image brightness slider Java

问题

i have:

BufferedImage image;
//few lines of code
public void stateChanged(ChangeEvent e) 
{
for (int i = 0; i < image.getWidth(); i++) {
        for (int j = 0; j < image.getHeight(); j++) 
        {
            Color color = new Color(image.getRGB(i, j));
            int r, g, b;
            val = sliderBrightness.getValue();
            r = color.getRed() + val;
            g = color.getGreen() + val;
            b = color.getBlue() + val;
        }
    }

I haven't got any idea how to solve this problem, what should i modify that Image will react on JSlider brightness?

回答1:

public void stateChanged(ChangeEvent e) 
{

for (int x = 0; x < image.getWidth(); x++) {
    for (int y = 0; y < image.getHeight(); y++) 
        {
        Color color = new Color(image.getRGB(x, y));

        int r, g, b;
        val = sliderBrightness.getValue();

        r = checkColorRange(color.getRed() + val);
        g = checkColorRange(color.getGreen() + val);
        b = checkColorRange(color.getBlue() + val);

        color = new Color(r, g, b);
        image.setRGB(x, y, color.getRGB());
        border.setIcon(new ImageIcon(image.getScaledInstance(350, 350, Image.SCALE_SMOOTH)));
        border.repaint();
        }
    }
}
public int checkColorRange(int newColor){
    if(newColor > 255){
        newColor = 255;
    } else if (newColor < 0) {
        newColor = 0;
    }
    return newColor;
}

Also you should use x and y, instead of i and j, for clarity.

回答2:

As shown here, use java.awt.image.RescaleOp to adjust the image's color bands as a function of the slider's position. Despite the name, AlphaTest, the example uses the constructor that applies "to all color (but not alpha) components in a BufferedImage."

来源：https://stackoverflow.com/questions/19606929/image-brightness-slider-java