How to change image color in JavaFX

Question

I have a PNG image:

I want to change the image to something like this:

How to do it in JavaFX?

Answer 1

As you do not care if it is a vector shape or a bitmap, I will simply describe the solutions using the bitmap here. If you really need a vector shape, I believe that you will need to work with vector input to get a good result.

---

Use the ColorAdjust effect with the minimum set to (-1). Download the result for SPEED.

Here is an example that creates a shadow outline of an image:

import javafx.application.Application;
import javafx.scene.*;
import javafx.scene.effect.ColorAdjust;
import javafx.scene.image.*;
import javafx.stage.Stage;

public class Shadow extends Application {
    @Override 
    public void start(Stage stage) throws Exception {
        ImageView imageView = new ImageView(
            new Image(
                "http://i.stack.imgur.com/jbT1H.png"
            )
        );

        ColorAdjust blackout = new ColorAdjust();
        blackout.setBrightness(-1.0);

        imageView.setEffect(blackout);
        imageView.setCache(true);
        imageView.setCacheHint(CacheHint.SPEED);

        stage.setScene(new Scene(new Group(imageView)));
        stage.show();
    }

    public static void main(String[] args) {
        Application.launch();
    }
}

, , smurfette, .

import javafx.application.Application;
import javafx.beans.binding.Bindings;
import javafx.scene.*;
import javafx.scene.effect.*;
import javafx.scene.image.*;
import javafx.scene.paint.Color;
import javafx.stage.Stage;

public class Shadow extends Application {
    @Override
    public void start(Stage stage) throws Exception {
        Image image = new Image(
                "http://icons.iconarchive.com/icons/designbolts/smurfs-movie/128/smurfette-icon.png"
        );

        ImageView imageView = new ImageView(image);
        imageView.setClip(new ImageView(image));

        ColorAdjust monochrome = new ColorAdjust();
        monochrome.setSaturation(-1.0);

        Blend blush = new Blend(
                BlendMode.MULTIPLY,
                monochrome,
                new ColorInput(
                        0,
                        0,
                        imageView.getImage().getWidth(),
                        imageView.getImage().getHeight(),
                        Color.RED
                )
        );

        imageView.effectProperty().bind(
                Bindings
                    .when(imageView.hoverProperty())
                        .then((Effect) blush)
                        .otherwise((Effect) null)
        );

        imageView.setCache(true);
        imageView.setCacheHint(CacheHint.SPEED);

        stage.setScene(new Scene(new Group(imageView), Color.AQUA));
        stage.show();
    }

    public static void main(String[] args) {
        Application.launch();
    }
}

Answer 2

. , , . , .

/**
   * reColor the given InputImage to the given color
   * inspired by https://stackoverflow.com/a/12945629/1497139
   * @param inputImage
   * @param oldColor
   * @param newColor 
   * @return reColored Image
   * 
   */
  public static Image reColor(Image inputImage, Color oldColor, Color newColor) {
    int W = (int) inputImage.getWidth();
    int H = (int) inputImage.getHeight();
    WritableImage outputImage = new WritableImage(W, H);
    PixelReader reader = inputImage.getPixelReader();
    PixelWriter writer = outputImage.getPixelWriter();
    int ob=(int) oldColor.getBlue()*255;
    int or=(int) oldColor.getRed()*255;
    int og=(int) oldColor.getGreen()*255;
    int nb=(int) newColor.getBlue()*255;
    int nr=(int) newColor.getRed()*255;
    int ng=(int) newColor.getGreen()*255;
    for (int y = 0; y < H; y++) {
      for (int x = 0; x < W; x++) {
        int argb = reader.getArgb(x, y);
        int a = (argb >> 24) & 0xFF;
        int r = (argb >> 16) & 0xFF;
        int g = (argb >>  8) & 0xFF;
        int b =  argb        & 0xFF;
        if (g==og && r==or && b==ob) {
          r=nr;
          g=ng;
          b=nb;
        }

        argb = (a << 24) | (r << 16) | (g << 8) | b;
        writer.setArgb(x, y, argb);
      }
    }
    return outputImage;
  }