NOTE: Some strings (and integers for containing sizes) have been provided as class variables and have been left out.

public string Compress(string stringToCompress)
{
string result = string.Empty;
char previousLetter = ”;

for (int i = 0; i l == currentLetter);
if (currentLetter != previousLetter)
{
if ((int)count > 1)
result += CONTROL_CHARACTER + count.ToString() + currentLetter;
else result += currentLetter;
}
previousLetter = currentLetter;
}
CompressedSizeInBytes = result.Length;
return result;
}

And a simple decompression:

public string DeCompress(string stringToDeCompress)
{
string result = string.Empty;

string pattern = @”(\d+)([A-Za-z])”;

Regex r = new Regex(pattern);
Match m = r.Match(stringToDeCompress);

int oldIndex = 0;
while ( m.Success )
{
int newIndex = m.Index;
result += stringToDeCompress.Substring(oldIndex, (newIndex – oldIndex)-1);
oldIndex = newIndex + m.Length;

for (int i = 0; i < Int32.Parse(m.Groups[1].Value ); i++)
result += m.Groups[2].Value;
m = m.NextMatch();
}
//Capture the last known chars (will only occur if there are characters at the end with only 1 occurence…
if (oldIndex < stringToDeCompress.Length)
result += stringToDeCompress.Substring(oldIndex, stringToDeCompress.Length – oldIndex);
return result;

}

I hope this will help others. Note that it's not written for effiency, only for testing purposes. I haven't tested this code on images.

Regards,

Robert.