Mega Code Archive
Increase Contrast, Reduce Brightness
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package app.test;
import java.io.FileNotFoundException;
import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.ColorMatrix;
import android.graphics.ColorMatrixColorFilter;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.net.Uri;
import android.os.Bundle;
import android.util.Log;
import android.view.Display;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
public class Test extends Activity implements OnClickListener {
ImageView chosenImageView;
Button choosePicture;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
chosenImageView = (ImageView) this.findViewById(R.id.ChosenImageView);
choosePicture = (Button) this.findViewById(R.id.ChoosePictureButton);
choosePicture.setOnClickListener(this);
}
public void onClick(View v) {
Intent choosePictureIntent = new Intent(Intent.ACTION_PICK,
android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(choosePictureIntent, 0);
}
protected void onActivityResult(int requestCode, int resultCode,
Intent intent) {
super.onActivityResult(requestCode, resultCode, intent);
if (resultCode == RESULT_OK) {
Uri imageFileUri = intent.getData();
Display currentDisplay = getWindowManager().getDefaultDisplay();
int dw = currentDisplay.getWidth();
int dh = currentDisplay.getHeight() / 2 - 100;
try {
BitmapFactory.Options bmpFactoryOptions = new BitmapFactory.Options();
bmpFactoryOptions.inJustDecodeBounds = true;
Bitmap bmp = BitmapFactory
.decodeStream(getContentResolver().openInputStream(
imageFileUri), null, bmpFactoryOptions);
int heightRatio = (int) Math.ceil(bmpFactoryOptions.outHeight
/ (float) dh);
int widthRatio = (int) Math.ceil(bmpFactoryOptions.outWidth
/ (float) dw);
if (heightRatio > 1 && widthRatio > 1) {
if (heightRatio > widthRatio) {
bmpFactoryOptions.inSampleSize = heightRatio;
} else {
bmpFactoryOptions.inSampleSize = widthRatio;
}
}
bmpFactoryOptions.inJustDecodeBounds = false;
bmp = BitmapFactory.decodeStream(getContentResolver().openInputStream(imageFileUri), null, bmpFactoryOptions);
Bitmap alteredBitmap = Bitmap.createBitmap(bmp.getWidth(), bmp
.getHeight(), bmp.getConfig());
Canvas canvas = new Canvas(alteredBitmap);
Paint paint = new Paint();
ColorMatrix cm = new ColorMatrix();
// Increase Contrast, Slightly Reduce Brightness
float contrast = 3;
float brightness = -5;
cm.set(new float[] { contrast, 0, 0, 0, brightness, 0,
contrast, 0, 0, brightness, 0, 0, contrast, 0,
brightness, 0, 0, 0, 1, 0 });
paint.setColorFilter(new ColorMatrixColorFilter(cm));
Matrix matrix = new Matrix();
canvas.drawBitmap(bmp, matrix, paint);
ImageView alteredImageView = (ImageView) this
.findViewById(R.id.AlteredImageView);
alteredImageView.setImageBitmap(alteredBitmap);
chosenImageView.setImageBitmap(bmp);
} catch (Exception e) {
Log.v("ERROR", e.toString());
}
}
}
}
//main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<Button
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Choose Picture" android:id="@+id/ChoosePictureButton"/>
<ImageView android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/ChosenImageView"></ImageView>
<ImageView android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/AlteredImageView"></ImageView>
</LinearLayout>
]]>