Sending of large messages is slow

[Nikzt]

Problem is that the Java implementation in Matlab cannot accept raw buffers and each byte has to be sent out separately.
Recent Matlab versions have the tcpclient function, use that instead - those can send large buffers at once.

It would be nice if this could be implemented in a backward-compatible way so that people who have older Matlab can use the library, too.

[lassoan]

You need to change this file:
https://github.com/SlicerIGT/MatlabOpenIGTLink/blob/master/src/OpenIGTLinkMessageReceiver.m

1. Replace ReadWithTimeout with tcpread
   Do it in a backward-compatible manner: use a function handle to the old or new ReadWithTimeout implementation.
2. Replace this block with some memory/type casting to avoid iterating through the pixels one by one:
   data.pixelData = zeros(volumeSizeI, volumeSizeJ, volumeSizeK);
   for kIndex=1:volumeSizeK
   for jIndex=1:volumeSizeJ
   for iIndex=1:volumeSizeI
   data.pixelData(i,j,k) = convertFromUint8VectorToFloat64(body(i:i+8)); i = i + 8;
   end
   end
   end
3. Get rid of global variables along the way.