ID 353546 - Denoise node: Digital source type does not work for all input resolutions

Problem summary
The Digital source type of the Denoise node does not trigger any image processing for large input image resolutions, for example 4k. This works as expected for 2k resolutions, and similarly, using the Film type works as expected for all resolutions.  

Customer reported version
nuke.11.1v3

Customer reported platform
centos7

Steps to reproduce
1) open Nuke and read in a 4k image
2) connect a Denoise node after the Read node and make sure the Source knob is set to 'Digital'
3) move the analysis region somewhere inside the image
4) zoom in close to the selected region and you will notice the noise has not been removed
5) change the Source knob to 'Film' and move the analysis region slightly to trigger the re-analysis. 

Result: the noise is now removed and below is a before and after comparison example:

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Workaround
Using 'Film' type instead of 'Digital' will enable the denoise processing for any resolution images. 

Reproduced by support
This bug has been reproduced in:
Nuke11.1v4 - Windows 7, CentOS 6, Mac OS X 10.11
Nuke11.1v1 - Windows 7
Nuke11.0v1 - Windows 7
Nuke10.5v7 - Windows 7 
Nuke10.0v1 - Windows 7 
Nuke9.0v9 - Windows 7 
Nuke8.0v7 - Windows 7 
Nuke7.0v10 - Windows 7, CentOS 6, Mac OS X 10.11

Earliest version tested
Nuke 7.0v10 - This issue appears to be in all versions of the product

Expected behaviour
Using Digital as source type for the Denoise node should enable the denoising processing on any image resolution. 

Actual behaviour
Currently only Film type triggers the denoise processing on any image resolution and Digital type appears to not work on all image resolutions, like 4k.