1. 程式人生 > >濾波 降噪 灰度 二值化 去除文字邊框 去除驗證碼干擾線

濾波 降噪 灰度 二值化 去除文字邊框 去除驗證碼干擾線

import org.apache.xmlgraphics.image.codec.tiff.TIFFEncodeParam;
import org.apache.xmlgraphics.image.codec.util.ImageEncoder;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import
java.io.OutputStream; import java.util.ArrayList; import java.util.List; public class ImageUtil { public static void main(String[] args) throws IOException { File testDataDir = new File("pic"); final String destDir = "picimages"; for (File file : testDataDir.listFiles()) { cleanLinesInImage(file, destDir); cleanLinesInImage(file, destDir); cleanLinesInImage(file, destDir); } } /** * @param
sfile 需要去噪的影象 * @param destDir 去噪後的影象儲存地址 * @throws IOException */
public static void cleanLinesInImage(File sfile, String destDir) throws IOException { File destF = new File(destDir); if (!destF.exists()) { destF.mkdirs(); } BufferedImage bufferedImage = ImageIO.read(sfile); int
h = bufferedImage.getHeight(); int w = bufferedImage.getWidth(); // 灰度化 int[][] gray = new int[w][h]; for (int x = 0; x < w; x++) { for (int y = 0; y < h; y++) { int argb = bufferedImage.getRGB(x, y); // 影象加亮(調整亮度識別率非常高) int r = (int) (((argb >> 16) & 0xFF) * 1.1 + 30); int g = (int) (((argb >> 8) & 0xFF) * 1.1 + 30); int b = (int) (((argb >> 0) & 0xFF) * 1.1 + 30); if (r >= 255) { r = 255; } if (g >= 255) { g = 255; } if (b >= 255) { b = 255; } gray[x][y] = (int) Math .pow((Math.pow(r, 2.2) * 0.2973 + Math.pow(g, 2.2) * 0.6274 + Math.pow(b, 2.2) * 0.0753), 1 / 2.2); } } // 二值化 int threshold = ostu(gray, w, h); BufferedImage binaryBufferedImage = new BufferedImage(w, h, BufferedImage.TYPE_BYTE_BINARY); for (int x = 0; x < w; x++) { for (int y = 0; y < h; y++) { if (gray[x][y] > threshold) { gray[x][y] |= 0x00FFFF; } else { gray[x][y] &= 0xFF0000; } binaryBufferedImage.setRGB(x, y, gray[x][y]); } } //去除干擾線條 // for(int y = 1; y < h-1; y++){ // for(int x = 1; x < w-1; x++){ // boolean flag = false ; // if(isBlack(binaryBufferedImage.getRGB(x, y))){ // //左右均為空時,去掉此點 // if((binaryBufferedImage.getRGB(x-1, y)) && isWhite(binaryBufferedImage.getRGB(x+1, y))){ // flag = true; // } // //上下均為空時,去掉此點 // if(isWhite(binaryBufferedImage.getRGB(x, y+1)) && isWhite(binaryBufferedImage.getRGB(x, y-1))){ // flag = true; // } // //斜上下為空時,去掉此點 // if(isWhite(binaryBufferedImage.getRGB(x-1, y+1)) && isWhite(binaryBufferedImage.getRGB(x+1, y-1))){ // flag = true; // } // if(isWhite(binaryBufferedImage.getRGB(x+1, y+1)) && isWhite(binaryBufferedImage.getRGB(x-1, y-1))){ // flag = true; // } // if(flag){ // binaryBufferedImage.setRGB(x,y,-1); // } // } // } // } //去除邊框線 for (int y = 1; y < h; y++) { for (int x = 1; x < w; x++) { boolean flag = true; int px = 15; if (isBlack(binaryBufferedImage.getRGB(x, y))) { if (x < w - px) { for (int i = 1; i <= px; i++) { //右15畫素均為空時,去掉此行 if (isWhite(binaryBufferedImage.getRGB(x + i, y))) { flag = false; if (!flag) { break; } } } } for (int i = x; i < w; i++) { if (flag) { if (isBlack(binaryBufferedImage.getRGB(i, y))) { binaryBufferedImage.setRGB(i, y, -1); } else { break; } } } flag = true; if (y < h - px) { for (int i = 1; i <= px; i++) { //下15畫素均為空時,去掉此列 if (isWhite(binaryBufferedImage.getRGB(x, y + i))) { flag = false; if (!flag) { break; } } } } for (int i = y; i <= h; i++) { if (flag) { if (isBlack(binaryBufferedImage.getRGB(x, i))) { binaryBufferedImage.setRGB(x, i, -1); } else { break; } } } } } } // 矩陣列印 for (int y = 0; y < h; y++) { for (int x = 0; x < w; x++) { if (isBlack(binaryBufferedImage.getRGB(x, y))) { System.out.print("*"); } else { System.out.print(" "); } } System.out.println(); } ImageIO.write(binaryBufferedImage, "tif", new File(destDir, sfile .getName())); } public static boolean isBlack(int colorInt) { Color color = new Color(colorInt); if (color.getRed() + color.getGreen() + color.getBlue() <= 300) { return true; } return false; } public static boolean isWhite(int colorInt) { Color color = new Color(colorInt); if (color.getRed() + color.getGreen() + color.getBlue() > 300) { return true; } return false; } public static int isBlackOrWhite(int colorInt) { if (getColorBright(colorInt) < 30 || getColorBright(colorInt) > 730) { return 1; } return 0; } public static int getColorBright(int colorInt) { Color color = new Color(colorInt); return color.getRed() + color.getGreen() + color.getBlue(); } public static int ostu(int[][] gray, int w, int h) { int[] histData = new int[w * h]; // Calculate histogram for (int x = 0; x < w; x++) { for (int y = 0; y < h; y++) { int red = 0xFF & gray[x][y]; histData[red]++; } } // Total number of pixels int total = w * h; float sum = 0; for (int t = 0; t < 256; t++) { sum += t * histData[t]; } float sumB = 0; int wB = 0; int wF = 0; float varMax = 0; int threshold = 0; for (int t = 0; t < 256; t++) { wB += histData[t]; // Weight Background if (wB == 0) { continue; } wF = total - wB; // Weight Foreground if (wF == 0) { break; } sumB += (float) (t * histData[t]); float mB = sumB / wB; // Mean Background float mF = (sum - sumB) / wF; // Mean Foreground // Calculate Between Class Variance float varBetween = (float) wB * (float) wF * (mB - mF) * (mB - mF); // Check if new maximum found if (varBetween > varMax) { varMax = varBetween; threshold = t; } } return threshold; } }

原圖

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處理後圖片

這裡寫圖片描述