Android Camera API ISO Setting?

Question

Would anyone know where to control the ISO setting for the camera from in the Android SDK ? It should be possible as the native camera application on the HTC Desire has ISO

Answer 1

since I had the same problem of finding if the device has an ISO parameter I looked at this answer https://stackoverflow.com/a/23567103/3976589 and saw that @j.c had solved the problem for 8/18 devices by listing some parameters that he had found on different devices. Based on that listing I found that each paramter contains the words iso and values (sometimes only those words, sometimes something additional).

So if I list all of the camera parameters and search for a strings that contain both words I will know what is the name of the ISO parameter, if it exists. Furthermore if the parameter exists I can take the supported ISO values and if I want to set one of those values i.e. change the camera parameter, I can just remove the -values at the end of the iso-values parameter and then I can change the ISO value successfully.

I will now share my code for this task. First a snippet that retrieves a list with supported ISO values.

    private String ISOValuesParameter = null;
    private String ISOParameter = null;
    private String ISOValues = null;


    private void initCamera() {
        Camera mCamera = Camera.open();

        // this will list supported values
        String ISOvalues = getISOValues(); 
        textViewISO = (TextView) findViewById(R.id.viewISO);
        textViewISO.setText(ISOvalues);

    // setting Minimum ISO value
    if(ISOValuesParameter != null) {
        Camera.Parameters params = mCamera.getParameters();

        ISOParameter = ISOValuesParameter.replace("-values", "");
        params.set(ISOParameter, getMinISO());

        mCamera.setParameters(params);

        // get the updated ISO value
        params = mCamera.getParameters();

        String ISO = params.get(ISOParameter);

        Toast.makeText(this,"ISO set to: " + ISO, Toast.LENGTH_SHORT).show();
    }

    }

    // returns a list with supported ISO values
    private String getISOValues() {
            ISOValuesParamter = getISOValuesParameter();
            Camera.Parameters params = mCamera.getParameters();
            ISOValues = params.get(ISOValuesParamter);

            return ISOValues!=null ? ISOValues : "ISO not supported";
    }

    // this will return the name of the ISO parameter containing supported ISO values
    private String getISOValuesParameter() {
            Camera.Parameters params = mCamera.getParameters();

            String flatten = params.flatten();
            String[] paramsSeparated = flatten.split(";");
            for(String cur : paramsSeparated) {
                if(cur.contains("iso") && cur.contains("values")) {
                    return cur.substring(0,cur.indexOf('='));
                }
            }

            return null;
    }

This snippet only lists the supported ISO values. In my application I needed to pick the lowest ISO. Here is my solution:

private String getMinISO() {
    if(ISOValues == null) {
        return null;
    }

    String[] ISOarray = ISOValues.split(",");
    Arrays.sort(ISOarray, myComparator);

    String minISO = ISOarray[ISOarray.length-1];

    return minISO;
}

Here myComparator is a class that compares two strings and sorts the array in descending order. All alphabet words are at the beginning and all numbers are at the end. Here is my implementation:

// Singelton class
public class MyComparator implements  Comparator {

private static MyComparator myComparator = null;

private MyComparator() {}

@Override
public int compare(String a, String b) {
    return compareString(a,b);
}

public static int compareString(String a, String b) {
    if (a.length() > b.length())
        return -1;
    if (a.length() == b.length()) {
        if (a.compareTo(b) > 0)
            return -1;
        else if (a.compareTo(b) == 0)
            return 0;
    }

    return 1;
}

public static synchronized MyComparator getInstance() {
    if(myComparator==null) {
        myComparator = new MyComparator();
    }

    return myComparator;
}

}

I hope my answer helps other people. :)

Cheers! @ee3509