Thursday, February 23, 2017

How to run the PhotoFlow GIMP plug-in under Linux using the AppImage packages

Yesterday I have briefly described the new PhotoFlow GIMP plug-in. In this follow-up, I will show how to run GIMP and the PhF plug-in under Linux using the AppImage packages.

The latest GIMP and PhotoFlow AppImages can be downloaded respectively from here and here (you need to grab the most recent version). In the following I will assume that the AppImages have been downloaded into the $HOME/Applications folder, but any other folder on your filesystem is equally good...

In order to start the GIMP AppImage and let it find and use PhotoFlow for opening the RAW files and/or run as a filter on the existing layer data, open a terminal and type the following:

    export PHOTOFLOW_PATH=$HOME/Applications/photoflow.AppImage
    $HOME/Applications/gimp.AppImage

Of course you need to replace the paths of the photoflow and gimp AppImages with their actual paths and full names on your system...

The first line with the environment variable assignment is used to tell GIMP where to look for the PhotoFlow executable. The second line starts GIMP from the AppImage. You can also pass a file name as parameter to the GIMP AppImage, just like with the standard GIMP. The PhF plug-in also allows to directly open .PFI files with GIMP, in case you need to do so...

Wednesday, February 22, 2017

The new PhotoFlow GIMP plug-in interface

Recently I have been working on a complete re-write of the PhotoFlow GIMP plug-in interface.

The new plug-in code is a simple wrapper that saves and loads the image data into temporary floating point TIFF files, and then invokes the standard photoflow executable with those TIFF files as parameters.  It also saves and retrieves the accompanying PFI files with the processing parameters that get stored in the GIMP layer meta-data.

Monday, October 10, 2016

Non-destructive Lab editing with GIMP and the PhotoFlow plug-in

Since a while PhotoFlow is also available in the form of a GIMP plug-in. It means that PhotoFlow can be used directly within GIMP, to open and process RAW images as well as to apply non-destructive editing to any GIMP layer.

The most simple way to use GIMP in combination with the PhotoFlow plug-in under Linux is to download and run the AppImage package that is hosted on the pixls.us web site. This screencast explains the details of how to run the GIMP AppImage and briefly introduces the tools that are provided with it.

One of the possibilities offered by the PhotoFlow GIMP plug-in is to apply non-destructive edits in Lab colorspace to any GIMP layer. The Lab colorspace (or better CIELab) is an alternative representation of the pixel data that, unlike RGB, separates the luminance information from the color information. It is therefore possible for example to adjust the luminance of the image without changing the color components, or to adjust the color saturation in a way that is more natural and pleasing than in RGB.

Let's see how this works in practice.

Monday, March 21, 2016

PhotoFlow version 0.2.6 released

A new PhotoFlow version 0.2.6 is out!

This new version comes with lots of new or improved features and an updated GUI, including a better layout of the filters controls and an handy lateral toolbox that provides shortcuts for some of the most commonly used filters:

The image in the preview area is courtesy of Andrea Katifes


Monday, December 7, 2015

New PhotoFlow version 0.2.5

A new PhotoFlow version 0.2.5 is out!

This version bring two new cool features that will make the creation of local masks even easier:

  • A path selection tool that creates a closed region by connecting user-defined control points with a spline curve. It also provides an optional smooth falloff edge for feathering the selection. The path selection tool is similar to the path mask in Darktable, and most of the source code is actually derived from Darktable.
    This tool is particularly useful to generate smooth layer opacity masks for local editing.
  • A smoothing option for the brush of freehand drawing tool, with an adjustable smoothness:

Monday, November 2, 2015

New PhotoFlow version 0.2.4 released

The next PhotoFlow version 0.2.4 is out!
This is a maintenance release, only providing bug fixes and no new features.
The complete changelog for version 0.2.4 can be found here.