get Optimal Preview Size by width and height - Android Camera

Android examples for Camera:Camera Preview

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Description

get Optimal Preview Size by width and height

Demo Code


//package com.java2s;

import java.util.List;

import android.hardware.Camera;

public class Main {
    public static Camera.Size getOptimalPreviewSize(
            List<Camera.Size> sizes, int w, int h) {
        // Use a very small tolerance because we want an exact match.
        final double ASPECT_TOLERANCE = 0.1;
        double targetRatio = (double) w / h;
        if (sizes == null)
            return null;

        Camera.Size optimalSize = null;/*  w  w  w  .ja va  2 s .c  om*/

        // Start with max value and refine as we iterate over available preview sizes. This is the
        // minimum difference between view and camera height.
        double minDiff = Double.MAX_VALUE;

        // Target view height
        int targetHeight = h;

        // Try to find a preview size that matches aspect ratio and the target view size.
        // Iterate over all available sizes and pick the largest size that can fit in the view and
        // still maintain the aspect ratio.
        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 preview size that matches the aspect ratio, 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;
    }
}

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