安卓图像处理入门教程

第1章 图像处理概念介绍

1、RGBA模型分析

RGB:red,green,blue,alpha
色相：物体传递的颜色
饱和度：颜色的灰度，从0（灰）-100%

亮度：颜色的相对明暗程度

ColorMatrix
setRotate()
setSaturation()
setScale()
postConcat()

第2章 颜色矩阵变换与实例

图片中矩阵的作用通常用于初始化颜色矩阵

第3章 像素点分析与实例

1.使用getPixels()方法可获取图片的所有点的颜色值，一般采用以下格式：bitmap.getPixels(int[] ,0,width,0,0,width,height)。
参数说明：存放像素值的数组->最开始读取像素时的偏移量->行距(多少算作一行，一般去width)->(x,y)第一次读取参数的目标->要读取像素的长度->要读取像素的宽度

2.获取所有点的颜色值后，想对像素点进行操作，则需要一Color。red(color)方法读取R分量，G、B、Alpha分量类似。此处的color为之前存放在数组里的颜色值

3.处理RGB值之后，还需检查其是否依旧在(0,255)范围内

4.使用方法newPx[i] = Color.argb(a, r, g, b);将新的RGB值创造新的颜色值

5.使用bmp.setPixels(newPx, 0, width, 0, 0, width, height);将颜色值应用到图片上，返回图片

  r = Color.red(color);
        g = Color.green(color);
        b = Color.blue(color);
        a = Color.alpha(color);

底片

r = 255 - r;
g = 255 - g;
b = 255 - b;

老照片

r1 = (int) (0.393 * r + 0.769 * g + 0.189 * b);
        g1 = (int) (0.349 * r + 0.686 * g + 0.168 * b);
        b1 = (int) (0.272 * r + 0.534 * g + 0.131 * b);

浮雕

 r = (r - r1 + 127);
    g = (g - g1 + 127);
    b = (b - b1 + 127);

ImageHelper工具类

public class ImageHelper {
public static Bitmap handleImageEffect(Bitmap bm, float hue, float saturation, float lum) {
    Bitmap bmp=Bitmap.createBitmap(bm.getWidth(),bm.getHeight(),Bitmap.Config.ARGB_8888);
    Canvas canvas=new Canvas(bmp);
    Paint paint=new Paint(Paint.ANTI_ALIAS_FLAG);

    ColorMatrix hueMatrix=new ColorMatrix();
    hueMatrix.setRotate(0,hue);
    hueMatrix.setRotate(1, hue);
    hueMatrix.setRotate(2, hue);

    ColorMatrix saturationMatrix=new ColorMatrix();
    saturationMatrix.setSaturation(saturation);

    ColorMatrix lumMatrix=new ColorMatrix();
    lumMatrix.setScale(lum,lum,lum,1);

    ColorMatrix imageMatrix=new ColorMatrix();
    imageMatrix.postConcat(hueMatrix);
    imageMatrix.postConcat(saturationMatrix);
    imageMatrix.postConcat(lumMatrix);

    paint.setColorFilter(new ColorMatrixColorFilter(imageMatrix));
    canvas.drawBitmap(bm,0,0,paint);

    return bmp;
}
public static Bitmap handleImageNegative(Bitmap bm){
    int width = bm.getWidth();
    int height = bm.getHeight();
    int color;
    int r, g, b, a;

    Bitmap bmp = Bitmap.createBitmap(width, height
            , Bitmap.Config.ARGB_8888);

    int[] oldPx = new int[width * height];
    int[] newPx = new int[width * height];
    bm.getPixels(oldPx, 0, width, 0, 0, width, height);

    for (int i = 0; i < width * height; i++) {
        color = oldPx[i];
        r = Color.red(color);
        g = Color.green(color);
        b = Color.blue(color);
        a = Color.alpha(color);

        r = 255 - r;
        g = 255 - g;
        b = 255 - b;

        if (r > 255) {
            r = 255;
        } else if (r < 0) {
            r = 0;
        }
        if (g > 255) {
            g = 255;
        } else if (g < 0) {
            g = 0;
        }
        if (b > 255) {
            b = 255;
        } else if (b < 0) {
            b = 0;
        }
        newPx[i] = Color.argb(a, r, g, b);
    }
    bmp.setPixels(newPx, 0, width, 0, 0, width, height);
    return bmp;
}

public static Bitmap handleImagePixelsoldPhoto(Bitmap bm) {
    Bitmap bmp = Bitmap.createBitmap(bm.getWidth(), bm.getHeight(),
            Bitmap.Config.ARGB_8888);
    int width = bm.getWidth();
    int height = bm.getHeight();
    int color = 0;
    int r, g, b, a, r1, g1, b1;

    int[] oldPx = new int[width * height];
    int[] newPx = new int[width * height];

    bm.getPixels(oldPx, 0, bm.getWidth(), 0, 0, width, height);
    for (int i = 0; i < width * height; i++) {
        color = oldPx[i];
        a = Color.alpha(color);
        r = Color.red(color);
        g = Color.green(color);
        b = Color.blue(color);

        r1 = (int) (0.393 * r + 0.769 * g + 0.189 * b);
        g1 = (int) (0.349 * r + 0.686 * g + 0.168 * b);
        b1 = (int) (0.272 * r + 0.534 * g + 0.131 * b);

        if (r1 > 255) {
            r1 = 255;
        }
        if (g1 > 255) {
            g1 = 255;
        }
        if (b1 > 255) {
            b1 = 255;
        }

        newPx[i] = Color.argb(a, r1, g1, b1);
    }
    bmp.setPixels(newPx, 0, width, 0, 0, width, height);
    return bmp;
}

public static Bitmap handleImagePixelsRelief(Bitmap bm) {
Bitmap bmp = Bitmap.createBitmap(bm.getWidth(), bm.getHeight(),
        Bitmap.Config.ARGB_8888);
int width = bm.getWidth();
int height = bm.getHeight();
int color = 0, colorBefore = 0;
int a, r, g, b;
int r1, g1, b1;

int[] oldPx = new int[width * height];
int[] newPx = new int[width * height];

bm.getPixels(oldPx, 0, bm.getWidth(), 0, 0, width, height);
for (int i = 1; i < width * height; i++) {
    colorBefore = oldPx[i - 1];
    a = Color.alpha(colorBefore);
    r = Color.red(colorBefore);
    g = Color.green(colorBefore);
    b = Color.blue(colorBefore);

    color = oldPx[i];
    r1 = Color.red(color);
    g1 = Color.green(color);
    b1 = Color.blue(color);

    r = (r - r1 + 127);
    g = (g - g1 + 127);
    b = (b - b1 + 127);
    if (r > 255) {
        r = 255;
    }
    if (g > 255) {
        g = 255;
    }
    if (b > 255) {
        b = 255;
    }
    newPx[i] = Color.argb(a, r, g, b);
}
bmp.setPixels(newPx, 0, width, 0, 0, width, height);
return bmp;
}
}