ISO profiles - marcapelini/RTProfileSelector GitHub Wiki

One more thing that you can have RTPS automatically do is apply a custom partial profile based on the an image's ISO value. The main purpose of this is to automatically apply noise-reduction settings in RawTherapee based on your camera's ISO vs. noise characteristics. This is done right after the main profile selection based on your rules, and just before any lens distortion correction is applied.

To use this feature you have to:

  • Create a number of partial profiles in RT with settings that you find appropriate for images with different noise levels
  • Create a camera-specific definition file to associate ISO values with your noise-reduction partial profiles
  • Open an image for which you think some degree of noise correction should be applied, and set the controls in RT to taste:

  • For noisy images, you may want to also change the demosaicing method. For higher noise images, I particularly like the igv algorithm:

  • To save a partial profile with the the settings you have selected, press CTRL and click the "Create processing profile" button. This will open the "Save Processing Parameters" dialogue, and you should give your profile a name:

Note in the image above that I have created a folder named "Noise Profiles" to place the custom profile. This is just a personal thing, as I like to have my noise profiles separated from other custom profiles that I have. It doesn't matter where you place your profile as long as it is somewhere within RTs custom profiles folder.

  • When you click "Ok" in the "Save Processing Parameters" dialogue, you will be presented another dialogue to select which settings to save in the file you just named. Since the purpose of this profile is to carry settings related to noise reduction and detail, here's my suggestion:

  • You probably will want to repeat the process above several times for images taken at different ISO settings (and different cameras), adjusting each one as you think best, and saving a partial profile named so that you know later what noise levels that profile is supposed to reduce. Here are the ones I have right now:

Associating ISO values and processing profiles

Now that you have a number of partial profiles for noise reduction, you can associate them with different ISO values, for different cameras.

  • Create a folder named "ISO Profiles" within RTPS' own folder
  • Create a file named iso.YOUR CAMERA MODEL.ini, where YOUR CAMERA MODEL must be the value reported in the Exif field "Camera Model Name" for your camera
  • Assign one of your noise partial profiles to different ISO values
  • The profile will be applied to any image of the same or greater ISO, so, with the ISO profile I created above for the GM1, if I open a photo taken at ISO 1600, RTPS will apply the settings from the "mid_noise_partial.pp3" file.
  • Note that, in my example below, images with an ISO value below 400 were't assigned a profile, so they will have none applied by RTPS.
  • Also note that I have included, before the file name, the folder name ("Noise Profiles") which I chose above when saving my profiles. If you saved yours at the root level of RT's custom profile folder, you only have to declare the .pp3 file name here, of course.
  • Lastly, I have programmed RTPS to always first look for the partial profiles in RT's custom folder and, if it can't find them there, to look in RTPS's own "ISO Profiles" folder, so you have two option of where to keep you noise partial profiles. Take your pick.

Here's an example for my Panasonic GM1:

Controlling which parameter groups to apply

For ISO-based profiles, RTPS works on the assumption that the .pp3 profiles that you have listed for application for each ISO value is a partial processing profile with only noise and detail related settings. In case that is not true, unexpected results can occur, with the parameters from the profile RTPS previously selected based you your rules being overwritten by the ISO-based "partial" profile. To prevent this from happening, you can declare a [ISO Profile Sections] section in RTProfileSelector.ini listing which sections from the selected partial .pp3 file will be actually copied from your ISO profiles to the final profile generated by RTPS. Here's an example of what I have in my RTProfileSelector.ini just to make sure only noise and detail-related settings will be overwritten:

[ISO Profile Sections]
Directional Pyramid Denoising=1
Impulse Denoising=1
RAW=1
RAW Bayer=1
RAW X-Trans
Sharpening=1

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