Fixing photographs (e.g. travel snaps) (ii)

3︎⃣ Fixing light with B&W

There are some images which contain shafts of light. Sometimes this light helps highlight certain objects in the photograph, be it as hard light or soft light. Consider the following photo of a viking carving from the Viking Ship Museum in Oslo. There are some nice shadows caused by the light streaming in from the right side of the scene. One way to reduce the effects of light is to convert the photograph to black-and-white.

By suppressing the role colour plays in the image, the eyes become more fixated on the fine details, and less on the light and shadows.

4︎⃣ Improving on sharpness

Sometimes it is impossible to take a photograph with enough sharpness. Tweaking the sharpness just slightly can help bring an extra crispness to an image. This is especially true in macro photographs, or photographs with fine detail. If the image is blurry, there is every likelihood that it can not be salvaged. There is only so much magic that can be performed by image processing. Here is a close-up of some water droplets on a leaf.

If we filter the image using some unsharp masking to sharpen the image, we get:

5︎⃣ Saturating colour

Photographs of scenes containing vivid colour may sometimes appear quite dull, or maybe you want to boost the colour in the scene. By adjusting the colour balance, or manipulating the colour histogram, it is possible to boost the colours in a photograph, although they may end up “unrealistic” colours in the processed image. Here is a street scene of some colourful houses in Bergen, Norway.

Here the image has been processed with a simple contrast adjustment, although the blue parts of the sky have all but disappeared.

Fixing photographs (e.g. travel snaps) (i)

When travelling, it is not always possible to get a perfect photograph. You can’t control the weather – sometimes it is too sunny, and other times there is not enough light. So the option of course is to modify the photographs in some way, fixing what is considered “unaesthetic”. The problem lies in the fact that cameras, as good as they are, don’t always capture a scene the way human eyes do. Your eyes, and brain correct for many things that aren’t possible with a camera. Besides which we are all tempted to make photographs look brighter – a legacy of the filters in apps like Instagram. Should we fix photographs? It’s one of the reasons the RAW file format exists, so we can easily modify an images characteristics. At the end of the day, we fix photographs to make them more aesthetically pleasing. I don’t own a copy of Photoshop, so I don’t spend copious hours editing my photographs, it’s usually a matter of adjusting the contrast, or performing some sharpening.

There is of course the adage that photographs shouldn’t be modified too much. I think performing hundreds of tweaks on a photograph results in an over-processed image that may not really represent what the scene actually looked like. A couple of fixes to improve the aesthetic appeal?

So what sort of fixes can be done?

1︎⃣ Fixing for contrast issues

Sometimes its not possible to take a photograph with the right amount of contrast. In an ideal world, the histogram of a “good” photograph should be uniformly distributed. Sometimes, there are things like the sky being overcast that get in the way. Consider the following photo, which I took from a moving train using shutter-priority with an overcast sky.

A lack of contrast

The photograph seems quite nice right? Does it truly reflect the scene I encountered? Likely not quite. If we investigate the histogram (the intensity histogram), we notice that there is one large peak towards the low end of the spectrum. There is also a small spike near the higher intensity regions, most likely related to the light regions such as the sky.

So now if we stretch the histogram, the contrast in the image will improve, and the photograph becomes more aesthetically pleasing, with much brighter tones.

Improving contrast

2︎⃣ Fixing for straight lines

In the real world, the lines of buildings are most often straight. The problem with lenses is that they are curved, and sometimes this impacts the form of photograph being acquired. The wider the lens, the more straight lines converse to the centre of the image. The worse case scenario are fish-eye lenses, which can have a field of view of up to 180°, and result in a barrel distortion. Take a photograph of a building, and the building will appear distorted. Human eyes compensate for this with the knowledge that it is a building, and its sides should be parallel – they do not consciously notice converging vertical lines. However when you view a photograph, things are perceived differently – it often appears as though a building is leaning backwards. Here is an photograph of a building in Bergen, Norway.

Performing a perspective correction creates an image where the vertical lines of the building are truly vertical. The downside is of course that the lower portion of the image has been compressed, so if the plan is to remove distortion in this manner, make sure to allow enough foreground in the image. Obviously it would be better to avoid these problems when photographing buildings.