Colourising infra-red images

Infra-red photos taken with an infra-red filter (that cuts out the visible light) needs processing to produce a black an white image – without a filter you get false colour infra-red as the visible light also forms part of the image. The processing is done with a photo editor such as Photoshop:

  1. This is what you get out of the camera in infra red:
Out of the camera in infra red

2. Conversion to black and white with other processing gives this type of image:

Converted to black and white

I decided to experiment with different ways to add colour to infra-red images. Photoshop Elements has a feature, often used to add colour to old photographs, to colourise photos. This is the result:

Colourised infra-red image

Not too far from the original scene. The stubble in the field and the grasses in the foreground were quite yellow. Look at the trees though and some are showing green foliage and others the white foliage typical of infra-red photography. Below is a slider “before and After” comparison:


black and white
colourised

Inspired by the photos of the James Webb Telescope I thought I would try similar techniques to create a composite colour image. This is not as easy as it seems. I took 3 images at different infra-red wavelengths and tried adding one primary colour to each and blending the results. I found if the original blending was too good I ended up with the original black and white image!

I experimented with different techniques and the best I have got, so far, is this:

My own attempt at colourising using photoshop layers

Below I have another slider for “before and After” comparison:


black and white
colourised

A bit surreal though. I need to think some more about this and try different methods…

Author: Paul L.G. Morris

I am an amateur photographer whose photography is mostly of gardens, nature and the rural environment. My specialities are close-ups, panoramic views, or a combination of both that I call 'Nearscapes'. I work mostly for my own interest having closed my business PM Studios Ltd.