Color matching JPG to RAW file

[stevem38895022]

As a general rule, in my opinion, in-camera JPG's look "better" than unprocessed RAW images due to the in-camera processing by the super-secret algorithm used by Canon etc. Colors tend to be brighter, more saturated and probably a bit more contrast. Theoretically, one can achieve the same result in ACR by tweaking the various settings. Provided one has the skills to do so which, unfortunately, I do not. One of the avenues I explored was offsetting the RGB values ie compare the RGB values for the same point and adjust the RAW file in CC by the difference. So I want to move,say, the red value from 125 to 135 etc. There does not appear to be any way to do this, especially globally across the whole image.

Second option was to use color matching. I add the JPG as a layer into the RAW file (which I mean the RAW file is opened through ACR then opening CC without making adjustments). Use the JPG layer as source and RAW layer as target. This gets within a couple of points on the RGB which I can tweak with the intensity setting.

My question is this, does this compromise the RAW file quality by using an 8 bit source into an 16 bit target ?

Given the whole idea is to match the colors of the JPG in the higher quality RAW file.

It appear as there is something in this as adding the RAW file as a layer in the JPG file and doing the color matching really messes it up.

Any help or advice would be appreciated.

[TheDigitalDog]

stevem38895022  wrote

As a general rule, in my opinion, in-camera JPG's look "better" than unprocessed RAW images due to the in-camera processing by the super-secret algorithm used by Canon etc.

Before we answer your specific questions, please read this article (it's long but well worth it):

http://www.lumita.com/site_media/work/whitepapers/files/pscs3_rendering_image.pdf

The general rule isn't a rule and rendering the image is part of the process.

[stevem38895022]

Thanks, I read the article and the difference between scene-referred and out-referred is understood (mostly).  JPG's are rendered in-camera and RAW's are rendered in Photoshop.

The take away from the article is that working from the RAW file is far more preferable than using the JPG as it gives much more latitude for adjustment and correction (which is why I shoot in RAW+JPG).

For my purposes the Jay Maisel article was they key point. He is so good at his job that "The JPEGs directly from his camera are often what he wants; in fact, much of the time he instructs his assistant to simply “match the JPEG” when he processes Raw files for printing"

This is what I want to be able to do, at least in the first instance. I find the out of camera JPG pleasing and I want the RAW image to"match the JPG" as a starting point before looking at highlights, shadows etc which I can recover through ACR.

From the same article "Jay now shoots both Raw and JPEG at the same time. While he almost always has the correct exposure, the advantages of working with the Raw file in sharpening, scaling, and detail are still very much worth the effort."

The Color Matching I described above appears to meet my requirements in this regard. My concern is that it has a negative impact on picture quality (at least the 16 bit import from ACR).

[D Fosse]

This is a matter of policy.

The default settings in ACR and Lightroom are deliberately conservative. The main priority is to preserve as much of the original data as possible. The rest is up to you.

A "pleasing" image is naturally a priority for the camera manufacturer. They want to sell cameras.

[TheDigitalDog]

Ideally you want to stick with the raw data. The JPEG engine that processes the raw massively clips and compresses highlights. We often don't when editing the raw. This compression can clump midtones as much as 1 stop while compressing shadow details! People incorrectly state that raw has more highlight data but the fact is, the DR captured is an attribute of the capture system; it's all there in the raw but maybe not in a camera proceed JPEG.

A raw capture that's 10 or 11 stops of dynamic range can be compressed to 7 stops from this JPEG processing which is a significant amount of data and tonal loss! So when we hear people state that a raw has more DR than a JPEG, it's due to the poor rendering or handling of the data to create that JPEG. The rendering of this data and the reduction of dynamic range is from the JPEG engine that isn't handling the DR data that does exists as well as we can from the raw! Another reason to capture and render the raw data, assuming you care about how the image is rendered!

[NB, colourmanagement]

Hi Stevem

I’ll see if I can help here.

Definitely worth reading the recommended piece but, to your mind, it’s not answering your initial query.

1:

I think you appreciate that the processed RAW is superior to the JPEG, you made that decision already?

Watch out for any advice from the uninformed that the JPEG is fine. In many cases it’s unsuitable.

Quoting Martin Evening (esteemed Author of Adobe Photoshop for Photographers) switching from RAW to a Jpeg discards up to 83% or the original captured image info. You’d need to be in a hell of a rush to accept a compromise like that I feel.

2:

Beware, also, that there are pretty serious consequences to resizing a JPEG, so, even if you actually want a JPEG, you’re better off creating it from the RAW at the right size for the final use.

If you don’t know the final use and size or if you may want to repurpose the file later - then I suggest you process the RAW, save a tiff - as the archive file.  (ideally a layered tiff with the corrections as adjustment layers) .

Then when you need a certain size JPEG - just duplicate, flatten, resize, shapes and save as JPEG.

(I always recommend duplication before flattening, if you get distracted its easy to save the flattened file over the layered one and that’s not good.)

Back to the question: You wrote (about achieving a visual match to result achieved by the camera’s auto processing):

"Second option was to use color matching. I add the JPG as a layer into the RAW file (which I mean the RAW file is opened through ACR then opening CC without making adjustments). Use the JPG layer as source and RAW layer as target. This gets within a couple of points on the RGB which I can tweak with the intensity setting.

My question is this, does this compromise the RAW file quality by using an 8 bit source into an 16 bit target ?

Given the whole idea is to match the colors of the JPG in the higher quality RAW file.

It appear as there is something in this as adding the RAW file as a layer in the JPG file and doing the color matching really messes it up."

I expect you are effectively blending the JPEG data into the processed RAW - Is that what you mean? Don’t do that. As you have seen this potentially  “really messes it up”.

and, later:

"The Color Matching I described above appears to meet my requirements in this regard. My concern is that it has a negative impact on picture quality (at least the 16 bit import from ACR)."

I agree that it does have a negative impact on picture quality, your first method of matching colours by RGB values is far more worthwhile.

You’re right it can take a while to get as good as the guys who developed the camera’s auto process, but it can definitely be done. This is one of those cases where its really worthwhile putting the time into learning a skill. With time you’ll appreciate that a personally optimised file, dependent on use and image type - and taste - beats any auto processed result.

I hope this helps

if so, please do mark my reply as "helpful" and if you're OK now, please mark it as "correct" below, so others who have similar issues can see the solution

thanks

neil barstow, colourmanagement

[stevem38895022]

Thanks Neil,

You are on the same page as me, I want to keep the RAW as a base and process to JPEG only when I need to display or print.

The method is "Color Matching"  through the Adjustments menu and not a blend mode, at least not specifically on the JPG layer. It may be an informal blend carried out through the adjustment but I don't know how to confirm this.

The RGB shift method is certainly worthwhile but I have to find a method on how to do this. I making a number of assumptions in doing this, such as the color shift is uniform across the image but essentially I want to pick a specific point on the image and move the RGB by a set amount it from, say, 134,84,57 to 139,82,51 and apply that shift over the whole image.

And that's where I'm stuck, I can't find how to do it or, in fact, if it is even possible

[NB, colourmanagement]

Hi stevem,

In order to achieve what you want and for it to be totally adjustable down the line, I’d start out by using a curves adjustment layer and watching those numbers, that way what you do in moving a certain point is applied throughout the image to a varying extent.

Generally the rule is to try to apply "global" corrections to appearance because most often a caste etc is global. SO no selections needed normally.

You may also find that a “hue/saturation” layer helps you move forward.

I hope this helps

if so, please do mark my reply as "helpful" and if you're OK now, please mark it as "correct" below, so others who have similar issues can see the solution

thanks

neil barstow, colourmanagement