Added verification trough the isValid method of the chunck

TEST_DecodePng/Form1.cs

@@ -80,7 +80,7 @@ namespace TEST_DecodePng
         private void btnDecode_Click(object sender, EventArgs e)
         {
             PngDecoder decoder = new PngDecoder();
-            /*
+            
             try{
                 decoder.Decode(selectedFile);
             }
@@ -88,10 +88,7 @@ namespace TEST_DecodePng
             {
                 MessageBox.Show(ex.Message);
             }
-            */
-
-            decoder.Decode(selectedFile);
-
+            //decoder.Decode(selectedFile);
         }
     }
 }

TEST_DecodePng/PngDecoder.cs

@@ -162,6 +162,10 @@ namespace TEST_DecodePng
                         chunckCursor++;
 
                         header = new PngMetaData(imageHeight, imageWidth, (sbyte)bitDepth, (sbyte)colorType, (sbyte)compressionMethod, (sbyte)filterMethod, (sbyte)interlaceMethod);
+
+                        if (!header.IsValid())
+                            throw new InvalidPngHeadersFileException("Header invalide");
+
                         break;
                     default:
                         break;