get Sketched Bitmap - Android Graphics

Description

get Sketched Bitmap

Demo Code

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Bitmap.CompressFormat;
import android.graphics.Bitmap.Config;
import android.graphics.BitmapFactory;
import android.graphics.BitmapFactory.Options;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.LinearGradient;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PixelFormat;
import android.graphics.PorterDuff.Mode;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.RectF;
import android.graphics.Shader.TileMode;
import android.graphics.YuvImage;
import android.graphics.drawable.Drawable;

public class Main{
    /*from w w w. jav a  2s . c om*/

    private static final String TAG = ImgUtil.class.getSimpleName();
    
    public static Bitmap getSketchedBitmap(Bitmap src, float ratio,
            boolean recycleSrc) {
        Bitmap sketched = sketchBitmap(src.copy(Config.RGB_565, true),
                ratio);
        if (recycleSrc && sketched != src) {
            src.recycle();
        }
        return sketched;
    }
    
    public static Bitmap sketchBitmap(Bitmap src, float ratio) {
        if (!src.isMutable()) {
            LogUtil.w(TAG, "sketchBitmap", "source bitmap is not mutable");
            return src;
        }

        int pos, row, col, clr;
        int width = src.getWidth();
        int height = src.getHeight();
        int[] pixSrc = new int[width * height];
        int[] pixNvt = new int[width * height];
        src.getPixels(pixSrc, 0, width, 0, 0, width, height);

        // ?
        for (row = 0; row < height; ++row) {
            for (col = 0; col < width; ++col) {
                pos = row * width + col;
                pixSrc[pos] = (Color.red(pixSrc[pos])
                        + Color.green(pixSrc[pos]) + Color
                        .blue(pixSrc[pos])) / 3;
                pixNvt[pos] = 255 - pixSrc[pos];
            }
        }

        // ?
        gaussGray(pixNvt, ratio, ratio, width, height);

        // ?
        for (row = 0; row < height; ++row) {
            for (col = 0; col < width; ++col) {
                pos = row * width + col;
                clr = pixSrc[pos] << 8;
                clr /= 256 - pixNvt[pos];
                clr = Math.min(clr, 255);
                pixSrc[pos] = Color.rgb(clr, clr, clr);
            }
        }

        src.setPixels(pixSrc, 0, width, 0, 0, width, height);
        return src;
    }
    private static int gaussGray(int[] psrc, double horz, double vert,
            int width, int height) {
        int[] dst, src;
        double[] n_p, n_m, d_p, d_m, bd_p, bd_m;
        double[] val_p, val_m;
        int i, j, t, k, row, col, terms;
        int[] initial_p, initial_m;
        double std_dev;
        int row_stride = width;
        int max_len = Math.max(width, height);
        int sp_p_idx, sp_m_idx, vp_idx, vm_idx;

        val_p = new double[max_len];
        val_m = new double[max_len];

        n_p = new double[5];
        n_m = new double[5];
        d_p = new double[5];
        d_m = new double[5];
        bd_p = new double[5];
        bd_m = new double[5];

        src = new int[max_len];
        dst = new int[max_len];

        initial_p = new int[4];
        initial_m = new int[4];

        // 
        if (vert > 0.0) {
            vert = Math.abs(vert) + 1.0;
            std_dev = Math.sqrt(-(vert * vert)
                    / (2 * Math.log(1.0 / 255.0)));

            // ?
            findConstants(n_p, n_m, d_p, d_m, bd_p, bd_m, std_dev);

            for (col = 0; col < width; col++) {
                for (k = 0; k < max_len; k++) {
                    val_m[k] = val_p[k] = 0;
                }

                for (t = 0; t < height; t++) {
                    src[t] = psrc[t * row_stride + col];
                }

                sp_p_idx = 0;
                sp_m_idx = height - 1;
                vp_idx = 0;
                vm_idx = height - 1;

                initial_p[0] = src[0];
                initial_m[0] = src[height - 1];

                for (row = 0; row < height; row++) {
                    terms = (row < 4) ? row : 4;

                    for (i = 0; i <= terms; i++) {
                        val_p[vp_idx] += n_p[i] * src[sp_p_idx - i]
                                - d_p[i] * val_p[vp_idx - i];
                        val_m[vm_idx] += n_m[i] * src[sp_m_idx + i]
                                - d_m[i] * val_m[vm_idx + i];
                    }
                    for (j = i; j <= 4; j++) {
                        val_p[vp_idx] += (n_p[j] - bd_p[j]) * initial_p[0];
                        val_m[vm_idx] += (n_m[j] - bd_m[j]) * initial_m[0];
                    }

                    sp_p_idx++;
                    sp_m_idx--;
                    vp_idx++;
                    vm_idx--;
                }

                transferGaussPixels(val_p, val_m, dst, 1, height);

                for (t = 0; t < height; t++) {
                    psrc[t * row_stride + col] = dst[t];
                }
            }
        }

        // 
        if (horz > 0.0) {
            horz = Math.abs(horz) + 1.0;

            if (horz != vert) {
                std_dev = Math.sqrt(-(horz * horz)
                        / (2 * Math.log(1.0 / 255.0)));

                // ?
                findConstants(n_p, n_m, d_p, d_m, bd_p, bd_m, std_dev);
            }

            for (row = 0; row < height; row++) {
                for (k = 0; k < max_len; k++) {
                    val_m[k] = val_p[k] = 0;
                }

                for (t = 0; t < width; t++) {
                    src[t] = psrc[row * row_stride + t];
                }

                sp_p_idx = 0;
                sp_m_idx = width - 1;
                vp_idx = 0;
                vm_idx = width - 1;

                initial_p[0] = src[0];
                initial_m[0] = src[width - 1];

                for (col = 0; col < width; col++) {
                    terms = (col < 4) ? col : 4;

                    for (i = 0; i <= terms; i++) {
                        val_p[vp_idx] += n_p[i] * src[sp_p_idx - i]
                                - d_p[i] * val_p[vp_idx - i];
                        val_m[vm_idx] += n_m[i] * src[sp_m_idx + i]
                                - d_m[i] * val_m[vm_idx + i];
                    }
                    for (j = i; j <= 4; j++) {
                        val_p[vp_idx] += (n_p[j] - bd_p[j]) * initial_p[0];
                        val_m[vm_idx] += (n_m[j] - bd_m[j]) * initial_m[0];
                    }

                    sp_p_idx++;
                    sp_m_idx--;
                    vp_idx++;
                    vm_idx--;
                }

                transferGaussPixels(val_p, val_m, dst, 1, width);

                for (t = 0; t < width; t++) {
                    psrc[row * row_stride + t] = dst[t];
                }
            }
        }

        return 0;
    }
    private static void findConstants(double[] n_p, double[] n_m,
            double[] d_p, double[] d_m, double[] bd_p, double[] bd_m,
            double std_dev) {
        double div = Math.sqrt(2 * 3.141593) * std_dev;
        double x0 = -1.783 / std_dev;
        double x1 = -1.723 / std_dev;
        double x2 = 0.6318 / std_dev;
        double x3 = 1.997 / std_dev;
        double x4 = 1.6803 / div;
        double x5 = 3.735 / div;
        double x6 = -0.6803 / div;
        double x7 = -0.2598 / div;
        int i;

        n_p[0] = x4 + x6;
        n_p[1] = (Math.exp(x1)
                * (x7 * Math.sin(x3) - (x6 + 2 * x4) * Math.cos(x3)) + Math
                .exp(x0)
                * (x5 * Math.sin(x2) - (2 * x6 + x4) * Math.cos(x2)));
        n_p[2] = (2
                * Math.exp(x0 + x1)
                * ((x4 + x6) * Math.cos(x3) * Math.cos(x2) - x5
                        * Math.cos(x3) * Math.sin(x2) - x7 * Math.cos(x2)
                        * Math.sin(x3)) + x6 * Math.exp(2 * x0) + x4
                * Math.exp(2 * x1));
        n_p[3] = (Math.exp(x1 + 2 * x0)
                * (x7 * Math.sin(x3) - x6 * Math.cos(x3)) + Math.exp(x0 + 2
                * x1)
                * (x5 * Math.sin(x2) - x4 * Math.cos(x2)));
        n_p[4] = 0.0;

        d_p[0] = 0.0;
        d_p[1] = -2 * Math.exp(x1) * Math.cos(x3) - 2 * Math.exp(x0)
                * Math.cos(x2);
        d_p[2] = 4 * Math.cos(x3) * Math.cos(x2) * Math.exp(x0 + x1)
                + Math.exp(2 * x1) + Math.exp(2 * x0);
        d_p[3] = -2 * Math.cos(x2) * Math.exp(x0 + 2 * x1) - 2
                * Math.cos(x3) * Math.exp(x1 + 2 * x0);
        d_p[4] = Math.exp(2 * x0 + 2 * x1);

        for (i = 0; i <= 4; i++) {
            d_m[i] = d_p[i];
        }

        n_m[0] = 0.0;
        for (i = 1; i <= 4; i++) {
            n_m[i] = n_p[i] - d_p[i] * n_p[0];
        }

        double sum_n_p, sum_n_m, sum_d;
        double a, b;

        sum_n_p = 0.0;
        sum_n_m = 0.0;
        sum_d = 0.0;

        for (i = 0; i <= 4; i++) {
            sum_n_p += n_p[i];
            sum_n_m += n_m[i];
            sum_d += d_p[i];
        }

        a = sum_n_p / (1.0 + sum_d);
        b = sum_n_m / (1.0 + sum_d);

        for (i = 0; i <= 4; i++) {
            bd_p[i] = d_p[i] * a;
            bd_m[i] = d_m[i] * b;
        }
    }
    private static void transferGaussPixels(double[] src1, double[] src2,
            int[] dest, int bytes, int width) {
        int i, j, k, b;
        int bend = bytes * width;
        double sum;

        i = j = k = 0;
        for (b = 0; b < bend; b++) {
            sum = src1[i++] + src2[j++];

            if (sum > 255)
                sum = 255;
            else if (sum < 0)
                sum = 0;

            dest[k++] = (int) sum;
        }
    }
}

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