Android, Image compression App

i have to create and submit an image compression app as a project, Just like they have in watsapp, so i searched a little and found out the code but when i use that in Android studio then lots of terms like "Bitmap" are shown to be not recognized. Can anyone tell how to paste the code and connect or relate that to my blank file in order to make that run, Here's the code,

public String compressImage(String imageUri) {

String filePath = getRealPathFromURI(imageUri);
Bitmap scaledBitmap = null;

BitmapFactory.Options options = new BitmapFactory.Options();

//      by setting this field as true, the actual bitmap pixels are not loaded in the memory. Just the bounds are loaded. If
//      you try the use the bitmap here, you will get null.
options.inJustDecodeBounds = true;
Bitmap bmp = BitmapFactory.decodeFile(filePath, options);

int actualHeight = options.outHeight;
int actualWidth = options.outWidth;

//      max Height and width values of the compressed image is taken as 816x612

float maxHeight = 816.0f;
float maxWidth = 612.0f;
float imgRatio = actualWidth / actualHeight;
float maxRatio = maxWidth / maxHeight;

//      width and height values are set maintaining the aspect ratio of the image

if (actualHeight > maxHeight || actualWidth > maxWidth) {
if (imgRatio < maxRatio) {               imgRatio = maxHeight / actualHeight;                actualWidth = (int) (imgRatio * actualWidth);               actualHeight = (int) maxHeight;             } else if (imgRatio > maxRatio) {
imgRatio = maxWidth / actualWidth;
actualHeight = (int) (imgRatio * actualHeight);
actualWidth = (int) maxWidth;
} else {
actualHeight = (int) maxHeight;
actualWidth = (int) maxWidth;

}
}

//      setting inSampleSize value allows to load a scaled down version of the original image

options.inSampleSize = calculateInSampleSize(options, actualWidth, actualHeight);

//      inJustDecodeBounds set to false to load the actual bitmap
options.inJustDecodeBounds = false;

//      this options allow android to claim the bitmap memory if it runs low on memory
options.inPurgeable = true;
options.inInputShareable = true;
options.inTempStorage = new byte[16 * 1024];

try {
//          load the bitmap from its path
bmp = BitmapFactory.decodeFile(filePath, options);
} catch (OutOfMemoryError exception) {
exception.printStackTrace();

}
try {
scaledBitmap = Bitmap.createBitmap(actualWidth, actualHeight,Bitmap.Config.ARGB_8888);
} catch (OutOfMemoryError exception) {
exception.printStackTrace();
}

float ratioX = actualWidth / (float) options.outWidth;
float ratioY = actualHeight / (float) options.outHeight;
float middleX = actualWidth / 2.0f;
float middleY = actualHeight / 2.0f;

Matrix scaleMatrix = new Matrix();
scaleMatrix.setScale(ratioX, ratioY, middleX, middleY);

Canvas canvas = new Canvas(scaledBitmap);
canvas.setMatrix(scaleMatrix);
canvas.drawBitmap(bmp, middleX - bmp.getWidth() / 2, middleY - bmp.getHeight() / 2, new Paint(Paint.FILTER_BITMAP_FLAG));

//      check the rotation of the image and display it properly
ExifInterface exif;
try {
exif = new ExifInterface(filePath);

int orientation = exif.getAttributeInt(
ExifInterface.TAG_ORIENTATION, 0);
Log.d("EXIF", "Exif: " + orientation);
Matrix matrix = new Matrix();
if (orientation == 6) {
matrix.postRotate(90);
Log.d("EXIF", "Exif: " + orientation);
} else if (orientation == 3) {
matrix.postRotate(180);
Log.d("EXIF", "Exif: " + orientation);
} else if (orientation == 8) {
matrix.postRotate(270);
Log.d("EXIF", "Exif: " + orientation);
}
scaledBitmap = Bitmap.createBitmap(scaledBitmap, 0, 0,
scaledBitmap.getWidth(), scaledBitmap.getHeight(), matrix,
true);
} catch (IOException e) {
e.printStackTrace();
}

FileOutputStream out = null;
String filename = getFilename();
try {
out = new FileOutputStream(filename);

//  write the compressed bitmap at the destination specified by filename.
scaledBitmap.compress(Bitmap.CompressFormat.JPEG, 80, out);

} catch (FileNotFoundException e) {
e.printStackTrace();
}

return filename;

}

And what i see in my blank file is,

package com.example.codyrichards.app_1;

import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;


public class activity_1 extends ActionBarActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_activity_1);
}
private static Bitmap codec(Bitmap src, Bitmap.CompressFormat format,
int quality) {
ByteArrayOutputStream os = new ByteArrayOutputStream();
src.compress(format, quality, os);

byte[] array = os.toByteArray();
return BitmapFactory.decodeByteArray(array, 0, array.length);
}

private static class SampleView extends View {

// CONSTRUCTOR
public SampleView(Context context) {
super(context);
setFocusable(true);

}
@Override
protected void onDraw(Canvas canvas) {
Paint paint = new Paint();

canvas.drawColor(Color.GRAY);

//  you need to insert some image flower_blue into res/drawable folder
Bitmap b = BitmapFactory.decodeResource(getResources(), R.drawable.flower_blue);
// Best of quality is 80 and more, 3 is very low quality of image
Bitmap bJPGcompress = codec(b, Bitmap.CompressFormat.JPEG, 3);
// get dimension of bitmap getHeight()  getWidth()
int h = b.getHeight();

canvas.drawBitmap(b, 10,10, paint);
canvas.drawBitmap(bJPGcompress, 10,10 + h + 10, paint);

}
}
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_activity_1, menu);
return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();

//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}

return super.onOptionsItemSelected(item);
}
}