Rob Shea Photography

Color Swap with ImageMagick

While exploring ways to simplify the infrared workflow in Lightroom, I considered writing a Lightroom plug-in. This plug-in would replace the round-trip to Photoshop, by performing a red/blue color swap, and then returning the output to Lightroom.

Ultimately, the Local Hue Adjustment and LUT (upcoming post) methods provide a better infrared workflow in Lightroom, since they do not create an extra PSD or TIFF file in addition to the original raw file.

For this plugin, I would have leveraged ImageMagick, the command line image editor, to perform the color swap. This could be done via a channel swap, swapping the reds and the blues, or by inverting the layer and blending it with the original.

Input white balanced 590nm infrared image
Input white balanced 590nm infrared image

ImageMagick output with channel swap
ImageMagick output with channel swap

ImageMagick output with invert blend
ImageMagick output with invert blend

Here are the ImageMagick commands to perform these actions.

Channel Swap via ImageMagick

magick convert input.tif -separate -swap 0,2 -combine output.tif

Invert Blend via ImageMagick

magick convert input.tif ( -clone 0 -negate ) -compose Hue -composite output.tif

While I won’t continue working on this as a Lightroom plugin, I wanted to share this progress. If AI ever gets savvy enough to set the white balance on an infrared image, then this could be used to batch processing infrared images.

LifePixel Infrared Camera Conversions