For the given image I have launched "Batch Processing" and then added "Canvas resize" with parameter width=400. As a result black color was used for filling. Expected that white color is used. When I do the same action via the menu, everything is fine.
Source image (TIFF monochrome): source.tiff result.tiff
XnView Version: 1.99
"Canvas resize" in batch mode results black border
Moderators: helmut, XnTriq, xnview