i am making an android app where the camera preview part is circle so that it will only have to capture the face of the user and beside the circle part make other part black.enter image description here
That would imply making a custom camera yourself instead of using the default one.
Refer to this link for this: https://stackoverflow.com/a/15392209/7528995
You could also use the normal camera instead, since making the user fit their head inside the circled preview would be a bit inconvenient. After capturing the photo you could simply put it into a CircleImageView.
To do this you can refer to this answer: https://stackoverflow.com/a/36613446/7528995
Related
I have an app that rotates other apps. It uses an accessibility service so I have the ability to retrieve screen content.
Say I'm rotating a game called Geometry Dash to the portrait direction. Sometimes it will rotate correctly and look like this:
But other times it incorrectly appears like this:
Is it possible to detect when half the screen is black like in the second pic?
Perhaps using AccessibilityNodeInfo is the key since that class gives information about what's on the screen?
You could do it easily be loading the content of the screen into a bitmap then you can split the bitmap in two parts.
Check if one of them is only black.
I've been following the Camera2 example (android/camera-samples/Camera2Video) to create an abstraction over the Camera2 library. The idea of my abstraction is to give the user the ability to use a Camera view from React Native, so it's just a <Camera> view which can be whatever size/aspect ratio.
While this works out of the box on iOS, I can't seem to get the preview on Android to display "what the camera sees" in the correct aspect ratio.
The official example from Android works like this:
They create a custom SurfaceView extension that should automatically fit to the correct aspect ratio (see: AutoFitSurfaceView)
They use that AutoFitSurfaceView in their layout
They add a listener to the AutoFitSurfaceView's Surface to find out when it has been created (source)
Once the Surface has been created, they call getPreviewOutputSize(...) to get the best matching camera preview size (e.g. so you don't stream 4k for a 1080p screen, that's wasted pixels)
Then they pass the best matching camera preview size to the AutoFitSurfaceView::setAspectRatio(...) function
By knowing the desired aspect ratio, the AutoFitSurfaceView should then automatically perform a center-crop transform in it's onMeasure override
If you read the source code of their getPreviewOutputSize(...) function, you might notice that this uses a Display to find the best matching preview size. If I understood the code correctly, this would only work if the camera preview (AutoFitSurfaceView) is exactly the same size as the device's screen. This is poorly designed, as there are lots of cases where that simply isn't true. In my case, the Camera has a bit of a bottom spacing/margin, so it doesn't fill the screen and therefore has weird resolutions (1080x1585 on a 1080x1920 screen)
With that long introduction, here comes my question: How do I actually perform a correct center crop transform (aka scaleType = CENTER_CROP) on my SurfaceView? I've tried the following:
Set the size of my SurfaceView using SurfaceHolder::setFixedSize(...), but that didn't change anything at all
Remove their getPreviewOutputSize(...) stuff and simply use the highest resolution available
Use the Android View properties scaleX and scaleY to scale the view by the aspect-ratio difference of the view <-> camera input scaler size (this somewhat worked, but is giving me errors if I try to use high-speed capture: Surface size 1080x1585 is not part of the high speed supported size list [1280x720, 1920x1080])
Any help appreciated!
I'd like to "black out" certain locations on a google map in an android app. I'd like to be able to pull location information that would be loaded onto the screen, and just determine whether or not I want to load that segment of the map, or replace it with a black block.
Is this supported by the maps api? Is there any way to make this work?
Take a look at Ground Overlays in Android Maps API. It will let you overlay (or black out) any section of the map based on coordinates.
So if you have a list of locations and their coordinates, you should be able to overlay with a custom image on top of those areas. It has custom options to automatically scale or anchor the image bounds.
I'm attempting to access the raw feed of android's front facing camera. By default, the front facing camera's preview is flipped horizontally so users can see themselves as if looking into a mirror - that's great, but not what I need. What's the best way to get the raw feed? Is there some way to disable the automatic flipping, or should I attempt to flip it in code myself? My application needs to display a real-time feed of the front facing camera without it being flipped like a mirror.
If you want to use a front-facing camera for barcode scanning you can use TextureView and apply a transformation matrix to it. When the texture is updated you can read the image data and use that.
See https://github.com/hadders/camera-reverse
Specifically from MainActivity.java
mCamera.setDisplayOrientation(90);
Matrix matrix = new Matrix();
matrix.setScale(-1, 1);
matrix.postTranslate(width, 0);
mTextureView.setTransform(matrix);
The data from the front camera is as the camera the sees it, looking at you. The left side of its image is your right side. I think this is what you want already? When put onto a SurfaceView it is flipped so it acts as you say, but that's a separate cosmetic transformation.
At least, this is how every device I've seen works and I've looked hard at this to implement front camera support in Barcode Scanner / Barcode Scanner+.
Currently I am developing an application for decoding barcodes using mobile phones.
I have a problem with how to draw a line or a square on the camera screen to easily capture the barcode.
What is the easiest way of doing it?
Unfortunately this isn't as easy as it sounds. If you have a preview image from a phone's camera then it's often rendered as an overlay. This means that the camera preview image doesn't actually form any part of your application's canvas and you can't interact directly with the pixels. The phone simply draws the preview on top of your appliction, completely out of your control.
If you draw a line on your screen, then it will be drawn underneath the preview image.
The way around this isn't too pretty. You need to actually capture an image from the camera. Unfortunately this means capturing a JPEG or a PNG file into a byte buffer. You then load this image using Image.createImage and render that to the screen. You can then safely draw on top of that.
This also has the undesirable downside of giving you an appalling frame-rate. You might want to enumerate all the possible file formats you can capture in and try them all to see which one is quickest.
You can do this by using OverlayControl, assumming that your target devices support it.
I think i remember seeing a good example # Sony Ericsson developer forums.
Edit: found this (does not involve use of OverlayControl)