Delphi: How to decode Base64 encoded string into viewable bitmap image

Hi,

I'm referring to previous question titled Decode hex text file into viewable bitmap image, which targeted VB.NET development.
http://www.experts-exchange.com/Programming/Languages/.NET/Visual_Basic.NET/Q_22710540.html

Does anybody know how to perform similar task in Delphi?

I also have a string encoded in Base64 , which is the result of capturing a signature image from a PDA. The string looks like below:

PRY7FTcUNBQyFjEYMhozHDYcNx84ITYjMyQxJS8kLSQtJP//QxJCFEIWQhlBG0EdQR9BIUMfQx///1YOVhBUD1IQUBBNEUwTSxZMGE0aTxxRHFMeVR9XHlgbWBlWGFMYURhPGE8Y//9gGl8YXxZfFF8SYBBgDmIPYxFkFGUXZhloFmgUaRFqDmoMagpqCv//Rz1HP0dBR0RGRkZJRktGTUZN//9NPE4+TkBOQ09FT0dQSlFMUEpPR09FTURLRUlFR0RHRP//WzxZO1Y9VD1SP1JBUkNTRVVHWEhaSFpI//9aQVhBVkFTQVFAUUD//2NEY0FiP2I8YjpiOGQ2ZjVoN2o5aztqPWk/Z0BkQGI+Y0BlQWdCakNsQ25EbkT//3w0eTR3NXQ2cjdwOW87cD1yP3RAdkJ4QnpDekP//3k5dzp1OnM6cTpuOW45//8=

here is what the PDA vendor says about the file:
-----------------------------------------------------------------
Ok, the data coming in is basically a list of lines to draw.

To make the data in the first place, a series of points that would create the lines of the signature are recorded, where any pen lift (i.e. the drawing stopped) is recorded as 255,255 to serve as a terminator.

This array of points is turned into a byte array (i.e. line from 2,3 to 40, 50 to 80, 3 becomes byte[] {2,3,40,50, 80, 3} )

This is run through a Microsoft call Convert.ToBase64String to cut down on size (ever seen how big an xml encoded byte array is?) and make it easier to pass the data back into a webservice via a string parameter.  The data will need to be de-converted from this form to get the byte array back out, that is then used to draw the lines in the code sample you supplied.
-----------------------------------------------------------------

How to convert this string back into a viewable Bitmap image using DELPHI? How about in PHP?

I believe that from the byte array, each pair is a point. So to draw the signature you just draw the points. So byte[0] =  31 and byte[1] = 102 is point 1. Then you would draw a line from this point to the next point which is byte[2] and byte[3] and then you would draw a line from this to the next point and so on.

They also sent us a function (in C#) to draw the byte array but how to convert this function into Delphi and PHP?

thanks
AnthonyStart Free Trial

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using System;
using System.Drawing;
using System.Collections;
 
namespace ADS.WorkstationPC
{
	/// <summary>
	/// Summary description for SignatureToBitmap.
	/// </summary>
	public class SignatureToBitmap
	{
		private static SignatureToBitmap UniqueBitmap = new SignatureToBitmap();
		private SignatureToBitmap()
		{
			//
			// TODO: Add constructor logic here
			//
 
		}
		public static Bitmap GetBitmap(byte[] rawsignature)
		{
			Bitmap bmSignature = new Bitmap(254, 254);
			Graphics gr = Graphics.FromImage(bmSignature);
			Pen pen = new Pen(new SolidBrush(Color.Black), 1);
			ArrayList alline = new ArrayList();
			ArrayList alpoint = new ArrayList();
 
			foreach (byte abyte in rawsignature)
			{
				alpoint.Add((int)abyte);
				if (alpoint.Count > 1)
				{
					Point apoint = new Point((int)alpoint[0], (int)alpoint[1]);
					alpoint.Clear(); // clear the array list
					alline.Add(apoint); //adds to the end of the array list
					if (apoint.X == 255) 
						alline.Clear();
                    else if (alline.Count > 1)
					{
						Point firstpoint = (Point)alline[0]; //?
						alline.RemoveAt(0); // removes the element at that index
						gr.DrawLine(pen, firstpoint, apoint);
					}
				}
			}
 
			return bmSignature;
		}
	}
}