Question

android图像处理 为什么我这段代码图像显示不出来？我输入的是只有黑白两色的图像

想用sobel算子画出边缘来，哪里出错了吗？图像显示不出来啊dst存储的是输入图像bitmap1的像素值，dst2存放的是我进行运算之后的像素值





Answer 1

调用例子
resultBitmap = (Bitmap) intent.getParcelableExtra("resultBitmap");
// 图片与处理
BitmapFilter bitmapFilter = new BitmapFilter(resultBitmap);
bitmapFilter.changeGrey();
resultBitmap = bitmapFilter.getBitmap();

以下是BitmapFilter
package com.example.androcr;

import android.graphics.Bitmap;
import android.graphics.Color;

/**
* 图像预处理类
* @author Administrator
*/
public class BitmapFilter {

private Bitmap bitmap;
private int iw;
private int ih;
private int[] pixels;

public BitmapFilter(Bitmap bitmap) {
this.bitmap = bitmap;
this.iw = bitmap.getWidth();
this.ih = bitmap.getHeight();
pixels = new int[iw * ih];
// 将bitmap转化为pixel数组
bitmap.getPixels(pixels, 0, iw, 0, 0, iw, ih);
}

public Bitmap getBitmap() {
// 将pixel数组转化为bitmap
bitmap = Bitmap.createBitmap(pixels, iw, ih, Bitmap.Config.ARGB_8888);
return bitmap;
}

/**
* 图像的二值化
*/
public void changeGrey() {
// 选取的阈值
int grey = 120;
int pixel;
int alpha, red, green, blue;
for (int i = 0; i < iw * ih; i++) {
pixel = pixels[i];
alpha = Color.alpha(pixel);
red = Color.red(pixel);
green = Color.green(pixel);
blue = Color.blue(pixel);
red = (red > grey) ? 255 : 0;
green = (green > grey) ? 255 : 0;
blue = (blue > grey) ? 255 : 0;
pixels[i] = alpha << 24 | red << 16 | green << 8 | blue;
}
}

/**
* 图像的锐化
*/
public void sharp() {
// 像素中间变量
int tempPixels[] = new int[iw * ih];
for (int i = 0; i < iw * ih; i++) {
tempPixels[i] = pixels[i];
}
int alpha;
int red6, red5, red8, sharpRed;
int green5, green6, green8, sharpGreen;
int blue5, blue6, blue8, sharpBlue;
for (int i = 1; i < ih - 1; i++) {
for (int j = 1; j < iw - 1; j++) {
alpha = Color.alpha(pixels[i * iw + j]);
// 对图像进行尖锐化
// 锐化red
red6 = Color.red(pixels[i * iw + j + 1]);
red5 = Color.red(pixels[i * iw + j]);
red8 = Color.red(pixels[(i + 1) * iw + j]);
sharpRed = Math.abs(red6 - red5) + Math.abs(red8 - red5);
// 锐化green
green5 = Color.green(pixels[i * iw + j]);
green6 = Color.green(pixels[i * iw + j + 1]);
green8 = Color.green(pixels[(i + 1) * iw + j]);
sharpGreen = Math.abs(green6 - green5)
+ Math.abs(green8 - green5);
// 锐化blue
blue5 = Color.blue(pixels[i * iw + j]);
blue6 = Color.blue(pixels[i * iw + j + 1]);
blue8 = Color.blue(pixels[(i + 1) * iw + j]);
sharpBlue = Math.abs(blue6 - blue5)
+ Math.abs(blue8 - blue5);
// 处理颜色溢出
if (sharpRed > 255)
sharpRed = 255;
if (sharpGreen > 255)
sharpGreen = 255;
if (sharpBlue > 255)
sharpBlue = 255;
tempPixels[i * iw + j] = alpha << 24 | sharpRed << 16
| sharpGreen << 8 | sharpBlue;
}
}
pixels = tempPixels;
}

/**
* 中值滤波
*/
public void median() {
// 对图像进行中值滤波
int alpha, red, green, blue;
int red4, red5, red6;
int green4, green5, green6;
int blue4, blue5, blue6;
for (int i = 1; i < ih - 1; i++) {
for (int j = 1; j < iw - 1; j++) {
// alpha值保持不变
alpha = Color.alpha(pixels[i * iw + j]);
// 处理red分量
red4 = Color.red(pixels[i * iw + j - 1]);
red5 = Color.red(pixels[i * iw + j]);
red6 = Color.red(pixels[i * iw + j + 1]);
// 水平方向进行中值滤波
if (red4 >= red5) {
if (red5 >= red6) {
red = red5;
} else {
if (red4 >= red6) {
red = red6;
} else {
red = red4;
}
}
} else {
if (red4 > red6) {
red = red4;
} else {
if (red5 > red6) {
red = red6;
} else {
red = red5;
}
}
}
// 处理green分量
green4 = Color.green(pixels[i * iw + j - 1]);
green5 = Color.green(pixels[i * iw + j]);
green6 = Color.green(pixels[i * iw + j + 1]);
// 水平方向进行中值滤波
if (green4 >= green5) {
if (green5 >= green6) {
green = green5;
} else {
if (green4 >= green6) {
green = green6;
} else {
green = green4;
}
}
} else {
if (green4 > green6) {
green = green4;
} else {
if (green5 > green6) {
green = green6;
} else {
green = green5;
}
}
}
// 处理blue分量
blue4 = Color.blue(pixels[i * iw + j - 1]);
blue5 = Color.blue(pixels[i * iw + j]);
blue6 = Color.blue(pixels[i * iw + j + 1]);
// 水平方向进行中值滤波
if (blue4 >= blue5) {
if (blue5 >= blue6) {
blue = blue5;
} else {
if (blue4 >= blue6) {
blue = blue6;
} else {
blue = blue4;
}
}
} else {
if (blue4 > blue6) {
blue = blue4;
} else {
if (blue5 > blue6) {
blue = blue6;
} else {
blue = blue5;
}
}
}
pixels[i * iw + j] = alpha << 24 | red << 16 | green << 8
| blue;
}
}
}

/**
* 图像的平滑
*/
public void smooth() {
int[] tempPixels = new int[iw * ih];
//图像的平滑
int min = -1000;
int max = 1000;
for (int i = 0; i < ih; i++) {
for (int j = 0; j < iw; j++) {
if (i == 0 || i == 1 || i == ih - 1 || i == ih - 2 || j == 0
|| j == 1 || j == iw - 1 || j == iw - 2) {
tempPixels[i * iw + j] = pixels[i * iw + j];
} else {
// 中心的九个像素点
float average = (
pixels[i * iw + j]
+ pixels[i * iw + j - 1]
+ pixels[i * iw + j + 1]
+ pixels[(i - 1) * iw + j]
+ pixels[(i - 1) * iw + j - 1]
+ pixels[(i - 1) * iw + j + 1]
+ pixels[(i + 1)]
+ pixels[(i + 1) * iw + j]
+ pixels[(i + 1) * iw + j - 1]
) / 9;
tempPixels[i * iw + j] = (int) (average);
}
if (tempPixels[i * iw + j] < min)
min = tempPixels[i * iw + j];
if (tempPixels[i * iw + j] > max)
max = tempPixels[i * iw + j];
}
}
for (int i = 0; i < iw * ih; i++) {
tempPixels[i] = (tempPixels[i] - min) * 255 / (max - min);
}
pixels = tempPixels;
}

}