减少颜色数量并获得单个像素的颜色

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问题描述

使用JavaFX 2.2我需要执行以下操作：

Using JavaFX 2.2 I need to do the following:

减少给定图像的颜色（例如使用JavaFX <$

访问图像对象中单个像素的颜色 - 确定，似乎 Image.getPixelReader（）应该执行此作业，因此只有第一个问题应该保留

Reduce the color of a given image (e.g. loaded using the JavaFX image class) to lets say 8 or 16 colors, or maybe 256 colors
Access the color of single pixels in the image object - OK, seems like Image.getPixelReader() should do the job, so only the first question should remain

任何人都可以给我一些提示或代码示例吗？感谢： - ）

Can anyone give me some hints or code examples on this? Thanks :-)

推荐答案

使用 image.getPixelReader（） code>获取访问图片中的各个像素。

 
 创建。
 
 取得。 
 
 迭代从像素读取器读取的像素，通过缩小算法为每个像素调色，并将缩小的像素写入像素写入器。

Use image.getPixelReader() to get a hold of the PixelReader to access individual pixels in the image.
Create a WritableImage.
Get the PixelWriter of the WritableImage.
Iterate through the pixels read from the pixel reader, run each pixel through a downscaling algorithm for it's color palette and write the downscaled pixel to the pixel writer.

完成后，您可以在或将其转换为和

After you have done this, you can display the downsampled WritableImage in an ImageView or convert it to an awt image and save it as a png, jpg, etc.

下面是一些示例代码：

import javafx.application.Application;
import javafx.event.*;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.scene.image.*;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

// displays a button with a 64 color image palette and a full color palette when pressed.
public class ButtonShadeTest extends Application {
  @Override public void start(final Stage stage) throws Exception {
    final Label response = new Label("");
    final Image originalImage = new Image("http://icons.iconarchive.com/icons/eponas-deeway/colobrush/128/heart-2-icon.png");
    final Image resampledImage = resample(originalImage);
    final ImageView imageView = new ImageView(resampledImage);
    final Button button = new Button("I love you", imageView);
    button.setStyle("-fx-base: coral;");
    button.setContentDisplay(ContentDisplay.TOP);
    button.setOnAction(new EventHandler<ActionEvent>() {
      @Override public void handle(ActionEvent event) {
        if ("".equals(response.getText())) {
          response.setText("I love you too!");
          imageView.setImage(originalImage);
        } else {
          response.setText("");
          imageView.setImage(resampledImage);
        }
      }
    });

    final VBox layout = new VBox(10);
    layout.setAlignment(Pos.CENTER);
    layout.getChildren().addAll(button, response);
    layout.setStyle("-fx-background-color: cornsilk; -fx-padding: 10; -fx-font-size: 20;");
    stage.setTitle("Heart");
    stage.getIcons().add(originalImage);
    stage.setScene(new Scene(layout));
    stage.show();
  }
  public static void main(String[] args) { launch(args); }

  // downsamples an image to a 64 color palette by only
  // using the 2 most significant bits of color to represent
  // each of the image's pixels.
  private Image resample(Image inputImage) {
    int W = (int) inputImage.getWidth();
    int H = (int) inputImage.getHeight();
    WritableImage outputImage = new WritableImage(W, H);
    PixelReader reader = inputImage.getPixelReader();
    PixelWriter writer = outputImage.getPixelWriter();
    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;

        r = r & 0xC0;
        g = g & 0xC0;
        b = b & 0xC0;

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

    return outputImage;
  }
}
// icon license: (creative commons with attribution) http://creativecommons.org/licenses/by-nc-nd/3.0/
// icon artist attribution page: (eponas-deeway) http://eponas-deeway.deviantart.com/gallery/#/d1s7uih

当心脏碎裂时，它会显示一个减少的调色板，当心脏是整体时，它会显示一个完整的调色板。

When the heart is broken it displays with a reduced color palette, when the heart is whole it displays with a full color palette.

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