I need to use openCV to do the image pair in android devices.
For example, I want the mobile devices to match the apple image.
When I open the application, the camera is opening and prepare to detect the apple image. If it is matched, the "match" message will be shown.
Can any one give me some direction to finish it? Thanks.
To match an image, you can using Template Matching or using SURF Detector in Open-CV. see the following links:
http://docs.opencv.org/doc/tutorials/features2d/feature_homography/feature_homography.html
http://docs.opencv.org/doc/tutorials/imgproc/histograms/template_matching/template_matching.html
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I am writing an Android-app that uses the camera. To make it user-friendly, I'd like to display a message when the picture is too dark or the user has his finger in the lens. Is there any possibility to get the camera-state and decide wether it is covered by something or the camera lens is free?
In order to detect whether the camera is covered by some object or not you will have to use OpenCV library and perform the action accordingly after the object is detected. There is nothing inbuilt in android for the task you want to achieve.
Link to OpenCV
You can use the Camera.PreviewCallback coupled with the Camera class to get a callback with a byte array, that byte array contain the image data of that frame.
Then you'll need some sort of algorithm/logic to determine whether or not it's "too dark". There is nothing built into Android that can help you determine that.
I want make an Android app with custom camera API, which can take pictures with some png files as frames(Like some web came apps in PCs). And also first I want to take a picture of ball(or something) which act as frame for the second photo that I am going to take. Anybody have an idea?
Most devices already have a camera application, which you can start for the result if that suits your requirement.
But if you have more extensive requirement android also allows you to directly control the camera. Directly controlling the camera is much more involved and you should access your requirement before deciding on either approach.
You can refere to the following develper guides to get details of both
http://developer.android.com/training/camera/photobasics.html
http://developer.android.com/training/camera/cameradirect.html
Once you get the Bitmap, you can use the canvas element to combine the two bitmaps.
I have gone through all the samples of wikitude. Is it possible to overlay live camera feed image which has been saved as screenshot and create augmenetd image? If it is possible then what tracker image should I use? Because tracker image is the one which I know presently that which image I am going for track. Then if the image will be taken in future how can I create a .wtc file for that and how can I augment my camera feed? Is it possible in wikitude?
I have to create one application using wikitude. I like the sdk of wikitude.
If I understand you correctly you are looking for a way to create target images (that are used for recognition) on the device. This is currently not supported. However if you have a valid business case we are able to provide you with a server based tool to create target images. For more information please contact sales#wikitude.com.
Disclaimer: As you probably already guessed, I'm working for Wikitude.
I have a question regarding where the face detection informaition is stored by Android.
There seem to be two options :
1) The face detection information is stored along with Image as a part of EXIF metadata.
2) Android stores the detected faces information somewhere and retrives when user opens that particular image.
For option 1 I tried to fetch information with Metadata Extractor but there was no tag in particular that corresponds to face detection (correct me if I am wrong)
If it is option 2 how exactly I can filter gallary images according to faces tagged inside ?
Please give me some pointers.
Android have face detection api. You can just call findFaces method for bitmap. Also you cat use external libs and frameworks like OpenCV. According your points - which framefork you use for face detection?
I want to build a mobile app with the following function:
Let user choose an image, then we generate a picture base on that picture.
The generated picture has some specified text with specified font.
There is another picture, which may be a PNG file, used as foreground.
Output that generated picture to user's device.
Is there any way to synthesis image in Android API or using HTML5?
I prefered use some Javascript way to do this, so I can easily build the app cross platform, but I don't know whether JS can do that.
For this purpose you can use HTML5 canvas https://developer.mozilla.org/en/Drawing_Graphics_with_Canvas
If you want to code this using Android API you can use Canvas:
http://developer.android.com/reference/android/graphics/Canvas.html
By the way there is a good guide "Displaying Bitmaps Efficiently" http://developer.android.com/training/displaying-bitmaps/index.html