want to add a transparent overlay to an image
The code I am using it :
- (UIImage *) overlayImage
{
VampirizerAppDelegate* app = (VampirizerAppDelegate *)[UIApplication sharedApplication].delegate;
UIImage* pSourceImage;
pSourceImage = pTempResult;
UIImage *topOverlayImg = [UIImage imageNamed:#"overlay-disco-lights-top.png"];
// size is taken from the background image
UIGraphicsBeginImageContext(pSourceImage.size);
[pSourceImage drawAtPoint:CGPointZero];
CGRect topImageRect = CGRectMake(0, 0, pSourceImage.size.width, pSourceImage.size.height);
[pSourceImage drawInRect:topImageRect blendMode:kCGBlendModeOverlay alpha:0.99];
NSLog(#"topImageRect : %#", NSStringFromCGRect(topImageRect));
UIImage *combinedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return combinedImage;
}
the problem is that the final image I am getting is not clear and is distorted.
Please help
I found this great subclass of NSWindow, however it does not add any noise to the gradient of the toolbar. If you look closely at The App Store, Reeder or Twitter they all have noise over the gradient.
How do I add noise to a gradient?
I found this thread but I don't understand how to put this into code.
First of all the nessesary code has been added to INAppStoreWindow, so i have no use case for this anymore. However for people who would like to know how to do this, heres how it's done by INAppStoreWindow.
First a function for making the image with noise is created.
static CGImageRef createNoiseImageRef(NSUInteger width, NSUInteger height, CGFloat factor)
{
NSUInteger size = width*height;
char *rgba = (char *)malloc(size); srand(124);
for(NSUInteger i=0; i < size; ++i){rgba[i] = rand()%256*factor;}
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceGray();
CGContextRef bitmapContext =
CGBitmapContextCreate(rgba, width, height, 8, width, colorSpace, kCGImageAlphaNone);
CFRelease(colorSpace);
free(rgba);
CGImageRef image = CGBitmapContextCreateImage(bitmapContext);
CFRelease(bitmapContext);
return image;
}
Then the image is used to overlay the noise over the current graphics
static CGImageRef noisePattern = nil;
if (noisePattern == nil) noisePattern = createNoiseImageRef(128, 128, 0.015);
[NSGraphicsContext saveGraphicsState];
[[NSGraphicsContext currentContext] setCompositingOperation:NSCompositePlusLighter];
CGRect noisePatternRect = CGRectZero;
noisePatternRect.size = CGSizeMake(CGImageGetWidth(noisePattern), CGImageGetHeight(noisePattern));
CGContextRef context = [[NSGraphicsContext currentContext] graphicsPort];
CGContextDrawTiledImage(context, noisePatternRect, noisePattern);
[NSGraphicsContext restoreGraphicsState];
I am trying to draw an image using core graphics such that it has rounded corners and a drop shadow. Here is a snippet of my code:
CGContextSetShadowWithColor(context, CGSizeMake(0, 1), 2, shadowColor);
CGContextAddPath(context, path);
CGContextClip(context);
CGContextDrawImage(context, rect, image);
The problem I am having is that the clipping to create the rounded corners is also clipping the shadow. Since the image may be transparent in areas, I cannot simply draw the rounded rectangle with a shadow under the image. I guess I need to apply the rounded shape to the image first, and then draw the resulting image to the screen and add the shadow. Does anyone know how to do this?
Thanks!
Okay, so assuming that you have a UIView subclass, which has an instance variable, image, which is a UIImage, then you can do your drawRect: function like so...
- (void)drawRect:(CGRect)rect {
[super drawRect:rect];
CGRect _bounds = [self bounds];
CGColorRef aColor;
CGContextRef context = UIGraphicsGetCurrentContext();
// Create a path
CGRect insetRect = CGRectInset(_bounds, kBSImageButtonBorder, kBSImageButtonBorder);
CGRect offsetRect = insetRect; offsetRect.origin = CGPointZero;
UIGraphicsBeginImageContext(insetRect.size);
CGContextRef imgContext = UIGraphicsGetCurrentContext();
CGPathRef clippingPath = [UIBezierPath bezierPathWithRoundedRect:offsetRect cornerRadius:CORNER_RADIUS].CGPath;
CGContextAddPath(imgContext, clippingPath);
CGContextClip(imgContext);
// Draw the image
[image drawInRect:offsetRect];
// Get the image
UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
// Setup the shadow
aColor = [UIColor colorWithRed:0.0f green:0.0f blue:0.0f alpha:0.5f].CGColor;
CGContextSetShadowWithColor(context, CGSizeMake(0.0f, 2.0f), 2.0f, aColor);
// Draw the clipped image in the context
[img drawInRect:insetRect];
}
I'm a little new to Quartz programming myself, but that should give you your image, centered in the rectangle, minus a border, with a corner radius, and a 2.f point shadow 2.f points below it. Hope that helps.
Here is a function to round the corners of an image using Daniel Thorpe's answer, in case you came here, like me, just looking for a way to do this.
+ (UIImage *) roundCornersOfImage:(UIImage *)image toRadius:(float)radius {
// create image sized context
UIGraphicsBeginImageContext(image.size);
CGContextRef context = UIGraphicsGetCurrentContext();
// add rounded rect clipping path to context using radius
CGRect imageBounds = CGRectMake(0, 0, image.size.width, image.size.height);
CGPathRef clippingPath = [UIBezierPath bezierPathWithRoundedRect:imageBounds cornerRadius:radius].CGPath;
CGContextAddPath(context, clippingPath);
CGContextClip(context);
// draw the image
[image drawInRect:imageBounds];
// get the image
UIImage *outImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return outImage;
}
You can use an imageView with a layer, the layer has properties for setting shadows and borders, this is how:
self.imageView = [[NSImageView alloc] initWithFrame:NSMakeRect(0,0,60,60)];
self.imageView.image = [NSImage imageNamed:#"yourImageName"];
self.imageView.wantsLayer = YES;
self.imageView.layer.cornerRadius = 10;
//make the shadow and set it
NSShadow* shadow = [[NSShadow alloc] init];
shadow.shadowBlurRadius = 2;
shadow.shadowOffset = NSMakeSize(2, -2);
shadow.shadowColor = [NSColor blackColor];
self.imageView.shadow = shadow;
Hope this helps, this is also much faster to draw then using drawRect overrides
I'm making an app in which the user chooses an image, resize it by zooming (in a uiscrollview) and move it in the view. When finished, I would like to save the image like we can see it in the uiscrollview. Do you have any idea ?
Thanks.
Here is the code ......
Here frontGround is a imageview and
testScrool is scroll view
hope this will work for you.
UIGraphicsBeginImageContext(testScrool.frame.size);
CGContextRef currentContext = UIGraphicsGetCurrentContext();
CGRect clippedRect = CGRectMake(0, 0, testScrool.frame.size.width, testScrool.frame.size.height);
CGContextClipToRect(currentContext, clippedRect);
CGRect drawRect = CGRectMake(testScrool.frame.origin.x * -1,
testScrool.frame.origin.y * -1,frontGround.frame.size.width, frontGround.frame.size.height);
CGContextDrawImage(currentContext, drawRect, frontGround.image.CGImage);
UIImage *cropped = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
frontGround.image = cropped;