Added debug methods

Fixed System namespace usage

src/ImageSharp/Formats/Jpeg/Components/Encoder/HuffmanScanEncoder.cs

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0.
 
 using System.IO;
+using System.Linq;
 using System.Runtime.CompilerServices;
 using System.Threading;
 using SixLabors.ImageSharp.Memory;
@@ -427,5 +428,53 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Components.Encoder
             return Numerics.Log2(value << 1);
 #endif
         }
+
+        // !!! DO NOT DELETE THIS !!! until custom huffman tables are supported - this is very handy for debugging
+        /// <summary>
+        /// Prints given huffman codes to the System.Console for debugging puroses.
+        /// </summary>
+        /// <param name="codes">Codes array.</param>
+        /// <param name="title">Custom title to print.</param>
+        /// <param name="printCode">Flag indicating if all codes should be printed.</param>
+        /// <param name="codePrintBase">Indicates which number base will be used to print codes</param>
+        private static void PrintHuffmanSummary(int[] codes, string title, bool printCode, int codePrintBase = 2)
+        {
+            System.Console.WriteLine(title);
+            System.Console.WriteLine($"Codes count: {codes.Length}");
+
+            // This is possible if custom tree is provided, especially for per-image optimized tree
+            if (codes.Length == 0)
+            {
+                return;
+            }
+
+            // Min
+            int min = codes.Min();
+            int min_len = min >> 24;
+            string min_code = System.Convert.ToString(min & ((1 << 24) - 1), codePrintBase);
+
+            // Max
+            int max = codes.Max();
+            int max_len = max >> 24;
+            string max_code = System.Convert.ToString(max & ((1 << 24) - 1), codePrintBase);
+
+            System.Console.WriteLine($"Min code: {min_code}, len: {min_len} \nMax code: {max_code}, len: {max_len}");
+
+            // Printing codes
+            if (printCode)
+            {
+                PrintHuffmanCodes(codes, codePrintBase);
+            }
+        }
+
+        private static void PrintHuffmanCodes(int[] codes, int codePrintBase)
+        {
+            for (int i = 0; i < codes.Length; i++)
+            {
+                int huffCode = codes[i];
+                string code = System.Convert.ToString(huffCode & ((1 << 24) - 1), codePrintBase);
+                System.Console.WriteLine($"\t{code}");
+            }
+        }
     }
 }