Java 之 获取图片主色调

public class RGB {

    private int red;

    private int green;

    private int blue;

    public RGB(){}

    public RGB(int red,int green,int blue){
        setRed(red);
        setBlue(blue);
        setGreen(green);
    }

    public int getRed() {
        return red;
    }

    public void setRed(int red) {
        if (red < 0) {
            this.red = 0;
        } else if (red > 255) {
            this.red = 255;
        } else {
            this.red = red;
        }
    }

    public int getGreen() {
        return green;
    }

    public void setGreen(int green) {
        if (green < 0) {
            this.green = 0;
        } else if (green > 255) {
            this.green = 255;
        } else {
            this.green = green;
        }
    }

    public int getBlue() {
        return blue;
    }

    public void setBlue(int blue) {
        if (blue < 0) {
            this.blue = 0;
        } else if (blue > 255) {
            this.blue = 255;
        } else {
            this.blue = blue;
        }
    }

    @Override
    public boolean equals(Object obj) {
        RGB theRGB = (RGB) obj;
        return this.getRed() == theRGB.getRed() && this.getGreen() == theRGB.getGreen() && this.getBlue() == theRGB.getBlue();
    }

    @Override
    public int hashCode() {
        return this.getRed() * 1000000 + this.getGreen() * 1000 + this.getBlue();
    }

    public String toString() {
        return "RGB {" + this.red + ", " + this.green + ", " + this.blue + "}";
    }

}

public class HSL {

    private float h;
    /** 饱和度 */
    private float s;
    /** 深度 */
    private float l;

    public HSL() {
    }

    public HSL(float h, float s, float l) {
        setH(h);
        setS(s);
        setL(l);
    }

    public float getH() {
        return h;
    }

    public void setH(float h) {
        if (h < 0) {
            this.h = 0;
        } else if (h > 360) {
            this.h = 360;
        } else {
            this.h = h;
        }
    }

    public float getS() {
        return s;
    }

    public void setS(float s) {
        if (s < 0) {
            this.s = 0;
        } else if (s > 255) {
            this.s = 255;
        } else {
            this.s = s;
        }
    }

    public float getL() {
        return l;
    }

    public void setL(float l) {
        if (l < 0) {
            this.l = 0;
        } else if (l > 255) {
            this.l = 255;
        } else {
            this.l = l;
        }
    }

    @Override
    public boolean equals(Object obj) {
        HSL theHSL = (HSL) obj;
        return this.getH() == theHSL.getH() && this.getS() == theHSL.getS() && this.getL() == theHSL.getL();
    }

    @Override
    public int hashCode() {
        return Float.valueOf(this.getH() * 1000000 + this.getS() * 1000 + this.getL()).intValue();
    }

    public String toString() {
        return "HSL {" + h + ", " + s + ", " + l + "}";
    }

}

public class ColorConverter {

    /**
     * @param rgb
     * @return
     */
    public static HSL RGB2HSL(RGB rgb) {
        if (rgb == null) {
            return null;
        }
        int red = rgb.getRed();
        int green = rgb.getGreen();
        int blue = rgb.getBlue();
        float var_Min = Math.min(red, Math.min(blue, green));
        float var_Max = Math.max(red, Math.max(blue, green));
        float del_Max = var_Max - var_Min;
        float H = 0;
        float S = 0;
        float L = (var_Max + var_Min) / 2;
        if (del_Max == 0) {
            H = 0;
            S = 0;
        } else {
            if (L < 128) {
                S = 256 * del_Max / (var_Max + var_Min);
            } else {
                S = 256 * del_Max / (512 - var_Max - var_Min);
            }
            float del_R = ((360 * (var_Max - red) / 6) + (360 * del_Max / 2))
                    / del_Max;
            float del_G = ((360 * (var_Max - green) / 6) + (360 * del_Max / 2))
                    / del_Max;
            float del_B = ((360 * (var_Max - blue) / 6) + (360 * del_Max / 2))
                    / del_Max;
            if (red == var_Max) {
                H = del_B - del_G;
            } else if (green == var_Max) {
                H = 120 + del_R - del_B;
            } else if (blue == var_Max) {
                H = 240 + del_G - del_R;
            }
            if (H < 0) {
                H += 360;
            }
            if (H >= 360) {
                H -= 360;
            }
            if (L >= 256) {
                L = 255;
            }
            if (S >= 256) {
                S = 255;
            }
        }
        return new HSL(H, S, L);
    }

    /**
     * @param hsl
     * @return
     */
    public static RGB HSL2RGB(HSL hsl) {
        if (hsl == null) {
            return null;
        }
        float H = hsl.getH();
        float S = hsl.getS();
        float L = hsl.getL();

        float R, G, B, var_1, var_2;
        if (S == 0) {
            R = L;
            G = L;
            B = L;
        } else {
            if (L < 128) {
                var_2 = (L * (256 + S)) / 256;
            } else {
                var_2 = (L + S) - (S * L) / 256;
            }
            if (var_2 > 255) {
                var_2 = Math.round(var_2);
            }
            if (var_2 > 254) {
                var_2 = 255;
            }
            var_1 = 2 * L - var_2;
            R = RGBFromHue(var_1, var_2, H + 120);
            G = RGBFromHue(var_1, var_2, H);
            B = RGBFromHue(var_1, var_2, H - 120);
        }
        R = R < 0 ? 0 : R;
        R = R > 255 ? 255 : R;
        G = G < 0 ? 0 : G;
        G = G > 255 ? 255 : G;
        B = B < 0 ? 0 : B;
        B = B > 255 ? 255 : B;
        return new RGB((int) Math.round(R), (int) Math.round(G), (int) Math.round(B));
    }

    /**
     * @param a
     * @param b
     * @param h
     * @return
     */
    public static float RGBFromHue(float a, float b, float h) {
        if (h < 0) {
            h += 360;
        }
        if (h >= 360) {
            h -= 360;
        }
        if (h < 60) {
            return a + ((b - a) * h) / 60;
        }
        if (h < 180) {
            return b;
        }
        if (h < 240) {
            return a + ((b - a) * (240 - h)) / 60;
        }
        return a;
    }

}

public class HslTest {

    /**
     * 获取图片主色调的rgb值
     * @param path
     * @return
     * @throws Exception
     */
    public static RGB getMainRgb (String path) throws Exception{
        Map<Float, Integer> hueCountMap = new HashMap<>();
        Map<HSL, Integer> hslCountMap = new HashMap<>();
        BufferedImage image = ImageIO.read(new URL(path));
//        BufferedImage image = ImageIO.read(new File(path));
        int width = image.getWidth();
        int height = image.getHeight();
        int minx = image.getMinX();
        int miny = image.getMinY();
        //计算各点的hsl值，并统计数量
        for (int i = minx; i < width; i++) {
            for (int j = miny; j < height; j++) {
                int pixel = image.getRGB(i, j);
                Color color = new Color(pixel);
                RGB rgb = new RGB(color.getRed(), color.getGreen(), color.getBlue());
                HSL hsl = ColorConverter.RGB2HSL(rgb);
                float h = computeHue(hsl.getH());
                float s = computeSAndL(hsl.getS());
                float l = computeSAndL(hsl.getL());
                HSL newHSL = new HSL(h, s, l);
                //统计hue值数量
                Integer count = hueCountMap.get(h);
                if(count == null){
                    hueCountMap.put(h, 1);
                }else{
                    hueCountMap.put(h, count + 1);
                }
                //统计HSL数量
                count = hslCountMap.get(newHSL);
                if(count == null){
                    hslCountMap.put(newHSL, 1);
                }else{
                    hslCountMap.put(newHSL, count + 1);
                }
            }
        }
        //查找数量最多的hue值
        float maxHue = 0;
        int maxCount = 0;
        for(Map.Entry<Float, Integer> entry : hueCountMap.entrySet()){
            float hue = entry.getKey();
            int count = entry.getValue();
            if(count > maxCount){
                maxCount = count;
                maxHue = hue;
            }
        }
        //查找maxHue中数量最多的hsl值
        HSL maxHSL = null;
        maxCount = 0;
        for(Map.Entry<HSL, Integer> entry : hslCountMap.entrySet()){
            HSL hsl = entry.getKey();
            int count = entry.getValue();
            if(hsl.getH() == maxHue && count > maxCount){
                maxCount = count;
                maxHSL = hsl;
            }
        }
        //hsl转rgb
        RGB resultRGB = ColorConverter.HSL2RGB(maxHSL);
        return resultRGB;
    }

    /**
     * 按格子划分h值
     * @param h
     * @return
     */
    public static float computeHue (float h){
        if(h <= 15){
            return 0;
        }
        if(15 < h && h <= 45){
            return 30;
        }
        if(45 < h && h <= 75){
            return 60;
        }
        if(75 < h && h <= 105){
            return 90;
        }
        if(105 < h && h <= 135){
            return 120;
        }
        if(135 < h && h <= 165){
            return 150;
        }
        if(165 < h && h <= 195){
            return 180;
        }
        if(195 < h && h <= 225){
            return 210;
        }
        if(225 < h && h <= 255){
            return 240;
        }
        if(255 < h && h <= 285){
            return 270;
        }
        if(285 < h && h <= 315){
            return 300;
        }
        if(315 < h && h <= 345){
            return 330;
        }
        if(345 < h){
            return 360;
        }
        return 360;
    }

    /**
     * 按格子划分s和l值
     * @param s
     * @return
     */
    public static float computeSAndL (float s){
        if(s <= 32){
            return 0;
        }
        if(32 < s && s <= 96){
            return 64;
        }
        if(96 < s && s <= 160){
            return 128;
        }
        if(160 < s && s <= 224){
            return 192;
        }
        if(s > 224){
            return 255;
        }
        return 255;
    }

}

public static void main(String[] args) throws Exception {
        String path = "http://b-ssl.duitang.com/uploads/item/201805/19/20180519081907_wflza.jpg";
        RGB rgb = HslTest.getMainRgb(path);
        System.out.println(rgb);
    }