get Optimal Preview Size with target ratio - Android Camera

Android examples for Camera:Camera Preview

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Description

get Optimal Preview Size with target ratio

Demo Code

/*/*  w  w w.j  a va2 s  .c o m*/
Copyright (C) 2016, Silent Circle, LLC.  All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
    * Any redistribution, use, or modification is done solely for personal
      benefit and not for any commercial purpose or for monetary gain
    * Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in the
      documentation and/or other materials provided with the distribution.
    * Neither the name Silent Circle nor the
      names of its contributors may be used to endorse or promote products
      derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL SILENT CIRCLE, LLC BE LIABLE FOR ANY
DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
//package com.java2s;
import android.app.Activity;
import android.graphics.Point;
import android.hardware.Camera;

import android.view.Display;

import java.util.List;

public class Main {
    public static Camera.Size getOptimalPreviewSize(
            Activity currentActivity, List<Camera.Size> sizes,
            double targetRatio) {
        // Use a very small tolerance because we want an exact match.
        final double ASPECT_TOLERANCE = 0.001;
        if (sizes == null)
            return null;

        Camera.Size optimalSize = null;
        double minDiff = Double.MAX_VALUE;

        // Because of bugs of overlay and layout, we sometimes will try to
        // layout the viewfinder in the portrait orientation and thus get the
        // wrong size of preview surface. When we change the preview size, the
        // new overlay will be created before the old one closed, which causes
        // an exception. For now, just get the screen size.
        Point point = getDefaultDisplaySize(currentActivity, new Point());
        int targetHeight = Math.min(point.x, point.y);
        // Try to find an size match aspect ratio and size
        for (Camera.Size size : sizes) {
            double ratio = (double) size.width / size.height;
            if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE)
                continue;
            if (Math.abs(size.height - targetHeight) < minDiff) {
                optimalSize = size;
                minDiff = Math.abs(size.height - targetHeight);
            }
        }
        // Cannot find the one match the aspect ratio. This should not happen.
        // Ignore the requirement.
        if (optimalSize == null) {
            minDiff = Double.MAX_VALUE;
            for (Camera.Size size : sizes) {
                if (Math.abs(size.height - targetHeight) < minDiff) {
                    optimalSize = size;
                    minDiff = Math.abs(size.height - targetHeight);
                }
            }
        }
        return optimalSize;
    }

    private static Point getDefaultDisplaySize(Activity activity, Point size) {
        Display d = activity.getWindowManager().getDefaultDisplay();
        d.getSize(size);

        return size;
    }
}

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