Переделай код, чтобы что в пороге растягивалась, что не в пороге не изменялось.
private void brightness1Image() {
if (image != null) {
int minThreshold = 50;
int maxThreshold = 50;

// Create panels for min and max threshold values
JPanel minThresholdPanel = new JPanel(new GridLayout(1, 2));
JPanel maxThresholdPanel = new JPanel(new GridLayout(1, 2));

// Create text fields for threshold values
JTextField minThresholdField = new JTextField(Integer.toString(minThreshold));
JTextField maxThresholdField = new JTextField(Integer.toString(maxThreshold));
minThresholdPanel.add(new JLabel("Min threshold: "));
maxThresholdPanel.add(new JLabel("Max threshold: "));
minThresholdPanel.add(minThresholdField);
maxThresholdPanel.add(maxThresholdField);

// Create window for inputting threshold values
int result = JOptionPane.showConfirmDialog(null, new Object[]{minThresholdPanel, maxThresholdPanel},
“Enter Threshold Values”, JOptionPane.OK_CANCEL_OPTION);

if (result == JOptionPane.OK_OPTION) {
// Update threshold values
minThreshold = Integer.parseInt(minThresholdField.getText());
maxThreshold = Integer.parseInt(maxThresholdField.getText());

// Create new image for modified image
BufferedImage modifiedImage = new BufferedImage(image.getWidth(), image.getHeight(), BufferedImage.TYPE_INT_RGB);

// Create color for black pixels
Color black = Color.BLACK;

for (int i = 0; i < image.getWidth(); i++) {
for (int j = 0; j < image.getHeight(); j++) {
// Get pixel and extract RGB values
int pixel = image.getRGB(i, j);
int red = (pixel >> 16) & 0xff;
int green = (pixel >> 8) & 0xff;
int blue = pixel & 0xff;

// Calculate brightness of pixel
int brightness = (int) (0.2126 * red + 0.7152 * green + 0.0722 * blue);

// Check if brightness value falls within threshold range
if (brightness >= minThreshold && brightness <= maxThreshold) {
Color c = new Color(red, green, blue);
modifiedImage.setRGB(i, j, c.getRGB());
} else {
modifiedImage.setRGB(i, j, black.getRGB());
}
}
}

if (modifiedImage != null) {
setImageIcon(modifiedImage);
saveImage(modifiedImage);

// Create histogram for original image
int[] originalHistogram = new int[256];
for (int i = 0; i < image.getWidth(); i++) {
for (int j = 0; j < image.getHeight(); j++) {
// Get pixel and extract RGB values
int pixel = image.getRGB(i, j);
int red = (pixel >> 16) & 0xff;
int green = (pixel >> 8) & 0xff;
int blue = pixel & 0xff;

// Calculate brightness of pixel
int brightness = (int) (0.2126 * red + 0.7152 * green + 0.0722 * blue);

originalHistogram[brightness]++;
}
}

// Create histogram for modified image
int[] modifiedHistogram = new int[256];
for (int i = 0; i < modifiedImage.getWidth(); i++) {
for (int j = 0; j < modifiedImage.getHeight(); j++) {
// Get pixel and extract RGB values
int pixel = modifiedImage.getRGB(i, j);
int red = (pixel >> 16) & 0xff;
int green = (pixel >> 8) & 0xff;
int blue = pixel & 0xff;

// Calculate brightness of pixel
int brightness = (int) (0.2126 * red + 0.7152 * green + 0.0722 * blue);

modifiedHistogram[brightness]++;
}
}

// Create window for displaying histograms
JFrame histogramFrame = new JFrame(“Histograms”);
histogramFrame.setLayout(new GridLayout(2, 2, 10, 10));

// Panel for original image histogram
JPanel originalHistogramPanel = new JPanel() {
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
int max = Arrays.stream(originalHistogram).max().getAsInt();
for (int i = 0; i < 256; i++) {
int height = (int) (300.0 * originalHistogram[i] / max);
g.fillRect(i, 300 - height, 1, height);
}
}
};
originalHistogramPanel.setBorder(BorderFactory.createLineBorder(Color.GRAY));
originalHistogramPanel.setPreferredSize(new Dimension(256, 300));
histogramFrame.add(new JLabel(“Original Image”));
histogramFrame.add(originalHistogramPanel);

// Panel for modified image histogram
JPanel modifiedHistogramPanel = new JPanel() {
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
int max = Arrays.stream(modifiedHistogram).max().getAsInt();
for (int i = 0; i < 256; i++) {
int height = (int) (300.0 * modifiedHistogram[i] / max);
g.fillRect(i, 300 - height, 1, height);
}
}
};
modifiedHistogramPanel.setBorder(BorderFactory.createLineBorder(Color.GRAY));
modifiedHistogramPanel.setPreferredSize(new Dimension(256, 300));
histogramFrame.add(new JLabel(“Modified Image”));
histogramFrame.add(modifiedHistogramPanel);

histogramFrame.pack();
histogramFrame.setLocationRelativeTo(null);
histogramFrame.setVisible(true);
}
}
}
}