I am streamlining the AVCamDemo project so that I can experiment with capturing only still images.
Below is the new code for captureStillImage() method:
- (void) captureStillImage
{
AVCaptureConnection *stillImageConnection = [AVCamUtilities connectionWithMediaType:AVMediaTypeVideo fromConnections:[[self stillImageOutput] connections]];
if ([stillImageConnection isVideoOrientationSupported]) {
[stillImageConnection setVideoOrientation:orientation];
}
[[self stillImageOutput] captureStillImageAsynchronouslyFromConnection:stillImageConnection
completionHandler:^(CMSampleBufferRef imageDataSampleBuffer, NSError *error) {
NSLog(#"In the completionHandler block");
if (imageDataSampleBuffer != NULL) {
NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageDataSampleBuffer];
UIImage *image = [[UIImage alloc] initWithData:imageData];
[self writeImageFile:image];
[image release];
}
if ([[self delegate] respondsToSelector:#selector(captureManagerStillImageCaptured:)]) {
[[self delegate] captureManagerStillImageCaptured:self];
}
}];
NSLog(#"exiting....");
}
In my testing, I have found that sometimes, the NSLog statement in the block is not executed....and therefore the stillImage file does not get saved.
Am I running into timing issues? If so, how do I address them?
Thanks, and regards.
Sam.
Related
Im using AVCaptureSession for taking snapshot and save to album. After taking snapshot the image will storing to album. But i need to show the image in camera preview. When i was using UIImagePickerController, after taking picture it displays the preview. But how to do with AVCaptureSession?
code:
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
[self setCaptureSession:[[AVCaptureSession alloc] init]];
[self addVideoInputFrontCamera:NO]; // set to YES for Front Camera, No for Back camera
[self addStillImageOutput];
[self setPreviewLayer:[[AVCaptureVideoPreviewLayer alloc] initWithSession:[self captureSession]] ];
[[self previewLayer] setVideoGravity:AVLayerVideoGravityResizeAspectFill];
CGRect layerRect = [[[self view] layer] bounds];
[[self previewLayer]setBounds:layerRect];
[[self previewLayer] setPosition:CGPointMake(CGRectGetMidX(layerRect),CGRectGetMidY(layerRect))];
[[[self view] layer] addSublayer:[self previewLayer]];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(saveImageToPhotoAlbum) name:kImageCapturedSuccessfully object:nil];
[[self captureSession] startRunning];
}
- (void)addVideoInputFrontCamera:(BOOL)front {
NSArray *devices = [AVCaptureDevice devices];
AVCaptureDevice *frontCamera;
AVCaptureDevice *backCamera;
for (AVCaptureDevice *device in devices) {
NSLog(#"Device name: %#", [device localizedName]);
if ([device hasMediaType:AVMediaTypeVideo]) {
if ([device position] == AVCaptureDevicePositionBack) {
NSLog(#"Device position : back");
backCamera = device;
}
else {
NSLog(#"Device position : front");
frontCamera = device;
}
}
}
NSError *error = nil;
if (front) {
AVCaptureDeviceInput *frontFacingCameraDeviceInput = [AVCaptureDeviceInput deviceInputWithDevice:frontCamera error:&error];
if (!error) {
if ([[self captureSession] canAddInput:frontFacingCameraDeviceInput]) {
[[self captureSession] addInput:frontFacingCameraDeviceInput];
} else {
NSLog(#"Couldn't add front facing video input");
}
}
} else {
AVCaptureDeviceInput *backFacingCameraDeviceInput = [AVCaptureDeviceInput deviceInputWithDevice:backCamera error:&error];
if (!error) {
if ([[self captureSession] canAddInput:backFacingCameraDeviceInput]) {
[[self captureSession] addInput:backFacingCameraDeviceInput];
} else {
NSLog(#"Couldn't add back facing video input");
}
}
}
}
- (void)addStillImageOutput
{
[self setStillImageOutput:[[AVCaptureStillImageOutput alloc] init] ];
NSDictionary *outputSettings = [[NSDictionary alloc] initWithObjectsAndKeys:AVVideoCodecJPEG,AVVideoCodecKey,nil];
[[self stillImageOutput] setOutputSettings:outputSettings];
videoConnection = nil;
for (connection in [[self stillImageOutput] connections]) {
for (AVCaptureInputPort *port in [connection inputPorts]) {
if ([[port mediaType] isEqual:AVMediaTypeVideo] ) {
videoConnection = connection;
break;
}
}
if (videoConnection) {
break;
}
}
[[self captureSession] addOutput:[self stillImageOutput]];
}
- (void)captureStillImageWithOverlay
{
videoConnection = nil;
for (connection in [[self stillImageOutput] connections]) {
for (AVCaptureInputPort *port in [connection inputPorts]) {
if ([[port mediaType] isEqual:AVMediaTypeVideo]) {
videoConnection = connection;
break;
}
}
if (videoConnection) {
break;
}
}
NSLog(#"about to request a capture from: %#", [self stillImageOutput]);
[[self stillImageOutput] captureStillImageAsynchronouslyFromConnection:videoConnection
completionHandler:^(CMSampleBufferRef imageSampleBuffer, NSError *error) {
CFDictionaryRef exifAttachments = CMGetAttachment(imageSampleBuffer, kCGImagePropertyExifDictionary, NULL);
if (exifAttachments) {
NSLog(#"attachements: %#", exifAttachments);
} else {
NSLog(#"no attachments");
}
NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageSampleBuffer];
UIImage *image = [[UIImage alloc] initWithData:imageData];
[self setStillImage:image];
// [image release];
[[NSNotificationCenter defaultCenter] postNotificationName:kImageCapturedSuccessfully object:nil];
}];
}
- (void)saveImageToPhotoAlbum
{
UIImageWriteToSavedPhotosAlbum([self stillImage], self, #selector(image:didFinishSavingWithError:contextInfo:), nil);
}
I want to take picture with overlay image.
code:
- (void)addStillImageOutput
{
// NSLog(#"You capture image");
[self setStillImageOutput:[[[AVCaptureStillImageOutput alloc] init] autorelease]];
NSDictionary *outputSettings = [[NSDictionary alloc] initWithObjectsAndKeys:AVVideoCodecJPEG,AVVideoCodecKey,nil];
[[self stillImageOutput] setOutputSettings:outputSettings];
AVCaptureConnection *videoConnection = nil;
for (AVCaptureConnection *connection in [[self stillImageOutput] connections]) {
for (AVCaptureInputPort *port in [connection inputPorts]) {
if ([[port mediaType] isEqual:AVMediaTypeVideo] ) {
videoConnection = connection;
break;
}
}
if (videoConnection) {
break;
}
}
[[self captureSession] addOutput:[self stillImageOutput]];
}
- (void)captureStillImage
{
AVCaptureConnection *videoConnection = nil;
for (AVCaptureConnection *connection in [[self stillImageOutput] connections]) {
for (AVCaptureInputPort *port in [connection inputPorts]) {
if ([[port mediaType] isEqual:AVMediaTypeVideo]) {
videoConnection = connection;
break;
}
}
if (videoConnection) {
break;
}
}
NSLog(#"about to request a capture from: %#", [self stillImageOutput]);
[[self stillImageOutput] captureStillImageAsynchronouslyFromConnection:videoConnection
completionHandler:^(CMSampleBufferRef imageSampleBuffer, NSError *error) {
CFDictionaryRef exifAttachments = CMGetAttachment(imageSampleBuffer, kCGImagePropertyExifDictionary, NULL);
if (exifAttachments) {
NSLog(#"attachements: %#", exifAttachments);
} else {
NSLog(#"no attachments");
}
NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageSampleBuffer];
UIImage *image = [[UIImage alloc] initWithData:imageData];
[self setStillImage:image];
[image release];
[[NSNotificationCenter defaultCenter] postNotificationName:kImageCapturedSuccessfully object:nil];
}];
}
OverlayImage:
-(void)ButtonPressed1{
UIImageView *overlayImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"sof.png"]];
[overlayImageView setFrame:CGRectMake(30, 100, 260, 200)];
[[self view] addSubview:overlayImageView];
[overlayImageView release];
}
captureStillImageAsynchronouslyFromConnection captures only data from connection (AVCaptureConnection) and the additional images are not in connection. They are in the view.
So, to "generate" an image with all elements (picture and overlay), you must have to do something like this:
UIGraphicsBeginImageContext(stillImage.size);
[stillImage drawInRect:CGRectMake(0, 0, picture.size.width, picture.size.height)];
[overlayImageView drawInRect:CGRectMake(overlayImageView.frame.origin.x, overlayImageView.frame.origin.y, overlayImageView.frame.size.width, overlayImageView.frame.size.height)];
UIImage *result = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
This code is considering that picture size is equal to screen size. If picture size is different, you have to calculate the coordinates to place the overlay in the drawRect method. Sorry for bad english.
I have the following method which retrieves an ALAsset from the UIImagePicker after it snaps a photo. It then attempts to send this ALAsset to another one of my methods via the main thread:
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
NSURL *imageURL = [[info valueForKey:UIImagePickerControllerReferenceURL] retain];
__block ALAsset *result;
[self.assetsLibrary assetForURL:imageURL resultBlock:^(ALAsset *asset)
{
result = [asset retain];
dispatch_async(dispatch_get_main_queue(), ^
{
[self loadPhotoImageViewWithAsset:result];
[self dismissModalViewControllerAnimated:YES];
[imageURL release];
[result release];
});
}
failureBlock:^(NSError *error)
{
}];
}
When I get into the dispatch_async(dispatch_get_main_queue(), ^ block, result is showing as nil. Anyone know what I'm doing wrong here?
Refer UIImagePickerController to use for a UIImageView for result is showing as nil.
Use like this:
[self.assetsLibrary assetForURL:imageURL resultBlock:^(ALAsset *asset)
{
result = [asset retain];
[self loadPhotoImageViewWithAsset:result];
[self dismissModalViewControllerAnimated:YES];
[imageURL release];
[result release];
}
failureBlock:^(NSError *error)
{
}];
Change your loadPhotoImageViewWithAsset Method
-(void)loadPhotoImageViewWithAsset:(ALAsset *)asset
{
//dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0ul);
//dispatch_async(queue, ^{
dispatch_async(dispatch_get_main_queue(), ^
{
//here code for loading image
});
// });
}
I am using somebody's source code for capturing image with AVCaptureSession. However,I found that CaptureSessionManager's previewLayer is shotter then the final captured image.
I found that the resulted image is always with ratio 720x1280=9:16. Now I want to crop the resulted image to an UIImage with ratio 320:480 so that it will only capture the portion visible in previewLayer. Any Idea? Thanks a lot.
Relevant Questions in stackoverflow(NO good answer yet):
Q1,
Q2
Source Code:
- (id)init {
if ((self = [super init])) {
[self setCaptureSession:[[[AVCaptureSession alloc] init] autorelease]];
}
return self;
}
- (void)addVideoPreviewLayer {
[self setPreviewLayer:[[[AVCaptureVideoPreviewLayer alloc] initWithSession:[self captureSession]] autorelease]];
[[self previewLayer] setVideoGravity:AVLayerVideoGravityResizeAspectFill];
}
- (void)addVideoInput {
AVCaptureDevice *videoDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
if (videoDevice) {
NSError *error;
if ([videoDevice isFocusModeSupported:AVCaptureFocusModeContinuousAutoFocus] && [videoDevice lockForConfiguration:&error]) {
[videoDevice setFocusMode:AVCaptureFocusModeContinuousAutoFocus];
[videoDevice unlockForConfiguration];
}
AVCaptureDeviceInput *videoIn = [AVCaptureDeviceInput deviceInputWithDevice:videoDevice error:&error];
if (!error) {
if ([[self captureSession] canAddInput:videoIn])
[[self captureSession] addInput:videoIn];
else
NSLog(#"Couldn't add video input");
}
else
NSLog(#"Couldn't create video input");
}
else
NSLog(#"Couldn't create video capture device");
}
- (void)addStillImageOutput
{
[self setStillImageOutput:[[[AVCaptureStillImageOutput alloc] init] autorelease]];
NSDictionary *outputSettings = [[NSDictionary alloc] initWithObjectsAndKeys:AVVideoCodecJPEG,AVVideoCodecKey,nil];
[[self stillImageOutput] setOutputSettings:outputSettings];
AVCaptureConnection *videoConnection = nil;
for (AVCaptureConnection *connection in [[self stillImageOutput] connections]) {
for (AVCaptureInputPort *port in [connection inputPorts]) {
if ([[port mediaType] isEqual:AVMediaTypeVideo] ) {
videoConnection = connection;
break;
}
}
if (videoConnection) {
break;
}
}
[[self captureSession] addOutput:[self stillImageOutput]];
}
- (void)captureStillImage
{
AVCaptureConnection *videoConnection = nil;
for (AVCaptureConnection *connection in [[self stillImageOutput] connections]) {
for (AVCaptureInputPort *port in [connection inputPorts]) {
if ([[port mediaType] isEqual:AVMediaTypeVideo]) {
videoConnection = connection;
break;
}
}
if (videoConnection) {
break;
}
}
NSLog(#"about to request a capture from: %#", [self stillImageOutput]);
[[self stillImageOutput] captureStillImageAsynchronouslyFromConnection:videoConnection
completionHandler:^(CMSampleBufferRef imageSampleBuffer, NSError *error) {
CFDictionaryRef exifAttachments = CMGetAttachment(imageSampleBuffer, kCGImagePropertyExifDictionary, NULL);
if (exifAttachments) {
NSLog(#"attachements: %#", exifAttachments);
} else {
NSLog(#"no attachments");
}
NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageSampleBuffer];
UIImage *image = [[UIImage alloc] initWithData:imageData];
[self setStillImage:image];
[image release];
[[NSNotificationCenter defaultCenter] postNotificationName:kImageCapturedSuccessfully object:nil];
}];
}
Edit after doing some more research and testing:
AVCaptureSession's property "sessionPreset" has the following constants, I haven't checked each one of them, but noted that most of them ratio is either 9:16, or 3:4,
NSString *const AVCaptureSessionPresetPhoto;
NSString *const AVCaptureSessionPresetHigh;
NSString *const AVCaptureSessionPresetMedium;
NSString *const AVCaptureSessionPresetLow;
NSString *const AVCaptureSessionPreset352x288;
NSString *const AVCaptureSessionPreset640x480;
NSString *const AVCaptureSessionPresetiFrame960x540;
NSString *const AVCaptureSessionPreset1280x720;
NSString *const AVCaptureSessionPresetiFrame1280x720;
In My project, I have the fullscreen preview(frame size is 320x480)
also: [[self previewLayer] setVideoGravity:AVLayerVideoGravityResizeAspectFill];
I have done it in this way: take the photo in size 9:16 and crop it to 320:480, exactly the visible part of the previewlayer. It looks perfect.
The piece of code for resizing and croping to replace with old code is
NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageSampleBuffer];
UIImage *image = [UIImage imageWithData:imageData];
UIImage *scaledimage=[ImageHelper scaleAndRotateImage:image];
//going to crop the image 9:16 to 2:3;with Width fixed
float width=scaledimage.size.width;
float height=scaledimage.size.height;
float top_adjust=(height-width*3/2.0)/2.0;
[self setStillImage:[scaledimage croppedImage:rectToCrop]];
iPhone's camera is natively 4:3. The 16:9 images you get are already cropped from 4:3. Cropping those 16:9 images again to 4:3 is not what you want. Instead get the native 4:3 images from iPhone's camera by setting self.captureSession.sessionPreset = AVCaptureSessionPresetPhoto (before adding any inputs/outputs to the session).
Within my App I'm using a videosession where I can take pictures with. However I'd like to have face detection within this videosession. I looked at Apple's example "SquareCam" which is exactly what I'm looking for. However implementing their code in my project is driving me bonkers.
#import "CaptureSessionManager.h"
#import <ImageIO/ImageIO.h>
#implementation CaptureSessionManager
#synthesize captureSession;
#synthesize previewLayer;
#synthesize stillImageOutput;
#synthesize stillImage;
#pragma mark Capture Session Configuration
- (id)init {
if ((self = [super init])) {
[self setCaptureSession:[[AVCaptureSession alloc] init]];
}
return self;
}
- (void)didReceiveMemoryWarning
{
// Releases the view if it doesn't have a superview.
NSLog(#"memorywarning");
// Release any cached data, images, etc that aren't in use.
}
- (void)addVideoPreviewLayer {
[self setPreviewLayer:[[[AVCaptureVideoPreviewLayer alloc] initWithSession:[self captureSession]] autorelease]];
[[self previewLayer] setVideoGravity:AVLayerVideoGravityResizeAspectFill];
}
- (void)addVideoInput {
AVCaptureDevice *videoDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
if ([videoDevice isFocusModeSupported:AVCaptureFocusModeLocked]) {
NSError *error = nil;
if ([videoDevice lockForConfiguration:&error]) {
NSLog(#"focus");
videoDevice.focusMode = AVCaptureFocusModeLocked;
videoDevice.focusMode = AVCaptureFocusModeContinuousAutoFocus;
//videoDevice.focusMode = AVCaptureSessionPresetPhoto
videoDevice.whiteBalanceMode = AVCaptureWhiteBalanceModeContinuousAutoWhiteBalance;
[captureSession setSessionPreset:AVCaptureSessionPresetPhoto];
[videoDevice unlockForConfiguration];
}
else {
}
}
// Respond to the failure as appropriate.
if (videoDevice) {
NSError *error;
AVCaptureDeviceInput *videoIn = [AVCaptureDeviceInput deviceInputWithDevice:videoDevice error:&error];
if (!error) {
if ([[self captureSession] canAddInput:videoIn])
[[self captureSession] addInput:videoIn];
else
NSLog(#"Couldn't add video input");
}
else
NSLog(#"Couldn't create video input");
}
else
NSLog(#"Couldn't create video capture device");
}
- (void)addStillImageOutput
{
[self setStillImageOutput:[[[AVCaptureStillImageOutput alloc] init] autorelease]];
NSDictionary *outputSettings = [[NSDictionary alloc] initWithObjectsAndKeys:AVVideoCodecJPEG,AVVideoCodecKey,nil];
[[self stillImageOutput] setOutputSettings:outputSettings];
AVCaptureConnection *videoConnection = nil;
for (AVCaptureConnection *connection in [[self stillImageOutput] connections]) {
for (AVCaptureInputPort *port in [connection inputPorts]) {
if ([[port mediaType] isEqual:AVMediaTypeVideo] ) {
videoConnection = connection;
break;
}
}
if (videoConnection) {
break;
}
}
[[self captureSession] addOutput:[self stillImageOutput]];
[outputSettings release];
}
- (void)captureStillImage
{
AVCaptureConnection *videoConnection = nil;
for (AVCaptureConnection *connection in [[self stillImageOutput] connections]) {
for (AVCaptureInputPort *port in [connection inputPorts]) {
if ([[port mediaType] isEqual:AVMediaTypeVideo]) {
videoConnection = connection;
break;
}
}
if (videoConnection) {
break;
}
}
NSLog(#"about to request a capture from: %#", [self stillImageOutput]);
[[self stillImageOutput] captureStillImageAsynchronouslyFromConnection:videoConnection
completionHandler:^(CMSampleBufferRef imageSampleBuffer, NSError *error) {
CFDictionaryRef exifAttachments = CMGetAttachment(imageSampleBuffer, kCGImagePropertyExifDictionary, NULL);
if (exifAttachments) {
NSLog(#"attachements: %#", exifAttachments);
} else {
NSLog(#"no attachments");
}
NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageSampleBuffer];
UIImage *image = [[UIImage alloc] initWithData:imageData];
[self setStillImage:image];
[image release];
[[NSNotificationCenter defaultCenter] postNotificationName:kImageCapturedSuccessfully object:nil];
}];
}
- (void)dealloc {
[[self captureSession] stopRunning];
[previewLayer release], previewLayer = nil;
[captureSession release], captureSession = nil;
[stillImageOutput release], stillImageOutput = nil;
[stillImage release], stillImage = nil;
[super dealloc];
}
#end
Besides my videosession I did succeeded with recognizing faces within a UIImage which I imported inside my project. I did this with the example of #Abhinav Jha (How to properly instantiate CIDetector class object in iOS 5 face detection API).
CIImage *ciImage = [[CIImage alloc] initWithImage:[UIImage imageNamed:#"Photo.JPG"]];
if (ciImage == nil)
[imageView setImage:[UIImage imageNamed:#"Photo.JPG"]];
NSDictionary *options = [[NSDictionary alloc] initWithObjectsAndKeys:
#"CIDetectorAccuracy", #"CIDetectorAccuracyHigh",nil];
CIDetector *ciDetector = [CIDetector detectorOfType:CIDetectorTypeFace
context:nil
options:options];
NSArray *features = [ciDetector featuresInImage:ciImage];
NSLog(#"no of face detected: %d", [features count]);
Hope someone can point me in the right direction with combining the two examples!