Image Convert PNG to BMP format.

In this tutorial explain how to convert  .png image to .bmp format.

Example:

import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.ByteBuffer;

import android.graphics.Bitmap;

public class AndroidBmpUtil {
    private static  final int BMP_WIDTH_OF_TIMES = 4;
    private  static final int BYTE_PER_PIXEL = 3;

    public static boolean save(Bitmap orgBitmap, String filePath){

        if(orgBitmap == null){
            return false;
        }

        if(filePath == null){
            return false;
        }

        boolean isSaveSuccess = true;


        int width = orgBitmap.getWidth();
        int height = orgBitmap.getHeight();


        int dummySize = 0;
        byte[] dummyBytesPerRow = null;
        boolean hasDummy = false;
        if(isBmpWidth4Times(width)){
            hasDummy = true;
            dummySize = BMP_WIDTH_OF_TIMES - (width % BMP_WIDTH_OF_TIMES);
            dummyBytesPerRow = new byte[dummySize * BYTE_PER_PIXEL];
            for(int i = 0; i < dummyBytesPerRow.length; i++){
                dummyBytesPerRow[i] = (byte)0xFF;
            }
        }

        int[] pixels = new int[width * height];
        int imageSize = pixels.length * BYTE_PER_PIXEL + (height * dummySize * BYTE_PER_PIXEL);
        int imageDataOffset = 0x36;
        int fileSize = imageSize + imageDataOffset;


        orgBitmap.getPixels(pixels, 0, width, 0, 0, width, height);


        ByteBuffer buffer = ByteBuffer.allocate(fileSize);

        try {

            buffer.put((byte)0x42);
            buffer.put((byte)0x4D);

            //size            buffer.put(writeInt(fileSize));

            //reserved            buffer.put(writeShort((short)0));
            buffer.put(writeShort((short)0));

            //image data start offset            buffer.put(writeInt(imageDataOffset));

            //size            buffer.put(writeInt(0x28));

            //width, height            buffer.put(writeInt(width));
            buffer.put(writeInt(height));

            //planes            buffer.put(writeShort((short)1));

            //bit count            buffer.put(writeShort((short)24));

            //bit compression            buffer.put(writeInt(0));

            //image data size            buffer.put(writeInt(imageSize));

            //horizontal resolution in pixels per meter            buffer.put(writeInt(0));

            //vertical resolution in pixels per meter (unreliable)            buffer.put(writeInt(0));


            buffer.put(writeInt(0));


            buffer.put(writeInt(0));


            int row = height;
            int col = width;
            int startPosition = 0;
            int endPosition = 0;

            while( row > 0 ){

                startPosition = (row - 1) * col;
                endPosition = row * col;

                for(int i = startPosition; i < endPosition; i++ ){
                    buffer.put(write24BitForPixcel(pixels[i]));

                    if(hasDummy){
                        if(isBitmapWidthLastPixcel(width, i)){
                            buffer.put(dummyBytesPerRow);
                        }
                    }
                }
                row--;
            }

            FileOutputStream fos = new FileOutputStream(filePath);
            fos.write(buffer.array());
            fos.close();
        } catch (IOException e1) {
            e1.printStackTrace();
            isSaveSuccess = false;
        }
        finally{

        }

        return isSaveSuccess;
    }


    private static  boolean isBitmapWidthLastPixcel(int width, int i) {
        return i > 0 && (i % (width - 1)) == 0;
    }


    private static  boolean isBmpWidth4Times(int width) {
        return width % BMP_WIDTH_OF_TIMES > 0;
    }


    private static  byte[] writeInt(int value) throws IOException {
        byte[] b = new byte[4];

        b[0] = (byte)(value & 0x000000FF);
        b[1] = (byte)((value & 0x0000FF00) >> 8);
        b[2] = (byte)((value & 0x00FF0000) >> 16);
        b[3] = (byte)((value & 0xFF000000) >> 24);

        return b;
    }


    private static  byte[] write24BitForPixcel(int value) throws IOException {
        byte[] b = new byte[3];

        b[0] = (byte)(value & 0x000000FF);
        b[1] = (byte)((value & 0x0000FF00) >> 8);
        b[2] = (byte)((value & 0x00FF0000) >> 16);

        return b;
    }


    private static  byte[] writeShort(short value) throws IOException {
        byte[] b = new byte[2];

        b[0] = (byte)(value & 0x00FF);
        b[1] = (byte)((value & 0xFF00) >> 8);

        return b;
    }

}

Create Main Class

GestureOverlayView mSignature;

mSignature=  (GestureOverlayView) findViewById(R.id.shape_1_1);
WitnessSignature.setDrawingCacheEnabled(true);

Bitmap bitmap= Bitmap.createBitmap(mSignature.getDrawingCache());

AndroidBmpUtil.save(getResized(offenderBitmap, 384), 

Environment.getExternalStoragePublicDirectory(
        Environment.DIRECTORY_PICTURES).getAbsolutePath() + "/offender.bmp");

File fil = new File(Environment.getExternalStoragePublicDirectory(
        Environment.DIRECTORY_PICTURES).getAbsolutePath(), "offender.bmp");