Reduce white background in art sketchbook (actionable)

[slowswim]

Hi,

I'm an artist who often draws in sketchbooks.  I've documented my sketchbooks by taking consistent digital photographs of each sketchbook page.  I have almost 600 images I need to alter at once.  I'm having a hard time finding a good, accurate and repeatable set of commands (through an "action" maybe?) to reduce the gray overcast the photographs have of the sketchbook drawings.  Some of the drawings have very fine line work I need to be mindful of when working with the images as I do not want to distort or lessen the drawing quality.  If anyone can offer some words of advice or suggestions, I would be very grateful.

see below for examples. These images have been reduces from 300 to 72 res for uploading purposes.

Thank you.

[Stephen_A_Marsh]

You can try the action in the following topic to remove white (there is the original Japanese version or the one that I adapted for English installations):

https://community.adobe.com/t5/photoshop-ecosystem-discussions/photoshop-needs-quot-color-to-alpha-q...

This method differs from simpler blend if slider or color range masks.

[Stephen_A_Marsh]

I think that I misunderstood you in my previous reply.

If you are just looking for repeatable tonal adjustments, then if you are happy with the result of the auto button in the Filter > Camera Raw filter (under Light), then this can be automated via a script (not an action which would record fixed values).

/*
https://community.adobe.com/t5/Photoshop/Is-there-any-jsx-to-execute-the-auto-tone-of-camera-raw/m-p/10167490#M207367
*/

/*
ACR and raw files would be covered by this topic post:
https://community.adobe.com/t5/photoshop/how-to-record-button-click-on-action/td-p/10858184
*/

autoCRF();

function autoCRF() {
  // Camera Raw Filter - Auto
  var desc1 = new ActionDescriptor();
  desc1.putBoolean(charIDToTypeID("AuTn"), true); // AuTn = Auto
  executeAction(stringIDToTypeID('Adobe Camera Raw Filter'), desc1, DialogModes.NO);
}

// or:

/*
(function () {
  // Camera Raw Filter - Auto
  var desc1 = new ActionDescriptor();
  desc1.putBoolean(charIDToTypeID("AuTn"), true); // AuTn = Auto
  executeAction(stringIDToTypeID('Adobe Camera Raw Filter'), desc1, DialogModes.NO);
})();
*/

Or if you prefer fixed Camera Raw Filter values, then record auto in an action.

You can also look at auto levels/curve options which can be recorded into an action if your lighting and exposure is pretty consistent. You could also use the Image > Adjustments > Shadows/Highlights or other adjustments as required (Selective Color > Whites).

[slowswim]

Hi Stephen, Thank you for the responses.  I will give these try and follow up with any questions. Best,

[Conrad_C · Accepted solution]

Because your images are captured consistently, a possible simple alternative is to customize the Auto button settings for a Levels or Curves adjustment layer. This would let you brighten the paper white simply by clicking the Auto button, which will apply your customized adjustment.

The steps below are basic. If you want more background about how the options work, read the following article by Bruce Fraser. Although it was written 22 years ago, it still works today. The advice about colors is mostly about photos, so that might not apply to these drawings.

Don’t Underestimate Photoshop’s Auto Color

Start by adding a Levels adjustment layer, then click the Properties panel menu and choose Auto Options.

Select Find Dark & Light Colors. (Or maybe for these drawings, if you are confident their white balance is consistent, Enhance Monochromatic Contrast might be just as good.) Also select Snap Neutral Midtones.

Increase the Highlights Clip value; the maximum is 9.99%. This shifts the white point down, making the lightest tones brighter. The reason I stopped at 6% is that higher values appeared to cause more unwanted highlight clipping (potential loss of paper detail), but if you aren’t concerned about that you can enter a value higher than mine. Select Save As Defaults (to make your changes stick and therefore alter what the Auto button does), and then click OK.

Because you changed the Auto button defaults, the next image should be a one-click deal. Open another image, add a Levels adjustment layer, and click Auto. It should apply your customized Highlights Clip default percentage, so if the image tonal levels are consistent with the earlier image, the customized Clip value should brighten the highlights in this image by the same amount as the previous image.

If you want to create an action for that so you can batch it, I tried recording it and it works. The second step below is where it records me clicking the Auto button.

 

[slowswim]

Hi Conrad, This is not only super helpful but easy to follow and solves my issue using simple in-house tools.  Thank you so much!! Best, John

[Stephen_A_Marsh]

Hi Conrad, This is not only super helpful but easy to follow and solves my issue using simple in-house tools.  Thank you so much!! Best, John

By @slowswim

I'll mark the reply from Conrad as the correct answer then.

[slowswim]

I have a follow up question.  Some visual effects still need to be mitigated.  The gray overcast has been for the most part reduced significantly in a desirable manner, however, the area around the sketchs remains gray to the point when it will be printed on a piece of white paper the sketch will have a gray box around it.  I should mention the whole goal here is to take all 560 some odd sketches into InDesign and create a book.  I will then print the physical book.  Back to the issue at hand.  The "gray box" around the sketchbook was a white background.  It has some shadows on it.  I'm ok the shadows.  I'm not OK with the gray hard edged box.  I think it would be accecptable to just fade the outside .5 - ~1" to pure white if there is an automated way to do this.  I have tried using a brush but I do not believe this can be automated.  I am investiaging the feather command but am not savy enough to tackle it yet or come up with a solution.  Any additional insight would be wonderful.  examples of Leveled images per Conrad's suggesion below.  Thank you.

 

[slowswim]

an example image on a white background with about 1" border around it.

[Conrad_C]

…I should mention the whole goal here is to take all 560 some odd sketches into InDesign and create a book.  I will then print the physical book.  Back to the issue at hand.  The "gray box" around the sketchbook was a white background.  It has some shadows on it.  I'm ok the shadows.  I'm not OK with the gray hard edged box.  I think it would be accecptable to just fade the outside .5 - ~1" to pure white if there is an automated way to do this.

By @slowswim

That’s good news that these are going to InDesign, and that you are OK feathering them. Those lead directly to this possible solution:

Do the feathering in InDesign. After adding the images to the layout, select all of them, open the Effects dialog box (you can find it by its “fx” icon in the Properties, Control, or Effects panels, or open the Object > Effects submenu), apply Basic Feather, and increase the Feather Width value until it isn’t quite feathering out the notebook or the spiral binding, as shown in the demo below.

If you want to adjust how tight the feathering is, adjust the Choke option. If you want to adjust the feathering value individually on each side, apply Directional Feather instead because it gives you separate controls for the Feather Widths for Top, Bottom, Left, and Right. I have a feeling Directional Feather is ultimately how you will do this, because of the flexibility.

That would be the basic way, but because you have hundreds of images to lay out, here’s what I would really recommend in InDesign:

1. Do a test to get the feather values right for most sample images, then define an Object Style using those Feather Width values.

2. Apply that object style to any frame that will contain an image, so that it takes on the feather values in one click.

3. You can start with one frame with the effect applied, then copy and paste that one frame to lay out the pages in advance, before adding images.

4. When you add images to any frames using this object style, they will all feather the images as defined by the object style.

5. If later you change your mind about the feather settings, just edit the Object Style, and because it’s applied to all the frames, they will all update at once.

If you realize that a few images don’t quite work right with the Feather Width value(s), you can either edit the object style to accomodate them, or, you can use the Effects dialog box to override the Feather Width value(s) for specific frames.

[slowswim]

Thanks again,  Conrad.  I will start setting thing up and trying it out.  Should I be placing these as PDFs or for the sake of file size, should I save them over as JPEGs?  Thanks again!

[Conrad_C]

InDesign will take them either way, so if it saves time and file size is not a major issue, you could just place them in whatever graphics format they are currently.

If you will be handing off a PDF file exported from InDesign, there are opportunities to apply some downsampling and compression to all images at once when you export to PDF, so that the PDF file is smaller. This might depend on which PDF standard the printing service wants to receive.