Android Camera Set setBestExposure(Camera.Parameters parameters, boolean lightOn)

Description

set Best Exposure

License

Apache License

Declaration

public static void setBestExposure(Camera.Parameters parameters,
            boolean lightOn) 

Method Source Code

//package com.java2s;
/*/* w  w w  . java2s .  c o m*/
 * Copyright (C) 2014 ZXing authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import android.hardware.Camera;

import android.util.Log;

public class Main {
    private static final String TAG = "CameraConfiguration";
    private static final float MAX_EXPOSURE_COMPENSATION = 1.5f;
    private static final float MIN_EXPOSURE_COMPENSATION = 0.0f;

    public static void setBestExposure(Camera.Parameters parameters,
            boolean lightOn) {
        int minExposure = parameters.getMinExposureCompensation();
        int maxExposure = parameters.getMaxExposureCompensation();
        float step = parameters.getExposureCompensationStep();
        if ((minExposure != 0 || maxExposure != 0) && step > 0.0f) {
            // Set low when light is on
            float targetCompensation = lightOn ? MIN_EXPOSURE_COMPENSATION
                    : MAX_EXPOSURE_COMPENSATION;
            int compensationSteps = Math.round(targetCompensation / step);
            float actualCompensation = step * compensationSteps;
            // Clamp value:
            compensationSteps = Math.max(
                    Math.min(compensationSteps, maxExposure), minExposure);
            if (parameters.getExposureCompensation() == compensationSteps) {
                Log.i(TAG, "Exposure compensation already set to "
                        + compensationSteps + " / " + actualCompensation);
            } else {
                Log.i(TAG, "Setting exposure compensation to "
                        + compensationSteps + " / " + actualCompensation);
                parameters.setExposureCompensation(compensationSteps);
            }
        } else {
            Log.i(TAG, "Camera does not support exposure compensation");
        }
    }
}

Related

1. setBarcodeSceneMode(Camera.Parameters parameters)
2. setBestPreviewFPS(Camera.Parameters parameters)
3. setBestPreviewFPS(Camera.Parameters parameters, int minFPS, int maxFPS)
4. setCameraDisplayOrientation(Context mContext, int cameraId, Camera camera)
5. setFocus(Camera.Parameters parameters, boolean autoFocus, boolean disableContinuous, boolean safeMode)