Question for the experts about masking/selection function

[OldRadioGuy]

Maybe you can tell me if I've been doing this incorrectly in the past few years. (The English-language manual is no help.)

For example, if I wanted to transform part of an image to black and white and leave a section in color, I have been using the Automask tool. A very nice tool, but no matter what the tolerance settings with a moderately complex image, it usually requires returning to the mask/selection and either adding or subtracting to get the precise mask/selection.

So, here's the sweep of the tool across a flower. Even though the green foliage frame is larger than the screencap shown, the circle/adjustment cannot be made any larger on this mouse movement (if that means anything to the mask/selection).

PL-Automask1.jpg

And here's the screen image after the mouse button has been released. The yellow arrow shows the motion of the mouse and the orange circles indicate errors in the mask/selection that have to be fixed with additional "+/-" applications of the Automask tool. (The tolerance on this was set at 0, but other tolerance settings were no better.)

PL-Automask2.jpg

I assume I am doing something wrong here, because this kind of masking/selection should be very quick.

A number of competitors are now using what they call Smart Selection (masking) for this kind of operation. The tool make an intelligent interpretation of what the user wants based on mouse movement. Below is example of a selection/mask made in less than two seconds. The yellow line and arrow show the motion of the mouse to achieve this. No additional tool application was required to achieve this perfect mask/selection.

BrandX.jpg

So, if I can't do this kind of operation in PL as efficiently, I'm faced with the decision about whether to use an alternative editor for masking/selection in my image work .

Hopefully, someone can give me the key to quicker automasking/selections in PL.

Thanks.

Bob

[bkh]

For example, if I wanted to transform part of an image to black and white and leave a section in color, I have been using the Automask tool. A very nice tool, but no matter what the tolerance settings with a moderately complex image, it usually requires returning to the mask/selection and either adding or subtracting to get the precise mask/selection.

That's quite normal for the automask tool — it makes its selection based upon absolute colour differences only.

So, here's the sweep of the tool across a flower. Even though the green foliage frame is larger than the screencap shown, the circle/adjustment cannot be made any larger on this mouse movement (if that means anything to the mask/selection).

The circle shown doesn't have anything to do with the selection range (I also find this confusing) but represents the tolerance setting of the tool. The tolerance is set depending on the distance between the current mouse position and the initial click position.

A number of competitors are now using what they call Smart Selection (masking) for this kind of operation. The tool make an intelligent interpretation of what the user wants based on mouse movement. Below is example of a selection/mask made in less than two seconds. The yellow line and arrow show the motion of the mouse to achieve this. No additional tool application was required to achieve this perfect mask/selection.

The equivalent of this should be the quick selection tool (at the same toolbar position as the automask) which was introduced in PL recently. That should work well with the flower.

Cheers

Burkhard.

[Herbert123]

With flowers, especially with this type of greenery in the background, the trick is to work in Lab mode: Flowers occupy quite obvious spaces in either a or b, and tend to be prime candidates to select through Lab. Lab is my favourite space to work in - extremely powerful.

Convert your image to Lab mode, and switch to the channel panel. Grab either the a or the b channel (depends a bit on the colour of the flowers), and convert it to a layer in the Channels panel (second button bottom channel panel). Examine which of the two stands out more.

Then, apply a curves adjustment, and crunch the greyscale values. Depending on the colour of the flowers (for example, with purple-ish flowers the b channel works well) you will have to add another curves and invert the greyscale values. Finally, apply a gaussian blur to remove the sharp edges. Done. This can be turned into an action.

Once you know how this works, a good selection can take less than half a minute. And you can always fine-tune this basic mask any way you wish.

I have included an example for you to have a look at! This example could be improved by adding more levels of blurring in regards to how some of the flowers are semi-focused, some completely blurred, and others sharp in focus. It's certainly not perfect - still, a very usable mask in less than a minute.

http://www.estructor.biz/testje/flowers.pld (right-mouse click to save)

Hope this helps a bit.

Suggestion for an upcoming version: I wish we could create a virtual layer out of a channel - that would save some space, and when we do some channel work this is automatically updated in the virtual copy as well. For example, <ctrl> click on the second button in the channel panel would create a virtual copy of the selected channel in the layer stack.

Btw, why aren't we allowed to upload more than 128kb? I would think 1mb to be a far more useful limit, because at times when I want to upload an example, this low upload limit forces me to resort to an external upload service, or, in this case, my own server.

[Hoogo]

With flowers, especially with this type of greenery in the background, the trick is to work in Lab mode...Grab either the a or the b channel...convert it to a layer in the Channels panel...apply a curves adjustment, and crunch the greyscale values...

This is one of the usual receipts of creating a mask from channels, and I usually prefer doing it by hand, path or channels, to using some kind of automatic tool.

Now some more complicated receipt for creating the best mask from channels:
Have a look at this plugin: Color cube, 32Bit only. It can show all the used colors of a picture in a 3D-cube. Load Bob's flower into PL and play with the tool.

You will see what Herbert already told: Flower and green occupy clearly different spaces within that cube of colors.

Rotate the cube and imagine the plane between flower and green. The distance to that plane would be the perfect mask from channels.

-Grab a purple and a green that would face each other in a right angle through the plane. I have chosen 191/56/90 and 113/189/49.
-Subtract the values. That gives 78/-133/41
-Go to the channel mixer, type in 78/-133/41 and adjust the constant.
-Go on with the curves.

That calculating is a lot of work, but it is useful for the moments with very little contrast between background and foreground. It can also be useful for bw-conversions or any other occasion where you want to enhance contrast between two colors. But then you should usually divide the values to avoid clipping in the channel mixer.

And this receipt also shows that Lab is not really a Wunderwaffe that deserves a lot of respect. YCbCr is very similar, can be done with the channel mixer and also shares the idea of isolating brightness from red-green and blue-yellow.

[Martin Huber]

While using channels is an all-purpose solution for selecting, these simple cases (and many more) are quite easily done with the Quick Selection Tool.
Just drag a rectangle around the flower. In your simple case this should be enough.

Martin