Happy Dusshera

I stepped out to buy a loaf of bread on Saturday and found a parking apron taken up by a trio busy stringing marigolds into streamers. Of course, the time-keeper in my head told me, “Tomorrow is dusshera.” It wasn’t very easy to track this year, with no lights, no festivities, no night-long dances. But it was hard to forget too, with all the sighing and complaining from friends and family about missing everything this year. I didn’t actually, I’m a happy bear these days. I’m a day or two late, but a happy dusshera to you.

But while lost in uffish contemplation of these photos snapped off quickly with my phone, a monstrous jabberwock raised its head. Do you recognize a subtle bit of structural racism here? Let me explain. A phone camera is no longer the simple light catching device that a camera was forty years ago. The image is mediated by software, and the huge improvement in this decade has been due to the addition of AI to the mix. That tweaks the exposure and colour according to optimizations it has been trained to use. Many of these improvements involve recognizing and enhancing faces. Just check your photos from five years back, and you’ll see how much better faces look in recent photos. I say usually, because it depends on the skin colour.

The AI is trained on data sets selected by Google, and these are largely biased to lighter skin colours. See, for example, a photo taken three years ago, by a six year old phone, in Madrid’s Atocha station. I have taken a random face from the shadows and inset it to show how well the AI has captured that. All I did was to increase the overall illumination in the inset. See the subtlety with which the details and shadows are rendered. Compare that to the inset face (with the same tweak for overall illumination) visible in the photo above that: the AI has rendered the bamboo framework in the background better than the face. This comparison shows that it is not light or darkness that makes a difference; it is algorithmic bias. It took me a bit of work on the featured photo to make the face visible. It is because of this bias that a DSLR or a good bridge camera still remains superior to a smart phone for street photography in India and most of the world.

Camera or phone camera?

I made the trip to Shillong by an airline which charges high and behaves like a cheap airline. The baggage rules were so awful that if it hadn’t given the fastest routing to my destination I wouldn’t have taken it. How could I cut down my baggage? I cut down much, and, after much thought I decided to sacrifice my camera. I’d used both my camera and phone extensively during my trip to China and realized that a smartphone camera is pretty good.

On my phone the sensor which captures the image is about the same size as that in my camera. Phone cameras use CMOS chips, which are more noisy and somewhat less sensitive than the CCD sensors common in cameras. My phone has a fixed wide angle f2.0 lens. The relatively wide aperture means that it focuses a large fraction of the light that it receives on to the sensor. However the lens is tiny, so the amount of light it captures is very much smaller than what the camera gets. The combination of small lens and CMOS sensor means that low-light or strong contrasts should come out badly, if everything else were the same.

But other things are not equal. Phone manufacturers have paid more attention to modern computational imaging than almost every camera manufacturer. As a result, I often find that the out-of-box image from my phone is better than that from my camera. Even image stabilization on my phone seems to be better than in my camera. For those who care, I could pull RAW image out of my phone if I wanted. (Why would I, when phones have more versatile software than commercial image processors?) In defense of cameras, I must say that my camera was launched almost three years before my phone. Phones and cameras launched in the same year may compare differently. Of course, my images are only shared with friends or posted on blogs. If you are a professional photographer your standards will be very different.

So, with much second thoughts, I decided that on a trip with the clan I would probably not do the extreme photography that I might otherwise. So maybe I could leave my camera behind. Here are two photos that I took with my phone camera on this trip. The panorama in the featured photo is no better or worse than what I’d expected to get. It has no details in the shadows, and the telephone tower in the distance is definitely blurred. On the other hand, the butterfly has come out significantly better than I’d expected. Although the contrast is high, but the phone has captured texture both on the lit and dark sides of the stone. The image is sharp, and there is no difficulty in recognizing the Large Yeoman.

If only my phone camera had not been broken by the latest software update from the vendor, I would have ditched my camera for it more often, at least when I travel on work.