Merge pull request #96 from rr83019/image-dpi

Set Image DPI for captcha providers

src/main/scala/lc/captchas/DebugCaptcha.scala

@@ -1,6 +1,5 @@
 package lc.captchas
 
-import javax.imageio.ImageIO
 import java.awt.Color
 import java.awt.Font
 import java.awt.font.TextLayout
@@ -12,6 +11,7 @@ import java.util.List
 import lc.misc.HelperFunctions
 import lc.captchas.interfaces.Challenge
 import lc.captchas.interfaces.ChallengeProvider
+import lc.misc.PngImageWriter
 
 /** This captcha is only for debugging purposes. It creates very simple captchas that are deliberately easy to solve with OCR engines */
 class DebugCaptcha extends ChallengeProvider {
@@ -53,7 +53,7 @@ class DebugCaptcha extends ChallengeProvider {
     graphics2D.dispose()
     val baos = new ByteArrayOutputStream()
     try {
-      ImageIO.write(img, "png", baos)
+      PngImageWriter.write(baos, img);
     } catch {
       case e: Exception =>
         e.printStackTrace()

src/main/scala/lc/captchas/FilterChallenge.scala

@@ -8,6 +8,8 @@ import java.awt.Color
 import lc.captchas.interfaces.ChallengeProvider
 import lc.captchas.interfaces.Challenge
 import java.util.{List => JavaList, Map => JavaMap}
+import java.io.ByteArrayOutputStream
+import lc.misc.PngImageWriter
 
 class FilterChallenge extends ChallengeProvider {
   def getId = "FilterChallenge"
@@ -41,7 +43,15 @@ class FilterChallenge extends ChallengeProvider {
     var image = ImmutableImage.fromAwt(canvas)
     val s = scala.util.Random.nextInt(2)
     image = filterTypes(s).applyFilter(image)
-    new Challenge(image.bytes(new nio.PngWriter()), "image/png", secret)
+    val img = image.awt()
+    val baos = new ByteArrayOutputStream()
+    try {
+      PngImageWriter.write(baos, img);
+    } catch {
+      case e: Exception =>
+        e.printStackTrace()
+    }
+    new Challenge(baos.toByteArray, "image/png", secret)
   }
   def checkAnswer(secret: String, answer: String): Boolean = {
     secret == answer

src/main/scala/lc/captchas/LabelCaptcha.scala

@@ -10,6 +10,7 @@ import java.awt.Color
 import lc.captchas.interfaces.ChallengeProvider
 import lc.captchas.interfaces.Challenge
 import java.util.{List => JavaList, Map => JavaMap}
+import lc.misc.PngImageWriter
 
 class LabelCaptcha extends ChallengeProvider {
   private var knownFiles = new File("known").list.toList
@@ -49,7 +50,7 @@ class LabelCaptcha extends ChallengeProvider {
 
       val token = encrypt(knownImageFile + "," + unknownImageFile)
       val baos = new ByteArrayOutputStream()
-      ImageIO.write(mergedImage, "png", baos)
+      PngImageWriter.write(baos, mergedImage);
 
       new Challenge(baos.toByteArray(), "image/png", token)
     }