彩色图片转黑白

//image 转 BufferedImage
public static BufferedImage toBufferedImage(Image image) {
if (image instanceof BufferedImage) {
return (BufferedImage)image;
}

// This code ensures that all the pixels in the image are loaded
image = new ImageIcon(image).getImage();

// Determine if the image has transparent pixels; for this method's
// implementation, see e661 Determining If an Image Has Transparent Pixels
//boolean hasAlpha = hasAlpha(image);

// Create a buffered image with a format that's compatible with the screen
BufferedImage bimage = null;
GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
try {
// Determine the type of transparency of the new buffered image
int transparency = Transparency.OPAQUE;
/* if (hasAlpha) {
transparency = Transparency.BITMASK;
}*/

// Create the buffered image
GraphicsDevice gs = ge.getDefaultScreenDevice();
GraphicsConfiguration gc = gs.getDefaultConfiguration();
bimage = gc.createCompatibleImage(
image.getWidth(null), image.getHeight(null), transparency);
} catch (HeadlessException e) {
// The system does not have a screen
}

if (bimage == null) {
// Create a buffered image using the default color model
int type = BufferedImage.TYPE_INT_RGB;
//int type = BufferedImage.TYPE_3BYTE_BGR;//by wang
/*if (hasAlpha) {
type = BufferedImage.TYPE_INT_ARGB;
}*/
bimage = new BufferedImage(image.getWidth(null), image.getHeight(null), type);
}

// Copy image to buffered image
Graphics g = bimage.createGraphics();

// Paint the image onto the buffered image
g.drawImage(image, 0, 0, null);
g.dispose();

return bimage;
}
//彩色图片转黑白
    public static void main(String[] args) {
        BufferedImage image;
        try {
            image = ImageIO.read(new File ("C:\\Users\\amssy\\Desktop\\3.jpeg"));
            
            image = OCRUtil.grayImage(image);
            File file = new File ("C:\\Users\\amssy\\Desktop\\3n.jpeg");
            ImageIO.write(image, "jpeg", file);
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

     public static BufferedImage grayImage(final BufferedImage srcImg) {

            int width = srcImg.getWidth();

            int height = srcImg.getHeight();

            int[] pixels = new int[width * height];

            srcImg.getRGB(0, 0, width, height, pixels, 0, width);

            int newPixels[] = new int[width * height];

            for(int i = 0; i < width * height; i++) {

                HSLColor hslColor = new HSLColor(HSLColor.fromRGB(new Color(pixels[i])));

                newPixels[i] = hslColor.adjustSaturation(0).getRGB();

            }

            BufferedImage bi = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

            bi.setRGB(0, 0, width, height, newPixels, 0, width);

            return bi;

        }

//工具类

package util;

import java.awt.Color;

/**
* The HSLColor class provides methods to manipulate HSL (Hue, Saturation
* Luminance) values to create a corresponding Color object using the RGB
* ColorSpace.
*
* The HUE is the color, the Saturation is the purity of the color (with
* respect to grey) and Luminance is the brightness of the color (with respect
* to black and white)
*
* The Hue is specified as an angel between 0 - 360 degrees where red is 0,
* green is 120 and blue is 240. In between you have the colors of the rainbow.
* Saturation is specified as a percentage between 0 - 100 where 100 is fully
* saturated and 0 approaches gray. Luminance is specified as a percentage
* between 0 - 100 where 0 is black and 100 is white.
*
* In particular the HSL color space makes it easier change the Tone or Shade
* of a color by adjusting the luminance value.
*/
public class HSLColor
{
private Color rgb;
private float[] hsl;
private float alpha;

/**
* Create a HSLColor object using an RGB Color object.
*
* @param rgb the RGB Color object
*/
public HSLColor(Color rgb)
{
this.rgb = rgb;
hsl = fromRGB( rgb );
alpha = rgb.getAlpha() / 255.0f;
}

/**
* Create a HSLColor object using individual HSL values and a default
* alpha value of 1.0.
*
* @param h is the Hue value in degrees between 0 - 360
* @param s is the Saturation percentage between 0 - 100
* @param l is the Lumanance percentage between 0 - 100
*/
public HSLColor(float h, float s, float l)
{
this(h, s, l, 1.0f);
}

/**
* Create a HSLColor object using individual HSL values.
*
* @param h the Hue value in degrees between 0 - 360
* @param s the Saturation percentage between 0 - 100
* @param l the Lumanance percentage between 0 - 100
* @param alpha the alpha value between 0 - 1
*/
public HSLColor(float h, float s, float l, float alpha)
{
hsl = new float[] {h, s, l};
this.alpha = alpha;
rgb = toRGB(hsl, alpha);
}

/**
* Create a HSLColor object using an an array containing the
* individual HSL values and with a default alpha value of 1.
*
* @param hsl array containing HSL values
*/
public HSLColor(float[] hsl)
{
this(hsl, 1.0f);
}

/**
* Create a HSLColor object using an an array containing the
* individual HSL values.
*
* @param hsl array containing HSL values
* @param alpha the alpha value between 0 - 1
*/
public HSLColor(float[] hsl, float alpha)
{
this.hsl = hsl;
this.alpha = alpha;
rgb = toRGB(hsl, alpha);
}

/**
* Create a RGB Color object based on this HSLColor with a different
* Hue value. The degrees specified is an absolute value.
*
* @param degrees - the Hue value between 0 - 360
* @return the RGB Color object
*/
public Color adjustHue(float degrees)
{
return toRGB(degrees, hsl[1], hsl[2], alpha);
}

/**
* Create a RGB Color object based on this HSLColor with a different
* Luminance value. The percent specified is an absolute value.
*
* @param percent - the Luminance value between 0 - 100
* @return the RGB Color object
*/
public Color adjustLuminance(float percent)
{
return toRGB(hsl[0], hsl[1], percent, alpha);
}

/**
* Create a RGB Color object based on this HSLColor with a different
* Saturation value. The percent specified is an absolute value.
*
* @param percent - the Saturation value between 0 - 100
* @return the RGB Color object
*/
public Color adjustSaturation(float percent)
{
return toRGB(hsl[0], percent, hsl[2], alpha);
}

/**
* Create a RGB Color object based on this HSLColor with a different
* Shade. Changing the shade will return a darker color. The percent
* specified is a relative value.
*
* @param percent - the value between 0 - 100
* @return the RGB Color object
*/
public Color adjustShade(float percent)
{
float multiplier = (100.0f - percent) / 100.0f;
float l = Math.max(0.0f, hsl[2] * multiplier);

return toRGB(hsl[0], hsl[1], l, alpha);
}

/**
* Create a RGB Color object based on this HSLColor with a different
* Tone. Changing the tone will return a lighter color. The percent
* specified is a relative value.
*
* @param percent - the value between 0 - 100
* @return the RGB Color object
*/
public Color adjustTone(float percent)
{
float multiplier = (100.0f + percent) / 100.0f;
float l = Math.min(100.0f, hsl[2] * multiplier);

return toRGB(hsl[0], hsl[1], l, alpha);
}

/**
* Get the Alpha value.
*
* @return the Alpha value.
*/
public float getAlpha()
{
return alpha;
}

/**
* Create a RGB Color object that is the complementary color of this
* HSLColor. This is a convenience method. The complementary color is
* determined by adding 180 degrees to the Hue value.
* @return the RGB Color object
*/
public Color getComplementary()
{
float hue = (hsl[0] + 180.0f) % 360.0f;
return toRGB(hue, hsl[1], hsl[2]);
}

/**
* Get the Hue value.
*
* @return the Hue value.
*/
public float getHue()
{
return hsl[0];
}

/**
* Get the HSL values.
*
* @return the HSL values.
*/
public float[] getHSL()
{
return hsl;
}

/**
* Get the Luminance value.
*
* @return the Luminance value.
*/
public float getLuminance()
{
return hsl[2];
}

/**
* Get the RGB Color object represented by this HDLColor.
*
*
4000
@return the RGB Color object.
*/
public Color getRGB()
{
return rgb;
}

/**
* Get the Saturation value.
*
* @return the Saturation value.
*/
public float getSaturation()
{
return hsl[1];
}

public String toString()
{
String toString =
"HSLColor[h=" + hsl[0] +
",s=" + hsl[1] +
",l=" + hsl[2] +
",alpha=" + alpha + "]";

return toString;
}

/**
* Convert a RGB Color to it corresponding HSL values.
*
* @return an array containing the 3 HSL values.
*/
public static float[] fromRGB(Color color)
{
// Get RGB values in the range 0 - 1

float[] rgb = color.getRGBColorComponents( null );
float r = rgb[0];
float g = rgb[1];
float b = rgb[2];

// Minimum and Maximum RGB values are used in the HSL calculations

float min = Math.min(r, Math.min(g, b));
float max = Math.max(r, Math.max(g, b));

// Calculate the Hue

float h = 0;

if (max == min)
h = 0;
else if (max == r)
h = ((60 * (g - b) / (max - min)) + 360) % 360;
else if (max == g)
h = (60 * (b - r) / (max - min)) + 120;
else if (max == b)
h = (60 * (r - g) / (max - min)) + 240;

// Calculate the Luminance

float l = (max + min) / 2;

// Calculate the Saturation

float s = 0;

if (max == min)
s = 0;
else if (l <= .5f)
s = (max - min) / (max + min);
else
s = (max - min) / (2 - max - min);

return new float[] {h, s * 100, l * 100};
}

/**
* Convert HSL values to a RGB Color with a default alpha value of 1.
* H (Hue) is specified as degrees in the range 0 - 360.
* S (Saturation) is specified as a percentage in the range 1 - 100.
* L (Lumanance) is specified as a percentage in the range 1 - 100.
*
* @param hsl an array containing the 3 HSL values
*
* @returns the RGB Color object
*/
public static Color toRGB(float[] hsl)
{
return toRGB(hsl, 1.0f);
}

/**
* Convert HSL values to a RGB Color.
* H (Hue) is specified as degrees in the range 0 - 360.
* S (Saturation) is specified as a percentage in the range 1 - 100.
* L (Lumanance) is specified as a percentage in the range 1 - 100.
*
* @param hsl an array containing the 3 HSL values
* @param alpha the alpha value between 0 - 1
*
* @returns the RGB Color object
*/
public static Color toRGB(float[] hsl, float alpha)
{
return toRGB(hsl[0], hsl[1], hsl[2], alpha);
}

/**
* Convert HSL values to a RGB Color with a default alpha value of 1.
*
* @param h Hue is specified as degrees in the range 0 - 360.
* @param s Saturation is specified as a percentage in the range 1 - 100.
* @param l Lumanance is specified as a percentage in the range 1 - 100.
*
* @returns the RGB Color object
*/
public static Color toRGB(float h, float s, float l)
{
return toRGB(h, s, l, 1.0f);
}

/**
* Convert HSL values to a RGB Color.
*
* @param h Hue is specified as degrees in the range 0 - 360.
* @param s Saturation is specified as a percentage in the range 1 - 100.
* @param l Lumanance is specified as a percentage in the range 1 - 100.
* @param alpha the alpha value between 0 - 1
*
* @returns the RGB Color object
*/
public static Color toRGB(float h, float s, float l, float alpha)
{
if (s <0.0f || s > 100.0f)
{
String message = "Color parameter outside of expected range - Saturation";
throw new IllegalArgumentException( message );
}

if (l <0.0f || l > 100.0f)
{
String message = "Color parameter outside of expected range - Luminance";
throw new IllegalArgumentException( message );
}

if (alpha <0.0f || alpha > 1.0f)
{
String message = "Color parameter outside of expected range - Alpha";
throw new IllegalArgumentException( message );
}

// Formula needs all values between 0 - 1.

h = h % 360.0f;
h /= 360f;
s /= 100f;
l /= 100f;

float q = 0;

if (l < 0.5)
q = l * (1 + s);
else
q = (l + s) - (s * l);

float p = 2 * l - q;

float r = Math.max(0, HueToRGB(p, q, h + (1.0f / 3.0f)));
float g = Math.max(0, HueToRGB(p, q, h));
float b = Math.max(0, HueToRGB(p, q, h - (1.0f / 3.0f)));

r = Math.min(r, 1.0f);
g = Math.min(g, 1.0f);
b = Math.min(b, 1.0f);

return new Color(r, g, b, alpha);
}

private static float HueToRGB(float p, float q, float h)
{
if (h < 0) h += 1;

if (h > 1 ) h -= 1;

if (6 * h < 1)
{
return p + ((q - p) * 6 * h);
}

if (2 * h < 1 )
{
return q;
}

if (3 * h < 2)
{
return p + ( (q - p) * 6 * ((2.0f / 3.0f) - h) );
}

return p;
}
}