Android camera preview capture/resizing captured image to match preview -


i trying create , application requires me take captured image , place on current camera preview 0.5 alpha. "overlay" image serves guide capturing next picture; client use overlay compare current frame in preview captured image. simple way approach retrieve last file captured , set view. however, captured image not match camera previews resolution , aspect ratio, causing overlay , preview mismatch in representation of objects (the same object can vary in size between preview , captured image). have tried:

  • using camera preview callbacks store current frame data, inefficient , doesnt work (also has slight translation, dimensions accurate)
  • using aforementioned previous-file method , trying scale down or scale accordingly, match aspect ratio (maybe math wrong [i used aspect ratio of preview calculate area in original image] , still possible use approach? if way in on appreciated).
  • researching ways capture contents of surface view, no avail.

currently, 2 possible methods insight on how approach be:

  • freeze surfaceview somehow (locking canvas of sort), set opacity , use surfaceview display camera (maybe inefficient, clunky workaround?).
  • capture contents of surfaceview , store in bitmap when picturecallback called (preferred).

ofcourse, other suggestions appreciated.

note: there similar questions , i've spent hours going through them none of them correctly address issue or give enough detail.

i got work using 2 textureview components:

  • one set 0.5 alpha , lays on top of other using relativelayout.
  • have opaque textureview register surfacetexturelistener
  • start camera triggered onsurfacetextureavailable in said listener
  • set given surfacetexture previewtexture
  • at button press, draw getbitmap() on canvas of transparent textureview

activity.java (implementing surfacetexturelistener):

@override public void onclick(view view) { {     canvas canvas = alphacameratextureview.lockcanvas();     canvas.drawbitmap( cameratextureview.getbitmap(), 0, 0, null );     alphacameratextureview.unlockcanvasandpost( canvas ); }  @override public void onsurfacetextureavailable( surfacetexture surfacetexture, int width, int height ) {     try     {         camera = camera.open();         camera.setdisplayorientation( 90 );         camera.setpreviewtexture( surfacetexture );         camera.startpreview();     }     catch (ioexception e ) { e.printstacktrace(); } }  @override public boolean onsurfacetexturedestroyed( surfacetexture surfacetexture ) {     camera.stoppreview();     camera.release();     return false; }

textureviews in layout.xml:

<textureview     android:layout_width="match_parent"     android:layout_height="match_parent"     android:id="@+id/cameratextureview"     android:layout_weight="0"/>  <textureview     android:layout_width="match_parent"     android:layout_height="match_parent"     android:id="@+id/alphacameratextureview"     android:alpha="0.5"     android:layout_weight="0" />

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