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There's got to be a better way.

Posted: February 25th, 2021, 7:19 pm
by Marpel
Not sure what I am doing wrong or if it is the tool.

Trying to accomplish what I had described in another post.

With an image open, I opened the mask tool and generated a fairly straightforward mask (a couple light-ray type triangles using polygon), without any feathering. I saved that mask as an image and closed both images.

I then opened the mask file and an image and it was my intention to try the mask at various feathering distances, within the Brightness Transform, just to get an idea of the potential effect.

However, it seems every time I touched a button after the first feather application, the program opened a Feather time-remaining Dialogue and it went through the full feathering again, while counting down. For each time I had varied the feather (I was progressively enlarging the feather number to see which one worked best), it seemed the program calculated each prior feather attempt (so if I had done three variations, the Feather dialogue would open, time down, close, then immediately open, time down, close, then immediately open again and time down). Once I had arrived at what I thought may be the best, I pressed OK and a new image was generated (with some brightness added).

However, I found I did not like the feathering, so I double-clicked the thumbnail to re-open the Brightness Dialogue, with mask, but again the multiple Feathering Dialogue went through an open, time down, close etc lengthy process before the image and Dialogue opened.

I clicked on the Mask thumbnail to re-open the mask Dialogue and again had to sit through those same multiple Feather Dialogues. In fact, I became so frustrated at this point that I canceled the operation prior to completion.

Am I just not understanding things and doing something the wrong way??

Marv

Re: There's got to be a better way.

Posted: February 26th, 2021, 8:02 am
by jsachs
It might help if you could post a reduced-size version of the image you are working on.

The Mask Feather tool is usually very fast as long as the mask has not already been feathered, so as long as you don't finalize the mask or try to re-feather a soft mask, you should be able to move the slider around without triggering a long operation.

If you are trying to simulate crepuscular rays, I suggest using the Gradient/Sweep transformation instead of a mask. I have attached a workspace script with a sample of how to do this -- when you open the script, just supply the name of the image you want to apply it to. You can adjust the Amount and locations of the rays by editing the Sweep Gradient transformation. When working on the color line, it may be useful to widen the dialog box to give yourself more working room. You can also drag the radial lines to reposition them although you can't drag one past another.
Crepuscular Rays.zip
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Re: There's got to be a better way.

Posted: February 26th, 2021, 10:21 am
by den
...For beams or rays, I will:

1) Take a beam sky/cloud image from my library that I have accumulated over the years [or search the internet for a free image of preference] and extract its Luminance channel.

2) Change this image's contrast about a 50% gray tone Luminance to preference.

3) then Composite-Hard Light or Soft Light blend with a 4 pt Perspective alignment; adjusting points and Overlay amount to preference where the image to be beamed is the Input.

With this workflow, it is easy to change the 2) contrast; the amount applied to the desired image; and adjust the shape and location of the beams.
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...den...

Re: There's got to be a better way.

Posted: February 27th, 2021, 7:05 pm
by Marpel
Jonathan and Den,

Thanks for the help on this. I will have to do some reading/understanding of the info you both have provided.

In the meantime, I have attached a sample image. I have a few of these, with differing light rays, but I think this gives a good idea. Some of the others have the rays crossing areas of much different tones, which, as I previously noted, makes a conventional mask a bit difficult. And as you can see in this image, especially the predominant ray that starts at the point and goes towards the lower left, the start of the ray is less feathered than the end (which is why I was asking about feathering related to mask width).

Marv

Re: There's got to be a better way.

Posted: February 27th, 2021, 7:10 pm
by Marpel
Should have mentioned in the post I just submitted,. The reason I am trying to make some masks for this, and other similar image, is I wish to brighten some of the rays already in the image. Not that I wish to introduce rays that were not initially present.

Marv

Re: There's got to be a better way.

Posted: February 28th, 2021, 3:26 am
by den
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Blend-ColorDodge with an image area mask of the foreground rays could be used to increase their contrast; followed with Selective Correct to decrease/darken a Cyan color cast...
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...den...

Re: There's got to be a better way.

Posted: February 28th, 2021, 7:29 am
by jsachs
How about converting the image to 8-bit B&W so it can be used as a mask (or use the Mask Brightness Curve tool to create a mask based on the brightness of the image) and then painting out the parts you don't want to mask.

Re: There's got to be a better way.

Posted: March 1st, 2021, 7:12 am
by den
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Another possibility to prevent a strong cyan color cast that the Blend-ColorDodge creates is to Extract the original image into its H, S, and V channels; perform the Blend-ColorDodge step on the V channel with an image area mask of the foreground rays; then re-Combine the H and S channels with the modified V channel...
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It is not clear to me what is intended with the lower right portion of the image so I included it in the image area mask. For illustration, the Amount of the Blend-ColorDodge was set at 100% which may be too much.

...den...

Re: There's got to be a better way.

Posted: March 1st, 2021, 9:12 am
by den
...
Instead of using Blend-ColorDodge to change the V channel; try Filter in Additive mode with a 1.75 exposure and the area mask having a large edge radius to cast illumination from the increased brightness of the rays...
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...den...

Re: There's got to be a better way.

Posted: March 1st, 2021, 8:38 pm
by Marpel
Thank you Den and Jonathan for the continued advice.

I must say, though, that much of what you speak is like me listening to a NASA scientist explaining the technical side of how the latest Mars projectile defeats Earth's atmosphere, travels a gazillion miles at warp speed and remotely lands gently on the red planet.

So, I will take some time and sort through all the information and give the ideas a try. I will start with what appears the simplest and convert the image to a black and white mask, with a little painting out of the unneeded areas. Seems like I should have thought of that, myself.

Marv