Crash app while taking picture after edge detection

[dineshsheoran24]

/AndroidRuntime: FATAL EXCEPTION: pool-1-thread-1
Process: com.pengke.paper.scanner, PID: 30656
io.reactivex.exceptions.OnErrorNotImplementedException: Camera is being used after Camera.release() was called
at io.reactivex.internal.functions.Functions$OnErrorMissingConsumer.accept(Functions.java:704)
at io.reactivex.internal.functions.Functions$OnErrorMissingConsumer.accept(Functions.java:701)
at io.reactivex.internal.observers.LambdaObserver.onError(LambdaObserver.java:77)
at io.reactivex.internal.observers.LambdaObserver.onNext(LambdaObserver.java:67)
at io.reactivex.internal.operators.observable.ObservableObserveOn$ObserveOnObserver.drainNormal(ObservableObserveOn.java:200)
at io.reactivex.internal.operators.observable.ObservableObserveOn$ObserveOnObserver.run(ObservableObserveOn.java:252)
at io.reactivex.internal.schedulers.ExecutorScheduler$ExecutorWorker$BooleanRunnable.run(ExecutorScheduler.java:261)
at io.reactivex.internal.schedulers.ExecutorScheduler$ExecutorWorker.run(ExecutorScheduler.java:226)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
at java.lang.Thread.run(Thread.java:764)
Caused by: java.lang.RuntimeException: Camera is being used after Camera.release() was called
at android.hardware.Camera.native_getParameters(Native Method)
at android.hardware.Camera.getParameters(Camera.java:2458)
at com.pengke.paper.scanner.scan.ScanPresenter$onPreviewFrame$1.accept(ScanPresenter.kt:185)
at com.pengke.paper.scanner.scan.ScanPresenter$onPreviewFrame$1.accept(ScanPresenter.kt:36)
at io.reactivex.internal.observers.LambdaObserver.onNext(LambdaObserver.java:63)
at io.reactivex.internal.operators.observable.ObservableObserveOn$ObserveOnObserver.drainNormal(ObservableObserveOn.java:200) 
at io.reactivex.internal.operators.observable.ObservableObserveOn$ObserveOnObserver.run(ObservableObserveOn.java:252) 
at io.reactivex.internal.schedulers.ExecutorScheduler$ExecutorWorker$BooleanRunnable.run(ExecutorScheduler.java:261) 
at io.reactivex.internal.schedulers.ExecutorScheduler$ExecutorWorker.run(ExecutorScheduler.java:226) 
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167) 
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641) 
at java.lang.Thread.run(Thread.java:764)