Skip to main content
B
beausono
Participant
November 14, 2024
Question

Importing an 8-bit JPG image with sRGB color space into LrC Develop module

  • November 14, 2024
  • 3 replies
  • 515 views

Hi!

 

When I import a JPG image (8 bits) with sRGB color space in Ligtroom Classic (development module) :

 

1) Will Lightromm Classic convert the image color space from sRGB to Prophoto or does Lightroom Classic process the image in its original color space which is sRGB?

 

2) Is Ligtroom working in 16 bits with a JPG witch is a 8 bits format?

 

Thank you

Normand

 

This topic has been closed for replies.

3 replies

B
beausonoAuthor
Participant
November 15, 2024

 Thank you for your comments,

 

I think I have to talk to an Adobe Engineer, but I dont know how.

 

Normand

 

Conrad_C
Community Expert
Conrad_CCommunity Expert
Community Expert
November 14, 2024

Although Lightroom Classic isn’t going to alter or convert the original itself, I think the Develop module does work in ProPhoto RGB / gamma 1.8 (Melissa RGB). The only way to preserve the color appearance of an sRGB image in there would be to convert its color to Melissa RGB on the fly while in the Develop module.

 

I do think that Lightroom Classic is also doing an on-the-fly conversion of that image to 16 bits per channel in the Develop module only, again just for editing. The reason is that if image data is both converted to a color space as large as ProPhoto RGB but kept as 8 bits/channel, it will be difficult to avoid posterization/banding. So I’d be surprised if it didn’t edit that at 16 bits/channel.

 

So…for an sRGB original in JPG format at 8 bits/channel…

Library module: You see a preview generated from the original.

Develop module: You see an on-the-fly conversion to Melissa RGB at 16 bits/channel.

Export: The edited wide gamut, high bit depth Develop module data is converted to whatever color space and bit depth you asked for in Export options.

DdeGannes
Community Expert
DdeGannesCommunity Expert
Community Expert
November 15, 2024

@Conrad_C , I do not normally work on editing of jpeg files with sRGB color space so I cannot speak to your concept of LrC using  Melissa RGB to display jpeg files in the develop module.

My thinking is jpeg files in have a imbeded color space and there is no way improve the image edits can be applied to the image but there will be no enhancement to the color space.

Just my thoughts, I am open to any info you can provide.

PS. Not to worry I am now clear in my mind the color profile sRGB, Adobe RGB and Pro Photo RGB affects how the image is displayed in various applications.

 

Regards, Denis: iMac 27” mid-2015, macOS 11.7.10 Big Sur; 2TB SSD, 24 GB Ram, GPU 2 GB; LrC 12.5,; Lr 6.5, PS 24.7,; ACR 15.5,; (also Laptop Win 11, ver 24H2, LrC 15.0.1, PS 27.0; ) Camera Oly OM-D E-M1.
Conrad_C
Community Expert
Conrad_CCommunity Expert
Community Expert
November 15, 2024
quote

My thinking is jpeg files in have a imbeded color space and there is no way improve the image edits can be applied to the image but there will be no enhancement to the color space.

By @DdeGannes

 

I think all of that is correct. The image edits won’t be improved by changing the color space. I simply think conversion a necessary step given how Lightroom Classic works. Because if an image is sRGB and the Lightroom Classic working color space is something else, the image colors must be converted to the working space or the colors won’t look right when editing.

 

In Photoshop, there are all kinds of choices and options for the working color space and how to convert into it (or not). Lightroom Classic doesn‘t offer any of those options. So how is Lightroom Classic going to handle images of different color spaces?

 

I think what Lightroom Classic does is similar to if Photoshop was set up with the color settings in the picture below:

  • The working color space is locked to ProPhoto RGB. 
  • If you open/import an image that is not ProPhoto RGB, the application converts the image to ProPhoto RGB without asking or notifying, it just does it. There is no change to the appearance or quality of the colors. It’s just a necessary conversion to keep image color appearance consistent while editing in the working space.

 

    Per Berntsen
    Community Expert
    Per BerntsenCommunity Expert
    Community Expert
    November 14, 2024

    LrC uses non-destructive parametric editing, which means that it never touches the originals. All the work you do is done on previews created by LrC. 

    Edits are written to the catalog as text instructions which are applied to a new image when exporting or printing.

    So there is no conversion of color space involved, but LrC uses a variant of ProPhoto (Melissa RGB) as its internal working space.

     

    I don't know how many bits are used for editing, but I would assume 16.

    Not sure how important bit depth is, since the editing is non-destructive.

    Here's an article about color management in Lightroom. It's 17 years old, but I believe it is still correct.

    http://digitaldog.net/files/18Color%20Management%20in%20Lightroom.pdf

    B
    beausonoAuthor
    Participant
    November 14, 2024

    A RAW format doesn't have a rendered color pace and the preview in Lightroomn of a RAW format is in Melissa RGB, .

     

    Is that correct : with a rendered RGB images (JPG in sRVB), lightroom will create a preview with Melissa RVB? Is it a king on conversion from sRVB to Melissa color space?

    Terms & ConditionsAccessibility statement
    Using the community Terms of use Privacy Cookie preferences Do not sell or share my personal information ad choicesAdChoices