AP layers

[jackamus]

Why can't I have two layers with the same colour photo except the top one has been converted greyscale?

 

What I want to achieve is to convert the top layer B/W photo with 'Detect' edges, remove the background with the 'Flood erase' tool and to then view it on top of the coloured photo.

[MEB]

Hi jackamus,

You can. To convert the top layer to black and white you can use a Black and White adjustment. Without seeing the image you are working with it's hard to advise what's the best method to select and remove the areas you don't want. There's several ways to achieve it, some will give you best results depending on the subject of the image.

[jackamus]

Are you saying I must use an adjustment layer? I don't have a problem about removing unwanted areas.

[MEB]

Yes, if you use an adjustment layer you can control how the colour conversion will be performed changing the colour sliders in the dialog. When you are happy with the result simply press the Merge button on the top of the dialog to merge the result with the layer, or close the dialog to leave it as an adjustment layer.