In my iOS app I want to apply a filter CIGaussianBlur on UIImage, when it gets a image having big height it rotates the image
CIContext *context = [CIContext contextWithOptions:nil];
CIImage *inputImage = [[CIImage alloc] initWithImage:image]; //get image for blur
CIFilter *blurFilter = [CIFilter filterWithName:#"CIGaussianBlur"];
[blurFilter setDefaults];
[blurFilter setValue:inputImage forKey:#"inputImage"];
CGFloat blurLevel = 0.0f; // Set blur level
[blurFilter setValue:[NSNumber numberWithFloat:blurLevel] forKey:#"inputRadius"];
// set value for blur level
CIImage *outputImage = [blurFilter valueForKey:#"outputImage"];
CGRect rect = inputImage.extent; // Create Rect
rect.origin.x += blurLevel; // and set custom params
rect.origin.y += blurLevel; //
rect.size.height -= blurLevel*2.0f; //
rect.size.width -= blurLevel*2.0f; //
CGImageRef cgImage = [context createCGImage:outputImage fromRect:rect];
// Then apply new rect
UIImageOrientation originalOrientation = _imageView.image.imageOrientation;
CGFloat originalScale = _imageView.image.scale;
UIImage *fixedImage=[UIImage imageWithCGImage:cgImage scale:originalScale orientation:originalOrientation] ; //output of CIGaussianBlur
It works for me.
_imageView.image=image;
UIImageOrientation originalOrientation = _imageView.image.imageOrientation;
CGFloat originalScale = _imageView.image.scale;
UIImage *fixedImage=[UIImage imageWithCGImage:cgImage scale:originalScale orientation:originalOrientation] ;
Related
I use the following method to generate QR code：
// 1.
CIFilter *filter = [CIFilter filterWithName:#"CIQRCodeGenerator"];
//
[filter setDefaults];
// 2.
NSString *string = #"http://192.168.0.116/1";
NSData *data = [string dataUsingEncoding:NSUTF8StringEncoding];
//
[filter setValue:data forKeyPath:#"inputMessage"];
// 3.
CIImage *image = [filter outputImage];
// 4.
CGFloat scaleX = self.imageView.frame.size.width / image.extent.size.width;
CGFloat scaleY = self.imageView.frame.size.height / image.extent.size.height;
image = [image imageByApplyingTransform:CGAffineTransformMakeScale(scaleX,
scaleY)];
self.imageView.image = [UIImage imageWithCIImage:image scale:[UIScreen
mainScreen].scale orientation:UIImageOrientationUp];`
Got this picture：
But what I want is this denser two-dimensional code image like this:
How do I style it thanks very much
In the past we had two different ways of blurring UIImages, and both led to crashes for our users. The first way crashes when the user puts the device into background (GPU error, not allowed to do anything in background).
The second one crashes with ESC_BAD_ACCESS errors.
What's a better (crash-safe) way to do it?
Version 1:
- (UIImage *)blurred:(float)inputRadius {
// create our blurred image
CIContext *context = [CIContext contextWithOptions:nil];
CIImage *inputImage = [CIImage imageWithCGImage:self.CGImage];
// setting up Gaussian Blur (we could use one of many filters offered by Core Image)
CIFilter *filter = [CIFilter filterWithName:#"CIGaussianBlur"];
[filter setValue:inputImage forKey:kCIInputImageKey];
[filter setValue:[NSNumber numberWithFloat:inputRadius] forKey:#"inputRadius"];
CIImage *result = [filter valueForKey:kCIOutputImageKey];
CGImageRef cgImage = [context createCGImage:result fromRect:[inputImage extent]];
UIImage *blurredImage = [UIImage imageWithCGImage:cgImage];
CFRelease(cgImage);
return blurredImage;
}
Version 2:
- (UIImage*)blurredImage:(CGFloat)blurRadius {
if (blurRadius < 0.0) {
blurRadius = 0.0;
}
CGImageRef img = self.CGImage;
CGFloat inputImageScale = self.scale;
vImage_Buffer inBuffer, outBuffer;
vImage_Error error;
void *pixelBuffer;
CGDataProviderRef inProvider = CGImageGetDataProvider(img);
CFDataRef inBitmapData = CGDataProviderCopyData(inProvider);
inBuffer.width = CGImageGetWidth(img);
inBuffer.height = CGImageGetHeight(img);
inBuffer.rowBytes = CGImageGetBytesPerRow(img);
inBuffer.data = (void*)CFDataGetBytePtr(inBitmapData);
pixelBuffer = malloc(CGImageGetBytesPerRow(img) * CGImageGetHeight(img));
outBuffer.data = pixelBuffer;
outBuffer.width = CGImageGetWidth(img);
outBuffer.height = CGImageGetHeight(img);
outBuffer.rowBytes = CGImageGetBytesPerRow(img);
CGFloat inputRadius = blurRadius * inputImageScale;
if (inputRadius - 2. < __FLT_EPSILON__)
inputRadius = 2.;
uint32_t radius = floor((inputRadius * 3. * sqrt(2 * M_PI) / 4 + 0.5) / 2);
radius |= 1; // force radius to be odd so that the three box-blur methodology works.
// line of crash
error = vImageBoxConvolve_ARGB8888(&inBuffer, &outBuffer, NULL, 0, 0, radius, radius, NULL, kvImageEdgeExtend);
if (!error) {
error = vImageBoxConvolve_ARGB8888(&outBuffer, &inBuffer, NULL, 0, 0, radius, radius, NULL, kvImageEdgeExtend);
}
if (error) {
return self;
}
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef ctx = CGBitmapContextCreate(outBuffer.data,
outBuffer.width,
outBuffer.height,
8,
outBuffer.rowBytes,
colorSpace,
(CGBitmapInfo)kCGImageAlphaNoneSkipLast);
CGImageRef imageRef = CGBitmapContextCreateImage (ctx);
UIImage *returnImage = [UIImage imageWithCGImage:imageRef];
CGContextRelease(ctx);
CGColorSpaceRelease(colorSpace);
free(pixelBuffer);
CFRelease(inBitmapData);
CGImageRelease(imageRef);
return returnImage;
}
My app is crashing when I attempt to apply a filter to my user-selected UIImage (It has been working fine without applying the filter). I added and imported the "CoreImage" framework to my project so I could create filters for user-selected images.
I am attempting to apply the filter by creating a category for UIImage (based on Apple's documentation, and then calling the corresponding method on the UIImage selected by the user. Following is the code of my category header and body; what am I doing wrong? (please note, "randColor" is a category UIColor class method to generate a random color)
#import <UIKit/UIKit.h>
#import <CoreImage/CoreImage.h>
#import "UIColor+CustomColorCategory.h"
#interface UIImage (MonoChromeFilter)
- (UIImage *) applyMonoChromeWithRandColor;
#end
#import "UIImage+MonoChromeFilter.h"
#implementation UIImage (MonoChromeFilter)
- (UIImage *)applyMonoChromeWithRandColor
{
CIContext *context = [CIContext contextWithOptions:nil];
CIImage *ciImage = [[CIImage alloc] initWithImage:self];
CIFilter *filter = [CIFilter filterWithName:#"CIColorMonochrome"];
[filter setValue:ciImage forKey:kCIInputImageKey];
[filter setValue:[UIColor randColor] forKey:kCIAttributeTypeColor];
CIImage *result = [filter valueForKey:kCIOutputImageKey];
CGRect extent = [result extent];
CGImageRef cgImage = [context createCGImage:result fromRect:extent];
UIImage *filteredImage = [[UIImage alloc] initWithCGImage:cgImage];
return filteredImage;
}
#end
Here is the method in the viewController where this category is being called:
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
[picker dismissViewControllerAnimated:YES completion:^{
UIImage *editedImage = [info objectForKey:UIImagePickerControllerEditedImage];
editedImage = [editedImage applyMonoChromeWithRandColor];
self.blogImageOutlet.image = editedImage;
self.blogImageOutlet.layer.cornerRadius = self.blogImageOutlet.frame.size.width / 2.0;
[self.blogImageOutlet setClipsToBounds:YES];
[self saveImageToLibrary:editedImage];
}];
}
I figured it out! After debugging and using some other projects as a point of reference, I realized that I was experiencing two issues. First, I was trying to use a UIColor for CIColor, which is not directly possible. I first had to covert the UIColor to a CIColor to be able to apply it. Next, I was not using the correct strings for the CIFilter value keys. Here is the following code after modifications (and now it works!)
#import "UIImage+MonoChromeFilter.h"
#implementation UIImage (MonoChromeFilter)
+ (UIImage *) applyMonoChromeWithRandColor: (UIImage *)uIImage
{
// Convert UIColor to CIColor
CGColorRef colorRef = [UIColor randColor].CGColor;
NSString *colorString = [CIColor colorWithCGColor:colorRef].stringRepresentation;
CIColor *coreColor = [CIColor colorWithString:colorString];
CIContext *context = [CIContext contextWithOptions:nil];
// Convert UIImage to CIImage
CIImage *ciImage = [[CIImage alloc] initWithImage:uIImage];
// Set values for CIColorMonochrome Filter
CIFilter *filter = [CIFilter filterWithName:#"CIColorMonochrome"];
[filter setValue:ciImage forKey:kCIInputImageKey];
[filter setValue:#1.0 forKey:#"inputIntensity"];
[filter setValue:coreColor forKey:#"inputColor"];
CIImage *result = [filter valueForKey:kCIOutputImageKey];
CGRect extent = [result extent];
CGImageRef cgImage = [context createCGImage:result fromRect:extent];
UIImage *filteredImage = [[UIImage alloc] initWithCGImage:cgImage];
return filteredImage;
}
#end
Try This , It's work like champs for me ,
We have applied different CIFilter for single image,
Below is code for implementation ,
//CISepiaTone Effect,
CIContext *imageContext = [CIContext contextWithOptions:nil];
CIImage *image = [[CIImage alloc]initWithImage:inputimage];
CIFilter *filter = [CIFilter filterWithName:#"CISepiaTone"
keysAndValues: kCIInputImageKey, image,
#"inputIntensity", #1, nil];
CIImage *result = [filter valueForKey: #"outputImage"];
CGImageRef cgImageRef = [imageContext createCGImage:result fromRect:[result extent]];
UIImage *targetImage = [UIImage imageWithCGImage:cgImageRef];
detailsVc.filterImage=targetImage;
[self.navigationController pushViewController:detailsVc animated:YES];
//CIVignette Effect
CIContext *imageContext = [CIContext contextWithOptions:nil];
CIImage *image = [[CIImage alloc] initWithImage:inputimage];
CIFilter *vignette = [CIFilter filterWithName:#"CIVignette"];
[vignette setDefaults];
[vignette setValue: image forKey: #"inputImage"];
[vignette setValue: [NSNumber numberWithFloat: 1.0] forKey: #"inputIntensity"];
[vignette setValue: [NSNumber numberWithFloat: 10.00 ] forKey: #"inputRadius"];
CIImage *result = [vignette valueForKey: #"outputImage"];
CGImageRef cgImageRef = [imageContext createCGImage:result fromRect:[result extent]];
UIImage *targetImage = [UIImage imageWithCGImage:cgImageRef];
detailsVc.filterImage=targetImage;
[self.navigationController pushViewController:detailsVc animated:YES];
For detail implementation you can refer this GitHub project file ImageFilter
Hope so This will help for some one .
I have a UISlider which has a range from 0 to 30.
Unfortunately, when I'm using the UISlider, the image starts to blur, BUT it also rotates.
Here's the code:
-(IBAction)slider:(UISlider *)sender
{
float slideValue = [sender value];
CIImage *beginImage = [[CIImage alloc] initWithImage:image];
CIContext *context = [CIContext contextWithOptions:nil];
CIFilter *filter = [CIFilter filterWithName:#"CIGaussianBlur" keysAndValues:kCIInputImageKey, beginImage, #"inputRadius", [NSNumber numberWithFloat:slideValue], nil];
CIImage *outputImage = [filter valueForKey:kCIOutputImageKey];
CGImageRef cgimg = [context createCGImage:outputImage fromRect:[beginImage extent]];
UIImage *newImg = [UIImage imageWithCGImage:cgimg];
[imageView setImage:newImg];
CGImageRelease(cgimg);
}
Where is the problem?
Thanks in advance.
The problem is this line:
UIImage *newImg = [UIImage imageWithCGImage:cgimg];
This is too simple-minded. Call [UIImage imageWithCGImage:cgimg scale:originalScale orientation:originalOrientation]; (you will need to provide correct values for these).
I'm using the below method to blur some images. Using instruments the CIImage's are leaking. I tried wrapping them in an #autoreleasepool, but no luck. Any ideas?
-(UIImage *)blurImage:(UIImage *)image withStrength:(float)strength
{
#autoreleasepool {
CIContext *context = [CIContext contextWithOptions:nil];
CIImage *inputImage = [[CIImage alloc] initWithCGImage:image.CGImage];
CIFilter *filter = [CIFilter filterWithName:#"CIGaussianBlur"];
[filter setValue:inputImage forKey:#"inputImage"];
[filter setValue:[NSNumber numberWithFloat:strength] forKey:#"inputRadius"];
CIImage *result = [filter valueForKey:kCIOutputImageKey];
float scale = [[UIScreen mainScreen] scale];
CIImage *cropped=[result imageByCroppingToRect:CGRectMake(0, 0, image.size.width*scale, image.size.height*scale)];
CGRect extent = [cropped extent];
CGImageRef cgImage = [context createCGImage:cropped fromRect:extent];
UIImage *returnImage = [UIImage imageWithCGImage:cgImage].copy;
CGImageRelease(cgImage);
return returnImage;
}
}
I see the same leak you're seeing when profiling the code. Try this instead which seems to avoid the leak and give you the same results:
- (UIImage*)blurImage:(UIImage*)image withStrength:(float)strength
{
#autoreleasepool {
CIImage* inputImage = [[CIImage alloc] initWithCGImage:image.CGImage];
CIFilter* filter = [CIFilter filterWithName:#"CIGaussianBlur"];
[filter setValue:inputImage forKey:#"inputImage"];
[filter setValue:[NSNumber numberWithFloat:strength] forKey:#"inputRadius"];
CIImage* result = [filter valueForKey:kCIOutputImageKey];
float scale = [[UIScreen mainScreen] scale];
CIImage* cropped = [result imageByCroppingToRect:CGRectMake(0, 0, image.size.width * scale, image.size.height * scale)];
return [[UIImage alloc] initWithCIImage:cropped];
}
}
did you try to put CIImages to nil ?
-(UIImage *)blurImage:(UIImage *)image withStrength:(float)strength
{
//your code
CGImageRelease(cgImage);
cropped=nil;
result = nil;
inputImage = nil;
context = nil;
return returnImage;
}
}