I am attempting to understand the following code and how you would convert it to Swift. Specifically, I understand this adds an instance method you can call on an instance of CIImage. My question is, how you can do the same thing in a Swift class?
This code is taken from AAPLAssetViewController.m in Apple's example app using the Photos framework.
#implementation CIImage (Convenience)
- (NSData *)aapl_jpegRepresentationWithCompressionQuality:(CGFloat)compressionQuality {
static CIContext *ciContext = nil;
if (!ciContext) {
EAGLContext *eaglContext = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES2];
ciContext = [CIContext contextWithEAGLContext:eaglContext];
}
CGImageRef outputImageRef = [ciContext createCGImage:self fromRect:[self extent]];
UIImage *uiImage = [[UIImage alloc] initWithCGImage:outputImageRef scale:1.0 orientation:UIImageOrientationUp];
if (outputImageRef) {
CGImageRelease(outputImageRef);
}
NSData *jpegRepresentation = UIImageJPEGRepresentation(uiImage, compressionQuality);
return jpegRepresentation;
}
#end
Call it like so:
NSData *jpegData = [myCIImage aapl_jpegRepresentationWithCompressionQuality:0.9f];
From The Swift Programming Language - Extensions:
Extensions add new functionality to an existing class, structure, or enumeration type. (...) Extensions are similar to categories in Objective-C.
https://developer.apple.com/library/ios/documentation/Swift/Conceptual/Swift_Programming_Language/Extensions.html
Related
I'm working with an existing code base that accepts bytes from a loaded jpeg file and creates a UIImage object. That works fine on iphone but macOS needs a different implementation from what I've understood.
UIImage* image = [UIImage imageWithData:[NSData dataWithBytes:data length:length]];
if (image)
{
}
What is the equivalent of this on macOS? is it NsImage? How do I implement this?
Here it is
NSImage* image = [[NSImage alloc] initWithData:[NSData dataWithBytes:data length:length]];
if (image)
{
}
I'm generating a CIImage using a few chained filters and trying to output the generated image in the users photo album for certain debug purposes. The callback I supply to UIImageWriteToSavedPhotosAlbum() always has a nil error returned, so I assume nothing is going wrong. But the image never seems to show up.
I've used this function in the past to dump OpenGL buffers to the photo album for debugging, but I realize this isn't the same case. Should I be doing something differently?
-(void)cropAndSaveImage:(CIImage *)inputImage fromFeature:(CIFaceFeature *)feature
{
// First crop out the face.
[_cropFilter setValue:inputImage forKey:#"inputImage"];
[_cropFilter setValue:[CIVector vectorWithCGRect:feature.bounds] forKey:#"inputRectangle"];
CIImage * croppedImage = _cropFilter.outputImage;
__block CIImage * outImage = croppedImage;
dispatch_async(dispatch_get_main_queue(), ^{
UIImage * outUIImage = [UIImage imageWithCIImage:outImage];
UIImageWriteToSavedPhotosAlbum(outUIImage, self, #selector(image:didFinishSavingWithError:contextInfo:), nil);
});
}
-(void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo
{
NSLog(#"debug LBP output face. error: %#", error);
}
I've verified that the boundaries are never 0.
The callback output is always
debug LBP output face. error: (null)
I figured this out on my own and deleted the question, but then I thought maybe someone will get some use out of it. I say this because I came across an older answer that suggested the original implementation worked. But in actuality in had to do the following to make it work properly.
__block CIImage * outImage = _lbpFilter.outputImage;
dispatch_async(dispatch_get_main_queue(), ^{
CGImageRef imgRef = [self renderCIImage:outImage];
UIImage * uiImage = [UIImage imageWithCGImage:imgRef];
UIImageWriteToSavedPhotosAlbum(uiImage, self, #selector(image:didFinishSavingWithError:contextInfo:), nil);
});
+ (CGImageRef)renderCIImage:(CIImage *)img
{
if ( !m_ctx ) {
NSDictionary * options = #{kCIContextOutputColorSpace:[NSNull null], kCIContextWorkingColorSpace:[NSNull null]};
m_ctx = [CIContext contextWithOptions:options];
}
return [m_ctx createCGImage:img fromRect:img.extent];
}
Using filter.outputImage to convert to CGImage by CIContext.createCGImage() and converting CGImage to UIImage will save image successfully.
I'm getting a UIImage from a CMSampleBufferRef video buffer every N video frames like:
- (void)imageFromVideoBuffer:(void(^)(UIImage* image))completion {
CMSampleBufferRef sampleBuffer = _myLastSampleBuffer;
if (sampleBuffer != nil) {
CFRetain(sampleBuffer);
CIImage *ciImage = [CIImage imageWithCVPixelBuffer:CMSampleBufferGetImageBuffer(sampleBuffer)];
_lastAppendedVideoBuffer.sampleBuffer = nil;
if (_context == nil) {
_context = [CIContext contextWithOptions:nil];
}
CVPixelBufferRef buffer = CMSampleBufferGetImageBuffer(sampleBuffer);
CGImageRef cgImage = [_context createCGImage:ciImage fromRect:
CGRectMake(0, 0, CVPixelBufferGetWidth(buffer), CVPixelBufferGetHeight(buffer))];
__block UIImage *image = [UIImage imageWithCGImage:cgImage];
CGImageRelease(cgImage);
CFRelease(sampleBuffer);
if(completion) completion(image);
return;
}
if(completion) completion(nil);
}
XCode and Instruments detect a Memory Leak, but I'm not able to get rid of it.
I'm releasing the CGImageRef and CMSampleBufferRef as usual:
CGImageRelease(cgImage);
CFRelease(sampleBuffer);
[UPDATE]
I put in the AVCapture output callback to get the sampleBuffer.
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection {
if (captureOutput == _videoOutput) {
_lastVideoBuffer.sampleBuffer = sampleBuffer;
id<CIImageRenderer> imageRenderer = _CIImageRenderer;
dispatch_async(dispatch_get_main_queue(), ^{
#autoreleasepool {
CIImage *ciImage = nil;
ciImage = [CIImage imageWithCVPixelBuffer:CMSampleBufferGetImageBuffer(sampleBuffer)];
if(_context==nil) {
_context = [CIContext contextWithOptions:nil];
}
CGImageRef processedCGImage = [_context createCGImage:ciImage
fromRect:[ciImage extent]];
//UIImage *image=[UIImage imageWithCGImage:processedCGImage];
CGImageRelease(processedCGImage);
NSLog(#"Captured image %#", ciImage);
}
});
The code that leaks is the createCGImage:ciImage:
CGImageRef processedCGImage = [_context createCGImage:ciImage
fromRect:[ciImage extent]];
even having a autoreleasepool, the CGImageRelease of the CGImage reference and a CIContext as instance property.
This seems to be the same issue addressed here: Can't save CIImage to file on iOS without memory leaks
[UPDATE]
The leak seems to be due a bug. The issue is well described in
Memory leak on CIContext createCGImage at iOS 9?
A sample project shows how to reproduce this leak: http://www.osamu.co.jp/DataArea/VideoCameraTest.zip
The last comments assure that
It looks like they fixed this in 9.1b3. If anyone needs a workaround
that works on iOS 9.0.x, I was able to get it working with this:
in a test code (Swift in this case):
[self.stillImageOutput captureStillImageAsynchronouslyFromConnection:videoConnection completionHandler: ^(CMSampleBufferRef imageSampleBuffer, NSError *error)
{
if (error) return;
__block NSString *filePath = [NSTemporaryDirectory() stringByAppendingPathComponent:[NSString stringWithFormat:#"ipdf_pic_%i.jpeg",(int)[NSDate date].timeIntervalSince1970]];
NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageSampleBuffer];
dispatch_async(dispatch_get_main_queue(), ^
{
#autoreleasepool
{
CIImage *enhancedImage = [CIImage imageWithData:imageData];
if (!enhancedImage) return;
static CIContext *ctx = nil; if (!ctx) ctx = [CIContext contextWithOptions:nil];
CGImageRef imageRef = [ctx createCGImage:enhancedImage fromRect:enhancedImage.extent format:kCIFormatBGRA8 colorSpace:nil];
UIImage *image = [UIImage imageWithCGImage:imageRef scale:1.0 orientation:UIImageOrientationRight];
[[NSFileManager defaultManager] createFileAtPath:filePath contents:UIImageJPEGRepresentation(image, 0.8) attributes:nil];
CGImageRelease(imageRef);
}
});
}];
and the workaround for iOS9.0 should be
extension CIContext {
func createCGImage_(image:CIImage, fromRect:CGRect) -> CGImage {
let width = Int(fromRect.width)
let height = Int(fromRect.height)
let rawData = UnsafeMutablePointer<UInt8>.alloc(width * height * 4)
render(image, toBitmap: rawData, rowBytes: width * 4, bounds: fromRect, format: kCIFormatRGBA8, colorSpace: CGColorSpaceCreateDeviceRGB())
let dataProvider = CGDataProviderCreateWithData(nil, rawData, height * width * 4) {info, data, size in UnsafeMutablePointer<UInt8>(data).dealloc(size)}
return CGImageCreate(width, height, 8, 32, width * 4, CGColorSpaceCreateDeviceRGB(), CGBitmapInfo(rawValue: CGImageAlphaInfo.PremultipliedLast.rawValue), dataProvider, nil, false, .RenderingIntentDefault)!
}
}
We were experiencing a similar issue in an app we created, where we are processing each frame for feature keypoints with OpenCV, and sending off a frame every couple of seconds. After a while of running we would end up with quite a few memory pressure messages.
We managed to rectify this by running our processing code in it's own auto release pool like so (jpegDataFromSampleBufferAndCrop does something similar to what you are doing, with added cropping):
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection
{
#autoreleasepool {
if ([self.lastFrameSentAt timeIntervalSinceNow] < -kContinuousRateInSeconds) {
NSData *imageData = [self jpegDataFromSampleBufferAndCrop:sampleBuffer];
if (imageData) {
[self processImageData:imageData];
}
self.lastFrameSentAt = [NSDate date];
imageData = nil;
}
}
}
}
I can confirm that this memory leak still exists on iOS 9.2. (I've also posted on the Apple Developer Forum.)
I get the same memory leak on iOS 9.2. I've tested dropping EAGLContext by using MetalKit and MLKDevice. I've tested using different methods of CIContext like drawImage, createCGImage and render but nothing seem to work.
It is very clear that this is a bug as of iOS 9. Try it out your self by downloading the example app from Apple (see below) and then run the same project on a device with iOS 8.4, then on a device with iOS 9.2 and pay attention to the memory gauge in Xcode.
Download https://developer.apple.com/library/ios/samplecode/AVBasicVideoOutput/Introduction/Intro.html#//apple_ref/doc/uid/DTS40013109
Add this to the APLEAGLView.h:20
#property (strong, nonatomic) CIContext* ciContext;
Replace APLEAGLView.m:118 with this
[EAGLContext setCurrentContext:_context];
_ciContext = [CIContext contextWithEAGLContext:_context];
And finaly replace APLEAGLView.m:341-343 with this
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
#autoreleasepool
{
CIImage* sourceImage = [CIImage imageWithCVPixelBuffer:pixelBuffer];
CIFilter* filter = [CIFilter filterWithName:#"CIGaussianBlur" keysAndValues:kCIInputImageKey, sourceImage, nil];
CIImage* filteredImage = filter.outputImage;
[_ciContext render:filteredImage toCVPixelBuffer:pixelBuffer];
}
glBindRenderbuffer(GL_RENDERBUFFER, _colorBufferHandle);
I have a big memory leak that I have pinpointed to happen in/on requestContentEditingInputWithOptions: method. If I understand it right it happens with the img variable. If I make it __block __weak the image is nil already after I assign it (img = [UIImage...]). Am I being silly somewhere? Or how would I avoid this memory leak?
- (UIImage*) getRightlySizedImgFromAsset:(PHAsset*)asset {
__block UIImage *img;
PHContentEditingInputRequestOptions *coptions = [PHContentEditingInputRequestOptions new];
coptions.canHandleAdjustmentData = ^BOOL(PHAdjustmentData *adjustmentData) { return NO; };
//semaphore used so the block runs synchronously and I can return img from this method at the end
dispatch_semaphore_t sem = dispatch_semaphore_create(0);
[asset requestContentEditingInputWithOptions:coptions completionHandler:^(PHContentEditingInput *contentEditingInput, NSDictionary *info) {
NSURL* url = [contentEditingInput fullSizeImageURL];
int orientation = [contentEditingInput fullSizeImageOrientation];
CIImage* inputImage = [CIImage imageWithContentsOfURL:url options:nil];
inputImage = [inputImage imageByApplyingOrientation:orientation];
CIContext *context = [CIContext contextWithOptions:nil];
img = [UIImage imageWithCGImage:[context createCGImage:inputImage fromRect:inputImage.extent]];
dispatch_semaphore_signal(sem);
}];
dispatch_semaphore_wait(sem, DISPATCH_TIME_FOREVER);
if (needToDoSomethingWithImg){
[self doSomethingWithImage:img];
}
return img;
}
Run this code through the static analyzer (shift+command+B or choose "Analyze" from the "Product" menu) and it will point out that createCGImage is creating a CGImageRef that you're never releasing.
You might want to do something like:
CGImageRef imageRef = [context createCGImage:inputImage fromRect:inputImage.extent];
img = [UIImage imageWithCGImage:imageRef];
CFRelease(imageRef);
By the way, you should not do this synchronously. You should do something like:
- (void) getRightlySizedImgFromAsset:(PHAsset*)asset completionHandler:(void (^)(UIImage *))completionHandler {
PHContentEditingInputRequestOptions *coptions = [PHContentEditingInputRequestOptions new];
coptions.canHandleAdjustmentData = ^BOOL(PHAdjustmentData *adjustmentData) { return NO; };
[asset requestContentEditingInputWithOptions:coptions completionHandler:^(PHContentEditingInput *contentEditingInput, NSDictionary *info) {
NSURL* url = [contentEditingInput fullSizeImageURL];
int orientation = [contentEditingInput fullSizeImageOrientation];
CIImage* inputImage = [CIImage imageWithContentsOfURL:url options:nil];
inputImage = [inputImage imageByApplyingOrientation:orientation];
CIContext *context = [CIContext contextWithOptions:nil];
CGImageRef imageRef = [context createCGImage:inputImage fromRect:inputImage.extent];
UIImage *image = [UIImage imageWithCGImage:imageRef];
CFRelease(imageRef);
// if this stuff needs to happen on main thread, then dispatch it to the main thread
if (needtodosomethingwithit)
[self doSomethingWithImage:image];
if (completionHandler) {
completionHandler(image);
}
}];
}
Rob is right on the money. And images can be big, so that's why you have a big leak. The rule of thumb with Core Foundation objects is the "create rule." Search in Xcode on "Create Rule" and read the article. The gist of it is this:
Core Foundation functions have names that indicate when you own a
returned object:
Object-creation functions that have “Create” embedded in the name;
Object-duplication functions that have “Copy” embedded in the name. If
you own an object, it is your responsibility to relinquish ownership
(using CFRelease) when you have finished with it.
I am trying to update a UIImage with geotag information. I looked at Saving Geotag info with photo on iOS4.1, which is where I found a reference to the NSMutableDDictionary+ImageMetadata category. However, I don't want to save to the photo album, but have a UIImage to pass on.
The following code seemed like it was making too many copies of the image and required all these frameworks linked: CoreImage, AssetsLibrary, CoreMedia, ImageIO.
Is there something more efficient that UIImage -> CIImage -> CGImage -> UIImage that can take the properties NSDictionary needed for setting EXIF data?
- (UIImage *)updateImage:(UIImage *)image location:(CLLocation *)location dateOriginal:(NSDate *)dateOriginal
{
NSMutableDictionary *properties = [NSMutableDictionary dictionaryWithDictionary:[image.CIImage properties]];
// uses https://github.com/gpambrozio/GusUtils
[properties setLocation:location];
[properties setDateOriginal:dateOriginal];
CIImage *tempImage = [[CIImage alloc] initWithImage:image options:properties];
CIContext *context = [CIContext contextWithOptions:nil];
UIImage *updatedImage = [UIImage imageWithCGImage:[context createCGImage:tempImage fromRect:tempImage.extent]];
return updatedImage;
}
Have a look at libexif: http://libexif.sourceforge.net/
You'll probably need to pass the image's byte data to the library using
UIImageJPEGRepresentation(image, quality) bytes]