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 settings.

Answer 1

you should take a look at the methods flatten(), unflatten(), get(String key), set(String key, String value) in android.hardware.Camera.Parameters. Also consider the source code of that class. It might make things clearer.

First you need to obtain the Camera.Parameters. Unflatten it to a String and investigate it. I am developing on a HTC Desire as well an get the following String:

sharpness-max=30;zoom=0;taking-picture-zoom=0;zoom-supported=true;sharpness-min=0;sharpness=10;contrast=5;whitebalance=auto;jpeg-quality=100;preview-format-values=yuv420sp;jpeg-thumbnail-quality=75;preview-format=yuv420sp;preview-size=640x480;focal-length=3.53;iso=auto;meter-mode=meter-center;front-camera-mode=mirror;flash-mode-values=off,auto,on,torch;preview-frame-rate-values=15;preview-frame-rate=15;focus-mode-values=auto,infinity;jpeg-thumbnail-width=640;jpeg-thumbnail-size-values=640x480,512x384,384x288,0x0;zoom-ratios=100,114,131,151,174,200;saturation-def=5;preview-size-values=1280x720,800x480,768x432,720x480,640x480,576x432,480x320,400x240,384x288,352x288,320x240,272x272,240x240,240x160,176x144,160x120;smart-contrast=off;picture-size-values=2592x1952,2592x1456,2592x1936,2592x1728,2592x1552,2048x1536,2048x1360,2048x1216,2048x1152,1600x1200,1584x1056,1280x960,1280x848,1280x768,1280x720,1024x768,640x480,640x416,640x384,640x368,512x384,400x400,272x272;contrast-min=0;min-exposure-compensation=-4;brightness-min=0;antibanding=auto;taking-picture-zoom-min=0;saturation-min=1;contrast-max=10;vertical-view-angle=42.5;taking-picture-zoom-max=21;contrast-def=5;brightness-max=6;horizontal-view-angle=54.8;brightness=3;jpeg-thumbnail-height=480;cam-mode=0;focus-mode=auto;sharpness-def=10;front-camera-mode-values=mirror,reverse;picture-format-values=jpeg;saturation-max=10;max-exposure-compensation=4;exposure-compensation=0;exposure-compensation-step=0.5;flash-mode=off;effect-values=none,mono,negative,solarize,sepia,posterize,aqua;meter-mode-values=meter-average,meter-center,meter-spot;picture-size=2592x1952;max-zoom=5;effect=none;saturation=5;whitebalance-values=auto,incandescent,fluorescent,daylight,cloudy-daylight;picture-format=jpeg;brightness-def=3;iso-values=auto,deblur,100,200,400,800,1250;enable-caf=off;antibanding-values=off,50hz,60hz,auto

So basically there is a key called iso-values to retrieve the supported values and a key iso which holds the current value.

You can do the following:

Camera cam = Camera.open();
Camera.Parameters camParams = cam.getParameters();
String supportedIsoValues = camParams.get("iso-values"); //supported values, comma separated String
camParams.set("iso", (String)newValue);
cam.setParameters(camParams);

And with reference to the unflattened parameters I would assume that there is a difference between the iso and exposure compensation settings.