I have a photo editing app where I want to provide a way for the user to edit photos from the pasteboard. For example the user might copy a photo from his website in Safari and then head over to my app and choose "Open from pasteboard". Kind of like Photoshop does it.
How can I get notified or check if there is a picture or graphic (probably a UIImage) in the pasteboard? And how could I obtain that image?
I needed one for a UIImage and this snippet helped me out.
You can always extract the image out using:
UIImage *image = [UIPasteboard generalPasteboard].image;
Related
I am working on an Iphone application.
The idea of the application is to allow the user to download a picture and to save it on his phone. and he can later open it. (Normal caching system)
What I am doing now is I get the UIIamge from the server and then I save it on the phone using:
UIImageWriteToSavedPhotosAlbum
And then I use the imagePickerController to allow the user to load the image.
My question is:
Is there a way I can save the image in the application folder? The idea is that I don't want to allow the user to delete the image from outside the application(I have a "clear images" button). Is there a place I can cache the images other than the Photo library? maybe in the application bundle or folder?
Thank you
Use either of the following methods to save the UIImage into your app's document directory
[UIImageJPEGRepresentation(image, JPEG_COMPRESSION_QUALITY)
writeToFile:photoPath atomically:YES];
or
[UIImagePNGRepresentation(image) writeToFile:photoPath atomically:YES];
I'm not quite new but still have a few noob questions this is one of them.
I need a path to one of the pictures all ready in my camera roll on my test iphone. How do I get/find this, not programmatically. I want to hard code it for testing for file upload so I can trouble shoot.
so
filePath:#"/private/var/mobile/Applications/14C39895-E73B-400F-8158-F1F5047A826C/tmp/upload.jpg"
should be what:
filePath:#"fill in this spot"
You can't access the photos directly (unless your app wrote them to the docs folder to begin with -- in which case you would know the path). You'll need to implement a UIImagePicker to select the photo from your photo album. The UIImagePicker delegate will then have access to the photo where you can do whatever you want with it(including writing a copy of it to documents). After the photos been selected once and written to docs, you could then access it in documents on later executions of the app.
The UIImagePicker delegate should implement:
-(void) imagePickerController:(UIImagePickerController *) picker didFinishPickingMediaWithInfo:(NSDictionary *) info {
UIImage *image = [info objectForKey:UIImagePickerControllerOriginalImage];
}
Then you can write the image to your apps docs folder in that delegate method, something like this:
http://blog.objectgraph.com/index.php/2010/04/05/download-an-image-and-save-it-as-png-or-jpeg-in-iphone-sdk/
At that point you could always access the photo in your apps docs folder for upload testing... You probably need to implement a UIImagePicker for your app anyway, so instead of looking for your test photo, it may be easier to just select from photo album using UIImagePicker and upload directly (cutting out the whole writing/reading from docs folder).
Hope that helps!
I'm writing a function to download a regular PNG file from web server and save it to iPhone Photos album. I don't get any error for my code listed below but UIImagePNGRepresentation doesn't perform the convert at all. All images I got were black. I have to enable "auto-enhanced" under Photos to display those image properly. Any clue what's wrong with my code? Thanks in advance.
UIImage *orgImg = [[UIImage alloc] initWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:#"http://server.com/test.png"]]];
NSData * convertedData = UIImagePNGRepresentation(orgImg);
UIImage * img = [UIImage imageWithData: convertedData];
// Save Image to Photo Album
UIImageWriteToSavedPhotosAlbum(img, self,
#selector(thisImage:hasBeenSavedInPhotoAlbumWithError:usingContextInfo:), nil);
Some more details of these two output images, orgImg and img:
If I pass orgImg to UIImageWriteToSavedPhotosAlbum directly, I did get the same PNG image hosted on the server. However Photos application on my iPhone displays it as a black image because Photos doesn't enhance PNG format automatically.
As for the img I got after using UIImagePNGRepresentation, the image data has been changed by the method, some meta data such as width/height have been removed from the original image. However Photos app on my iPhone still display it as an all black image.
Both images display properly if I copy them into either Safari or email. I didn't get any problem if I use JPEG in the server side either. Just curious why only PNG format doesn't work.
I am writing an application which lets the user pick one photograph from a selection. Then I want to save that photograph to their photo roll to a specific name. i.e I always want the photo in the roll to be named the same thing and overwrite previous selections.
UIImage* image = [UIImage imageNamed:[ImageNames objectAtIndex:self.miImage]];
UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil);
I can't find anyway to make a copy of the image and assign a new name to it, or specify a target name for UIImageWriteToSavedPhotosAlbum().
Is there any way to do this?
thanks in advance,
Jay
You cannot specify a filename when using UIImageWriteToSavedPhotosAlbum because it saves the image to the Camera Roll (or the Photos Library, if the device does not have a camera). This allows the system to assign it a name based on a format, like "DSC0001.jpg" or similar, and avoid name collisions.
Because of this, overwriting an image is also not possible, since the Photo Library / Camera Roll are controlled by the user - a user that would not appreciate a photo being overwritten by your application.
...writing the image to the user’s Camera Roll or Saved Photos album.
UIImageWriteToSavedPhotosAlbum Reference
I would like to access an image file in the iPhone images directory.
Then I would like to open this file as binary and be able to rewrite it.
Assuming user has chosen this file using the UIImagePickerController, is it possible to do such thing using iPhone API?
http://developer.apple.com/library/ios/#DOCUMENTATION/AudioVideo/Conceptual/CameraAndPhotoLib_TopicsForIOS/Articles/PickinganItemfromthePhotoLibrary.html this tutorial will help you in getting UIImage from photo library.
Once you obtain the image, you can do custom modifications to the UIImage and save it to photo album using this API:
Adds the specified image to the user’s Camera Roll album.
void UIImageWriteToSavedPhotosAlbum (
UIImage *image,
id completionTarget,
SEL completionSelector,
void *contextInfo
);
If you are looking to replace the existing photo from Photo library , there is no direct (or Apple Approved) way to do that. If you still want to do that, you can find path to photo library (/private/var/mobile/Media/DCIM/100APPLE) and try rewriting the photos.