title: Can Android camera intent specify pictureSize?
body: <p>From my current search, Android camera intent can not specify pictureSize.
  Since my app needs to be fast, I do not want to save a large size picture in sd card, then load it to a small size of Bitmap. I think it takes time. Plus, I need a gray scale image, rather than a color Bitmap. I know how to convert them, but again it takes time. </p>
  
  <p>I plan to take a picture at a specified size, and directly process the Y part (gray scale) in the YUV data in the memory.</p>
  
  <p>So does that mean I have to write my own camera app using camera API?</p>
  
  <p>Are there any good examples?
  Many examples I checked so far often do not consider autofocus.
  I add features in XML file:  </p>
  
  <pre><code>&lt;uses-feature android:name="android.hardware.camera" /&gt;
  &lt;uses-feature android:name="android.hardware.camera.autofocus" /&gt;
  </code></pre>
  
  <p>I add the auto focus mode to the camera parameter.</p>
  
  <pre><code>parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO); 
  </code></pre>
  
  <p>But it does not work.
  So I add autofocus command immediately before camera press button.</p>
  
  <pre><code>preview.camera.autoFocus(myAutoFocusCallback);
  preview.camera.takePicture(shutterCallback, rawCallback, jpegCallback);
  </code></pre>
  
  <p>But the autofocus takes some time, and until the preview becomes clear, the take pictures has been performed.
  Plus, I also want it to autofocus even if I do not press the camera button. 
  How can I put autofocus nicely in it?</p>
  
  <p>Are there any good examples?
  Thanks.</p>