画像から任意の向きの線を取り除く方法

Question

基本的には、キャプチャのテキスト画像に一般的に見られるようなテキストをオーバーレイする可能性がある線を削除したいので、後の画像にはテキストのみが含まれています。どのようにこの問題を解決するための任意の提案をいただければ幸いです。

Answer 1

既存のキャプチャイメージジェネレータを編集しますか（特定のキャプチャの実装に関連している可能性があり、ここで実装コードを公開しないため難しいでしょう）、または新しいキャプチャを生成しますかオーバーレイテキストなしで滑らかできれいに見えます）？

ここでは、自分のJSP Webアプリケーションページのために自分のキャプチャを作成したときのことです。 JSPインポート文を削除し、JAVAインポート文で置き換える必要があります。必要に応じて、コードを自由に編集し、独自のキャプチャを生成することができます（グラフィックを編集する）。お役に立てれば ！

<%@ page import="java.util.*"%> 
<%@ page import="java.io.*"%> 
<%@ page import="javax.servlet.*"%> 
<%@ page import="javax.servlet.http.*"%> 
<%@ page import="java.awt.*"%> 
<%@ page import="java.awt.image.*"%> 
<%@ page import="javax.imageio.*"%> 
<%@ page import="java.awt.geom.*"%> 
<% 
    response.setContentType("image/jpg"); 

    try { 

     Color backgroundColor = Color.green; 
     Color borderColor = Color.orange; 
     Color textColor = Color.white; 
     Color circleColor = Color.green; 
     Font textFont = new Font("Arial", Font.PLAIN, 24); 
     int charsToPrint = 6; 
     int width = request.getParameter("width") != null ? Integer.parseInt(request.getParameter("width")) : 150; 
     int height = request.getParameter("height") != null ? Integer.parseInt(request.getParameter("height")) : 80; 
     int circlesToDraw = 6; 
     float horizMargin = 20.0f; 
     float imageQuality = 0.95f; // max is 1.0 (this is for jpeg) 
     double rotationRange = 0.7; // this is radians 
     BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); 

     Graphics2D g = (Graphics2D) bufferedImage.getGraphics(); 

     //Draw an oval 
     g.setColor(Color.DARK_GRAY); 
     g.fillRect(0, 0, width, height); 

     // lets make some noisey circles 
     g.setColor(circleColor); 
     for (int i = 0; i < circlesToDraw; i++) { 
      int circleRadius = (int) (Math.random() * height/2.0); 
      int circleX = (int) (Math.random() * width - circleRadius); 
      int circleY = (int) (Math.random() * height - circleRadius); 
      g.drawOval(circleX, circleY, circleRadius * 2, circleRadius * 2); 
     } 

     g.setColor(textColor); 
     g.setFont(textFont); 

     FontMetrics fontMetrics = g.getFontMetrics(); 
     int maxAdvance = fontMetrics.getMaxAdvance(); 
     int fontHeight = fontMetrics.getHeight(); 

     // i removed 1 and l and i because there are confusing to users... 
     // Z, z, and N also get confusing when rotated 
     // 0, O, and o are also confusing... 
     // lowercase G looks a lot like a 9 so i killed it 
     // this should ideally be done for every language... 
     // i like controlling the characters though because it helps prevent confusion 
     String elegibleChars = "ABCDEFGHJKLMPQRSTUVWXYabcdefhjkmnpqrstuvwxy23456789"; 
     char[] chars = elegibleChars.toCharArray(); 

     float spaceForLetters = -horizMargin * 2 + width; 
     float spacePerChar = spaceForLetters/(charsToPrint - 1.0f); 

     AffineTransform transform = g.getTransform(); 

     StringBuffer finalString = new StringBuffer(); 

     for (int i = 0; i < charsToPrint; i++) { 
      double randomValue = Math.random(); 
      int randomIndex = (int) Math.round(randomValue * (chars.length - 1)); 
      char characterToShow = chars[randomIndex]; 
      finalString.append(characterToShow); 

      // this is a separate canvas used for the character so that 
      // we can rotate it independently 
      int charImageWidth = maxAdvance * 2; 
      int charImageHeight = fontHeight * 2; 
      int charWidth = fontMetrics.charWidth(characterToShow); 
      int charDim = Math.max(maxAdvance, fontHeight); 
      int halfCharDim = (int) (charDim/2); 

      BufferedImage charImage = new BufferedImage(charDim, charDim, BufferedImage.TYPE_INT_ARGB); 
      Graphics2D charGraphics = charImage.createGraphics(); 
      charGraphics.translate(halfCharDim, halfCharDim); 
      double angle = (Math.random() - 0.5) * rotationRange; 
      charGraphics.transform(AffineTransform.getRotateInstance(angle)); 
      charGraphics.translate(-halfCharDim,-halfCharDim); 
      charGraphics.setColor(textColor); 
      charGraphics.setFont(textFont); 

      int charX = (int) (0.5 * charDim - 0.5 * charWidth); 
      charGraphics.drawString("" + characterToShow, charX,(int) ((charDim - fontMetrics.getAscent())/2 + fontMetrics.getAscent())); 

      float x = horizMargin + spacePerChar * (i) - charDim/2.0f; 
      int y = (int) ((height - charDim)/2); 

      g.drawImage(charImage, (int) x, y, charDim, charDim, null, null); 

      charGraphics.dispose(); 
     } 

     //Write the image as a jpg 
     Iterator iter = ImageIO.getImageWritersByFormatName("JPG"); 
     if(iter.hasNext()) { 
      ImageWriter writer = (ImageWriter)iter.next(); 
      ImageWriteParam iwp = writer.getDefaultWriteParam(); 
      iwp.setCompressionMode(ImageWriteParam.MODE_EXPLICIT); 
      iwp.setCompressionQuality(imageQuality); 
      writer.setOutput(ImageIO.createImageOutputStream(response.getOutputStream())); 
      IIOImage imageIO = new IIOImage(bufferedImage, null, null); 
      writer.write(null, imageIO, iwp); 
     } else { 
      throw new RuntimeException("no encoder found for jsp"); 
     } 

     // let's stick the final string in the session (optional, only if you use JSP session object, and want to save it inside the user session) 
     session.setAttribute("captcha", finalString.toString()); 

     g.dispose(); 
    } 
    catch (IOException ioe) { 
      throw new RuntimeException("Unable to build image" , ioe); 
    } 
%>