Using the camera object you can override a function setPreviewCallback
. from that function you would get an array of byte data. Which you can convert to bitmap or you can save them in an array of array.
Assuming that you were extends SurfaceView
and Implements SurfaceHolder.Callback
Code looks like,
mCamera.setPreviewCallback(new PreviewCallback() {
public void onPreviewFrame(byte[] data, Camera camera) {
//do some operations using data
}
});
If you want to get the RGB value you can use this function,
static public void decodeYUV420SP(int[] rgb, byte[] yuv420sp, int width,
int height) {
final int frameSize = width * height;
for (int j = 0, yp = 0; j < height; j++) {
int uvp = frameSize + (j >> 1) * width, u = 0, v = 0;
for (int i = 0; i < width; i++, yp++) {
int y = (0xff & ((int) yuv420sp[yp])) - 16;
if (y < 0)
y = 0;
if ((i & 1) == 0) {
v = (0xff & yuv420sp[uvp++]) - 128;
u = (0xff & yuv420sp[uvp++]) - 128;
}
int y1192 = 1192 * y;
int r = (y1192 + 1634 * v);
int g = (y1192 - 833 * v - 400 * u);
int b = (y1192 + 2066 * u);
if (r < 0)
r = 0;
else if (r > 262143)
r = 262143;
if (g < 0)
g = 0;
else if (g > 262143)
g = 262143;
if (b < 0)
b = 0;
else if (b > 262143)
b = 262143;
rgb[yp] = 0xff000000 | ((r << 6) & 0xff0000)
| ((g >> 2) & 0xff00) | ((b >> 10) & 0xff);
}
}
}
I think this is what you want as an answer. If i am wrong, please let me know whats is your actual requirement
For getting the green value, you can use the below code,
static public void calculateColor(int[] rgb, int[] color,
int width, int height, int component) {
for (int bin = 0; bin < 256; bin++) {
color[bin] = 0;
} // bin
int start = 0;
int end = width * height;
if (component == 0) // red
{
for (int pix = start; pix < end; pix += 3) {
int pixVal = (rgb[pix] >> 16) & 0xff;
color[pixVal]++;
} // pix
} else if (component == 1) // green
{
for (int pix = start; pix < end; pix += 3) {
int pixVal = (rgb[pix] >> 8) & 0xff;
color[pixVal]++;
} // pix
} else // blue
{
for (int pix = start; pix < end; pix += 3) {
int pixVal = rgb[pix] & 0xff;
color[pixVal]++;
} // pix
}
}
Calling this function would return the value of green for every pixel. If you wants the green value for a particular pixel, you have to modify this code.