Masking question

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Marpel
Posts: 320
Joined: September 13th, 2009, 3:19 pm
What is the make/model of your primary camera?: Nikon D810
Location: Port Coquitlam, British Columbia

Masking question

Post by Marpel » August 28th, 2018, 1:39 am

A PWP 7 question.

I am trying to finesse some masks of flowers and other vegetation against various backgrounds (difference in colour, tone and sharpness). In the one I am currently working on, for the most part, a flower is mostly against a smooth, blurred background. When zoomed in significantly, the flower's edges, although the flower is in sharp focus, have a gradual feathering of about 3-4 pixels. This change is so subtle, in some areas it is difficult to distinguish exactly where the flower actually ends and the background starts. Of course, to state the obvious, at a a viewable resolution the flower looks sharp against the background.

I have tried all the masking tools, and they all seem to result in the same saw-toothed hard edged mask that sometimes does not include some of the feathered pixels or in some cases, will extend a bit into the background. The feather tool provides a less than satisfactory result.

Am I correct that, other than the curves tool, the masking tools do not have the ability to automatically feather a selection, based on colour/tone (in other words, if I have graduated image that goes from one colour at one end, to another colour at the other and the tool is clicked at one end, the mask will feather out towards the opposite end because the colour/tone changes the farther away it is)?

I am trying to place the masked objects into other images and the results look too "fake" to my eye, regardless of the tool/technique I employ. The new images will be printed up to 40 inches, so need to be believable from a close distance.

Any suggestions on tools/techniques would be appreciated.

As I have no familiarity with PWP 8, not sure if the masking tools are different/better and may solve my problem.

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jsachs
Posts: 1463
Joined: January 22nd, 2009, 11:03 pm

Re: Masking question

Post by jsachs » August 28th, 2018, 6:54 am

The color range mask tool also has built-in feathering.

If you have the patience, you will probably get the best results using the spline mask tool or possibly the freehand mask tool to trace around the edges of the flowers by hand, followed by feathering or blurring the mask a little.
Jonathan Sachs
Digital Light & Color

Marpel
Posts: 320
Joined: September 13th, 2009, 3:19 pm
What is the make/model of your primary camera?: Nikon D810
Location: Port Coquitlam, British Columbia

Re: Masking question

Post by Marpel » August 28th, 2018, 9:36 pm

Thanks, Jonathan, for the reply.

It actually never occurred to me that the colour range had feather capabilities. When I read your reply, I gave it a try and found it a bit confusing as I could not immediately figure out how each slider of the H,S,and V components affect the resultant feathering of the mask. I tried generating a gradient image of two markedly different hues and started the tool around the centre of the image, then moved each slider of the H,S and V components. Sometimes a feathering occurred and sometimes it did not. I guess I will have to play with it a bit to get the hang of it.

I have used the spline tool in the past, but those images had objects to be masked that were fairly round/smooth and fairly easy to use the tool on. Except for small objects that need masking, I find the freehand tool very time-consuming to use, so it is usually the last tool that I prefer. Perhaps I will go back to using the spline as it gives some of the smoothest results (although it does require some practice to get good).

Thanks again,

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jsachs
Posts: 1463
Joined: January 22nd, 2009, 11:03 pm

Re: Masking question

Post by jsachs » August 29th, 2018, 7:13 am

The trick to using the spline tool is to start by making a curve that crudely approximates the desired outline and then refining it by clicking repeatedly between the control points.
Jonathan Sachs
Digital Light & Color

Marpel
Posts: 320
Joined: September 13th, 2009, 3:19 pm
What is the make/model of your primary camera?: Nikon D810
Location: Port Coquitlam, British Columbia

Re: Masking question

Post by Marpel » August 29th, 2018, 7:29 pm

Funny enough, Jonathan, prior to reading your comment, I just spent the last hour or so using the spline tool on the petals of another couple flowers and it worked wonderfully (and you are bang on with the advice to click repeatedly between the control points). This tool has now become my favourite masking tool (and one of the benefits is the smooth edges that it produces). The work I was doing that caused this thread to start had way too many irregular edges and points to use a single method so it became frustratingly slow.

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