How to convert or rasterize AI subject / sky mask?

[sdinweoinasd9384152]

I work with bracketed images. I created an AI subject or sky mask for one of the bracketed images. Now I want to copy and paste this mask to the other images in the bracketed series, but I get a warning that the AI has to recompute the mask. This would be very bad since the bracketed images will be further processed in another software for an HDR effect, and if the AI computes the mask differently for each bracket, then this will ruin the HDR processing.

I want to be able to convert the AI mask into a static, fixed, rasterized, mask so that I can copy the exact same mask to the other images. How can I do this, other than to skip the AI mask and draw it manually with the brush tool?

[Todd Shaner]

Simply apply the Select Sky mask and settings to the HDR output file from the other app. No need to apply it to the bracketed image files. In fact doing so restricts you post editing options inside LrC for the sky.

[sdinweoinasd9384152]

Sorry, but that doesn't help with what I'm trying to do.

I want to apply the same mask to each bracketed raw file before exporting them to TIF and then do the HDR process with the TIF files in the other software.

I'm masking windows of an interior room to bring the highlights down. If I do not do this to the RAW bracketed images before exporting  to TIF from Lightroom, then the windows are completely blown out in the HDR output file from the other software. Importing the output file back into Lightroom and then applying the mask afterwards will not save the details in the window, as the details in the window are already lost.

How can I convert the Lightroom AI mask into a static, fixed, rasterized mask so that I can copy the exact same mask to the other images in the bracket series?

Thanks

[sdinweoinasd9384152]

Also, this does not necessarily have to be only for interior windows. It could be for any type of image where masking is needed for saving or editing details in bracketed images for export to another software for HDR processing.

Lightroom does a good job of noise / CA reduction to raw files, before exporting to other software for further editing.

Not being able to apply the same Lightorom AI generated mask to other bracketed images makes the tool unusable.

[sdinweoinasd9384152]

What I mean by HDR output file is not an actual HDR format file type, but a TIF output from a software that does HDR processing from bracketed images.

[johnrellis]

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Use the Copy Settings plugin to copy the mask to the other photos, checking the option Original Sky And Subject Masks:

[richardplondon]

IMO is not only unnecessary, but counterproductive to "correct" tones for submission to HDR processing.

IOW those real luminance differences between the interior and the exterior lighting need to pass unmodified into the HDR workflow, and then they can be coherently merged, and then that merge will be a full and coherent tonal representation of the actual scene, and that will allow these very contrasting light levels to be "tamed" for output: typically either by a "tone mapping" method, or an "exposure fusion" method.

[Todd Shaner]

"I'm masking windows of an interior room to bring the highlights down. If I do not do this to the RAW bracketed images before exporting to TIF from Lightroom, then the windows are completely blown out in the HDR output file from the other software."

If the bracket set was properly shot there should be no need to edit the raw files before exporting to TIFF for editing in the external HDR app. By that I mean the lowest exposure image file should have no clipped highlights with no adjustments inside LrC. If that's not the case then you need to shoot a wider bracket that includes lower exposure image files. You can use RawDigger free trial to check for highlight and shadow clipping in your raw file bracket set.

https://www.rawdigger.com/download

[sdinweoinasd9384152]

I'm processing thousands of 3 shot brackets for panoramas, and they all need to be shot with exactly the same number of brackets and exposure range for the batch processing in other software to function. I can't increase the bracket range for specific panoramas that need a wider range. Some of the images are from very dark interiors with an extremely sunny window. I have to expose for the interior, and I already know that only the image with the fastest exposure in the bracket will capture some detail from the window. The other 2 images in the bracket will be blown out.

Since I know about the blow out, I'm lowering the expsoure for the entire bracket to preserve as much detail as possible, then increasing the exposure in Lightroom, but I have to mask the window to exlude that increase to preserve the window.

I simply want to copy the exact same mask of the window to all 3 shots in the bracket. The Lightroom AI mask recomputes for each image, resulting in different masks.  The John Rellis plugin might do this, as a short term solution if I want to use the AI mask, as I don't see any other way to do it other than to not use the AI.

Lasso + feathering tool for masking would also really help for geometric masks, which was probably requested for since forever.

[Jao vdL]

"Since I know about the blow out, I'm lowering the expsoure for the entire bracket to preserve as much detail as possible, then increasing the exposure in Lightroom, but I have to mask the window to exlude that increase to preserve the window."

Your problem is in bold. You should simply NOT increase the exposure in Lightroom but just export the brackets directly and merge those (dark looking except for the windows) images in your HDR software. Your final image will come out looking fine. You might even want to dial in a low contrast profile such as camera neutral to help your HDR software but usually it can deal with whatever tone curve was applied. You DO NOT EVER want to apply local edits to bracketed shots that go into HDR merging.

[sdinweoinasd9384152]

I MUST increase the exposure in Lightroom by the same amount that I reduced the exposure in the camera. That is such the way it is with the workflow to get the same final exposure between images that were shot with different exposures. It is a batch process, and the software's HDR effect profile needs similar exposures to result in similar outputs. The software inputs TIF files. I'm simply preserving as much detail as possible in the windows, and masking the windows to exclude the increase in exposure in Lightroom helps this.

Local edits to bracketed images are competely fine when exporting them to the HDR software, as long as the edits are exactly the same amounts to exactly the same pixels in all images in the bracketed series.

[Todd Shaner]

"I'm processing thousands of 3 shot brackets for panoramas, and they all need to be shot with exactly the same number of brackets and exposure range for the batch processing in other software to function. I can't increase the bracket range for specific panoramas that need a wider range."

Using the suggested 2 EV Bracket (-2, 0 +2) you can only cover a 4 EV dynamic range without highlight clipping. I highly suggest you download the RawDigger free trial and check the lowest exposure image file in the bracket sets that require more adjustment. You will most likely find they contain significant highlight clipping in the brighteset areas (i.e. windows). Clipped highlights are not recoverable using any software. Also why must the bracket sets have the same number of brackets and exposure range? LrC can batch Photo Merge HDR without these restrictions. What HDR app are you using?

Just out of curiosity I tried Select Sky on a number interior shots that have bright windows. In almost every case 'No Sky Detected' or only a very small window area was selected. The Select Sky AI clearly isn't designed for detecting bright windows. Have you actually used this succesfully with a number of different bracket sets?

[sdinweoinasd9384152]

These aren't helpful recommendations. I simply want to copy the same AI mask to mulitple bracketed images.

As I mentioned earlier, I cannot increase the bracket range because of the workflow. I already know there is clipping in the windows. That is why when a panorama is in front of a window, I simply decrease the exposure in the camera by 1/3 or 2/3 step (compared to the exposure at other places deeper into the interior where the windows are not visible), and the window is captured in the fastest image in the bracket series. Then in Lightroom I increase the exposure by the same 1/3 or 2/3 step that I decreased in the camera. I mask the windows to exclude them from such an increase to preserve them.

[Todd Shaner]

"I simply decrease the exposure in the camera by 1/3 or 2/3 step (compared to the exposure at other places deeper into the interior where the windows are not visible), and the window is captured in the fastest image in the bracket series."

In most cases the windows will be much brighter than 1/3 to 2/3 EV. You are working blind and not following my suggestions. LrC and PS/ACR apply a camera profile to the image data making it impossible to determine the actual raw data.clipping in those apps. Please download RawDigger and examine some of those bracket sets that required unerexposure. This is the only way to determine if there is raw data highlight clipping, which is not recoverable. What you should be doing for those lighting conditions is to shoot a five bracket set (-4, -2, 0, +2, +4). Your HDR app should be able to batch process both three bracket and five bracket sets with no issues. If not then I suggest you look for an HDR app that can. LrC can do this type of batch processing using Auto-Stack By Capture Time and then CTRL + SHIFT + H keys to start the batch process.

[sdinweoinasd9384152]

When the window frame is completely free of obstructions and surrounded by a uniform surface, the Subject AI tool seems to correctly select the entire window frame. Although it varies between whether or not the window sill or other objects near the window.

[Bob Somrak]

Use John Ellis's ANY CROP plugin.  It will do the copy of the Sky/Subject mask without recomputing.

https://johnrellis.com/lightroom/anycrop.htm

[Bob Somrak]

My mistake, I meant his COPY SETTINGS  plugin

https://johnrellis.com/lightroom/copysettings.htm

[GoldingD]

Clarify this for us.

Are you correcting all the frames in your bracket before stitching them in your HDR software?

Correcting exposure, etc?

If do, that is amazingly wrong. utterly useless.

Also, if you have one or two frames in your bracket that are so far out of exposure, that they pile way up on the left or right in the histogram, with little usable data, then they should be excluded from the bracket, they are of no value to the process. 

some exemplers might help, we may be misreading what youor workflow is.

[sdinweoinasd9384152]

I really don't understand what you mean that what I'm doing is utterly useless.

How is it useless to adjust exposure before exporting RAW to TIF?

The HDR software inputs TIF or JPG. If the RAW isn't adjusted before exporting to TIF, then the TIF will be clipped in the wrong places.

The window from the interior is only 10% to 20% of some of the panorama points. I am adjusting the exposure for the interior because the windows are less important than the interior. The bright windows will be clipped in the 2 longest exposures in the bracket series because the difference in light is extreme compared to the dark interior. The bracket range cannot be increased because of the workflow.

Are you saying that this is utterly useless work, so then I should simply not take the photo and abandon the work? Or should I simply not shoot the bracket towards the window and not be able to stitch a complete panorama?

[Jao vdL]

> How is it useless to adjust exposure before exporting RAW to TIF?

You shouldn't be increasing the exposure slider on any raw file. The only thing you should worry about is blowing out highlight elements. DO NOT worry about clipping on the left side of the histogram. It DOES NOT exist. It is a myth. In digital imaging, all you need to do is not blow out the highlights and make sure the file has enough bit precision to cover the entire dynamic range, which for typically 12 or 14-bit raw originals means 16 bits export. You need to feed your HDR software as close to the actual exposures as possible and not adjust any of them. Using this information and the exposure metadata in the multiple files (which is why you don't want to touch the exposure sliders as you ruin that info!) it can recover the actual luminance of each pixel in your image by fitting the image data in the files from your multiple exposures and obtain a response curve that describes the tiff data. Basically it recovers the tone curves for your raw conversion engine. This allows it to then accurately recover the actual scene info by combining the multiple exposure images using this fitted tone curve and constructing a linear image again. It is best to do this from raw images as they are already linear in luminance so you don't have to do this but it can be done from jpeg/tiff to by the fit I just described but not all HDR software can work from raw. This process goes wrong if you adjust the exposure slider on a subset of the images and your HDR program will come up with luminance values for those images you adjusted that are a stop off which can cause issues in panorama stitching. Worse if you do local edits, the luminance input for those areas in the image is off from what it really is in relation to the rest of the image which can cause blooming artefacts in the final tone mapping from the HDR file.

It is simply best to feed the HDR combining algorithm files that are as close to scene referred as possible. Raw is best (like Lightroom's built-in HDR combining uses) but in absence of that, flatly developed tiff is what you want with certainly no local edits. If you need local edits, do them after the HDR combining step or after the tone mapping steps.

[Jao vdL]

And to be clear, it is NOT a problem to blow out highlights on the overexposed raw brackets. The only problem is when all your brackets are overexposed. If you have at least one image that has the window highlight correctly exposed, your HDR software will use that image for that part. It is not a problem if the other images have that part blown out.

[GoldingD]

It is useless to make any tonality adjustments before the HDR merge, whole point is to combine different exposures to get a longer dynamic range. In LrC that could be a moot point as LrC Merge Photo HDR would ignore those edits (useless)  In an external HDR editor that could/would be damaging to the process. (amazingly wrong), instead of merging, say three exposures at -2, 0, and +2 evf, you would then be merging 0,0,0 delta evf. You will loose much of the shadows and hilites that could have been preserved.