Extension ColorFilter image. Complementary color. Grayscale. Source code. Transparent color. FloodFill

Juan_Antonio · March 22, 2023, 4:42pm

I've been making an extension to convert one image to another with its complementary colors.

When I finished it I realized that @Gordon_Lu had already done a great and complete extension on the subject.

Anyway, I'm sharing here my extension and its source code in case anyone might be interested.

Source code

Source code: KIO4_ColorFilter.java

package com.KIO4_ColorFilter;

import com.google.appinventor.components.annotations.DesignerComponent;
import com.google.appinventor.components.annotations.SimpleFunction;
import com.google.appinventor.components.annotations.SimpleObject;
import com.google.appinventor.components.common.ComponentCategory;
import com.google.appinventor.components.runtime.*;
import android.content.Context;

import android.graphics.Bitmap;
import android.net.Uri;
import android.graphics.Matrix;
import android.graphics.ColorMatrix;
import android.graphics.ColorMatrixColorFilter;
import android.graphics.Paint;
import android.graphics.BitmapFactory;
import android.widget.ImageView;
import android.view.View;
import android.graphics.Canvas;

import java.io.IOException;
import android.os.Environment;

import java.io.File;
import java.io.FileOutputStream;

@DesignerComponent(version = 1,
    description = "Color filter. Change the color of an image.",
    category = ComponentCategory.EXTENSION,
    nonVisible = true,
	helpUrl  = "https://developer.android.com/reference/android/graphics/ColorMatrix",
    iconName ="") 
@SimpleObject(external = true)

public class KIO4_ColorFilter extends AndroidNonvisibleComponent implements Component {
    public static final int VERSION = 1;
    private ComponentContainer container;
	private Context context;
	private ImageView mi_imagen = null;
	private String colores ="";

    public KIO4_ColorFilter(ComponentContainer container) {
        super(container.$form());
        this.container = container;
		context = (Context) container.$context();
    }
	
////////////////////// FUNCIONES ////////////////////////////////////////////////////////////////////// //.
@SimpleFunction(description = "Get outFile in ASD. colorMatrix is a string, example: -1,0,0,0,255,0,-1,0,0,255,0,0,-1,0,255,0,0,0,1,0")
   public void ChangeColorMatrix(String pathImage,  String outFile, int density, String colorsMatrix) {
    // mi_imagen =  (ImageView) imagen.getView();
	pathImage = pathImage.replace("file://", "");
	Uri imgUri = Uri.parse(pathImage);
	colores = colorsMatrix;

    try {
        BitmapFactory.Options options = new BitmapFactory.Options();
        options.inSampleSize = 1; // 1 - means max size. 4 - means maxsize/4 size.
        options.inTargetDensity = density; // 100
        Bitmap bitmap = BitmapFactory.decodeFile(imgUri.getPath(), options);
		
		String asd = context.getExternalFilesDir(null).toString();
		File myDir = new File(asd);
		File file = new File(myDir, outFile);
		FileOutputStream out = new FileOutputStream(file);
		
        bitmap = FilterColor(bitmap);
		bitmap.compress(Bitmap.CompressFormat.PNG, 100, out);
		out.flush();
		out.close();
       
    } catch (Exception e) {
    //    Log.e(TAG, e.getMessage());
    }
}

public Bitmap FilterColor(Bitmap bmpOriginal){        
    int height = bmpOriginal.getHeight();
    int width = bmpOriginal.getWidth();    

    Bitmap bmpFilter = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
    Canvas c = new Canvas(bmpFilter);
	
    String[] parts = colores.split(",");
    float[] matrix = new float[parts.length];
    for (int i = 0; i < parts.length; ++i) {
        float number = Float.parseFloat(parts[i]);
        matrix[i] = number;
    };

    Paint paint = new Paint();
	paint.setColorFilter(new ColorMatrixColorFilter(matrix));
    c.drawBitmap(bmpOriginal, 0, 0, paint);
    return bmpFilter;
}

}	// ==> FIN