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Add camera focus distances API.

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Applications can use this API to estimate the distance
between the subject and the camera.

bug:1955650
Change-Id: Ie6c8ea4971759cab6c9bcdda2c5ceb5925791c27
This commit is contained in:
Wu-cheng Li
2010-05-13 19:31:02 +08:00
parent aef87aa90c
commit e339c5edbe
4 changed files with 142 additions and 0 deletions
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46
api/current.xml
View File

@ -75570,6 +75570,19 @@
visibility="public"
>
</method>
<method name="getFocusDistances"
return="void"
abstract="false"
native="false"
synchronized="false"
static="false"
final="false"
deprecated="not deprecated"
visibility="public"
>
<parameter name="output" type="float[]">
</parameter>
</method>
<method name="getFocusMode"
return="java.lang.String"
abstract="false"
@ -76492,6 +76505,39 @@
visibility="public"
>
</field>
<field name="FOCUS_DISTANCE_FAR_INDEX"
type="int"
transient="false"
volatile="false"
value="2"
static="true"
final="true"
deprecated="not deprecated"
visibility="public"
>
</field>
<field name="FOCUS_DISTANCE_NEAR_INDEX"
type="int"
transient="false"
volatile="false"
value="0"
static="true"
final="true"
deprecated="not deprecated"
visibility="public"
>
</field>
<field name="FOCUS_DISTANCE_OPTIMAL_INDEX"
type="int"
transient="false"
volatile="false"
value="1"
static="true"
final="true"
deprecated="not deprecated"
visibility="public"
>
</field>
<field name="FOCUS_MODE_AUTO"
type="java.lang.String"
transient="false"

73
core/java/android/hardware/Camera.java
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@ -762,6 +762,8 @@ public class Camera {
private static final String KEY_ZOOM_RATIOS = "zoom-ratios";
private static final String KEY_ZOOM_SUPPORTED = "zoom-supported";
private static final String KEY_SMOOTH_ZOOM_SUPPORTED = "smooth-zoom-supported";
private static final String KEY_FOCUS_DISTANCES = "focus-distances";
// Parameter key suffix for supported values.
private static final String SUPPORTED_VALUES_SUFFIX = "-values";
@ -874,10 +876,30 @@ public class Camera {
*/
public static final String FOCUS_MODE_EDOF = "edof";
// Indices for focus distance array.
/**
* The array index of near focus distance for use with
* {@link #getFocusDistances(float[])}.
*/
public static final int FOCUS_DISTANCE_NEAR_INDEX = 0;
/**
* The array index of optimal focus distance for use with
* {@link #getFocusDistances(float[])}.
*/
public static final int FOCUS_DISTANCE_OPTIMAL_INDEX = 1;
/**
* The array index of far focus distance for use with
* {@link #getFocusDistances(float[])}.
*/
public static final int FOCUS_DISTANCE_FAR_INDEX = 2;
/**
* Continuous focus mode. The camera continuously tries to focus. This
* is ideal for shooting video or shooting photo of moving object.
* Continuous focus starts when {@link #autoFocus(AutoFocusCallback)} is
* called. Continuous focus stops when {@link #cancelAutoFocus()} is
* called. AutoFocusCallback will be only called once as soon as the
* picture is in focus.
*/
@ -1814,6 +1836,42 @@ public class Camera {
return TRUE.equals(str);
}
/**
* Gets the distances from the camera to where an object appears to be
* in focus. The object is sharpest at the optimal focus distance. The
* depth of field is the far focus distance minus near focus distance.
*
* Focus distances may change after calling {@link
* #autoFocus(AutoFocusCallback)}, {@link #cancelAutoFocus}, or {@link
* #startPreview()}. Applications can call {@link #getParameters()}
* and this method anytime to get the latest focus distances. If the
* focus mode is FOCUS_MODE_EDOF, the values may be all 0, which means
* focus distance is not applicable. If the focus mode is
* FOCUS_MODE_CONTINUOUS and autofocus has started, focus distances may
* change from time to time.
*
* Far focus distance > optimal focus distance > near focus distance. If
* the far focus distance is infinity, the value will be
* Float.POSITIVE_INFINITY.
*
* @param output focus distances in meters. output must be a float
* array with three elements. Near focus distance, optimal focus
* distance, and far focus distance will be filled in the array.
* @see #NEAR_FOCUS_DISTANCE_INDEX
* @see #OPTIMAL_FOCUS_DISTANCE_INDEX
* @see #FAR_FOCUS_DISTANCE_INDEX
*/
public void getFocusDistances(float[] output) {
if (output == null || output.length != 3) {
throw new IllegalArgumentException(
"output must be an float array with three elements.");
}
List<Float> distances = splitFloat(get(KEY_FOCUS_DISTANCES));
output[0] = distances.get(0);
output[1] = distances.get(1);
output[2] = distances.get(2);
}
// Splits a comma delimited string to an ArrayList of String.
// Return null if the passing string is null or the size is 0.
private ArrayList<String> split(String str) {
@ -1843,6 +1901,21 @@ public class Camera {
return substrings;
}
// Splits a comma delimited string to an ArrayList of Float.
// Return null if the passing string is null or the size is 0.
private ArrayList<Float> splitFloat(String str) {
if (str == null) return null;
StringTokenizer tokenizer = new StringTokenizer(str, ",");
ArrayList<Float> substrings = new ArrayList<Float>();
while (tokenizer.hasMoreElements()) {
String token = tokenizer.nextToken();
substrings.add(Float.parseFloat(token));
}
if (substrings.size() == 0) return null;
return substrings;
}
// Returns the value of a float parameter.
private float getFloat(String key, float defaultValue) {
try {

21
include/camera/CameraParameters.h
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@ -221,9 +221,30 @@ public:
// Example value: "true". Read only.
static const char KEY_SMOOTH_ZOOM_SUPPORTED[];
// The distances (in meters) from the camera to where an object appears to
// be in focus. The object is sharpest at the optimal focus distance. The
// depth of field is the far focus distance minus near focus distance.
//
// Applications can read this parameter anytime to get the latest focus
// distances. If the focus mode is FOCUS_MODE_EDOF, the values may be all
// 0, which means focus distance is not applicable. If the focus mode is
// FOCUS_MODE_CONTINUOUS and autofocus has started, focus distances may
// change from time to time.
//
// Far focus distance > optimal focus distance > near focus distance. If
// the far focus distance is infinity, the value should be "Infinity" (case
// sensitive). The format is three float values separated by commas. The
// first is near focus distance. The second is optimal focus distance. The
// third is far focus distance.
// Example value: "0.95,1.9,Infinity" or "0.049,0.05,0.051". Read only.
static const char KEY_FOCUS_DISTANCES[];
// Value for KEY_ZOOM_SUPPORTED or KEY_SMOOTH_ZOOM_SUPPORTED.
static const char TRUE[];
// Value for KEY_FOCUS_DISTANCES.
static const char INFINITY[];
// Values for white balance settings.
static const char WHITE_BALANCE_AUTO[];
static const char WHITE_BALANCE_INCANDESCENT[];

2
libs/camera/CameraParameters.cpp
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@ -69,8 +69,10 @@ const char CameraParameters::KEY_MAX_ZOOM[] = "max-zoom";
const char CameraParameters::KEY_ZOOM_RATIOS[] = "zoom-ratios";
const char CameraParameters::KEY_ZOOM_SUPPORTED[] = "zoom-supported";
const char CameraParameters::KEY_SMOOTH_ZOOM_SUPPORTED[] = "smooth-zoom-supported";
const char CameraParameters::KEY_FOCUS_DISTANCES[] = "focus-distances";
const char CameraParameters::TRUE[] = "true";
const char CameraParameters::INFINITY[] = "Infinity";
// Values for white balance settings.
const char CameraParameters::WHITE_BALANCE_AUTO[] = "auto";