Help Needed - Trying to extract/isolate a photo reflection visible on a glass window

[Matt @ Abingdon Capital]

To anyone out there who might have a solution to my problem - I'm trying to extract/isolate a reflection shown in a photo; the photo was taken from the inside of a building, capturing the outside scenery through a glass window.  I'm working on an art project and I want to extract/isolate the reflection that can be seen on the glass window as a separate image in itself (barely visible) - i.e., showing the background inside the building from where the original photo was taken.

I've attached a sample photo I found online - although I haven't been able to find any clear/easy steps I can follow to accomplish this.  Does anyone have any photo adjustments/filters/other editing tools to suggest that can help with this?  Much appreciated!

[didiermazier]

This may not be an easy task. It will depend on the picture. You could try to check the channels, maybe after converting to lab mode…

[c.pfaffenbichler]

If you still have access to the location why not create two »proper« photographs and combine those? 

Do you have the RAW images? 

Could you post the image? 

[Earth Oliver]

you can't "extract" it, all you can do is slightly improve it like in your example.

[Francesco Della Peruta]

I agree with didiermazier, maybe start to work in lab mode, check the channels, try to apply some filters, masks, etc...