cricketballs.org

How accurate is this?

There are a number of challenges when trying to recreate real physical colours on screens. The biggest challenge is in the limited dynamic range of most screen displays, which makes it difficult to visualise high contrast scenarios (i.e. where the ball is much darker or much lighter than the background). Another challenge is in the limited range of colours which screens can display, compared to the real world. Furthermore, screens differ from one another and we have to assume some characteristics (sRGB, for those who are interested in the technicalities) and apply them to everybody's device. In the end we have to stress that this is a visual approximation - it is not suitable for making decisions about ball visibility, or to evaluate products. We have worked with cricketing organisations in the past to help them develop an understanding of the conditions of play, and would be happy to hear from any organisation who is interested to work together to conduct research and make informed decisions - please use the contact form.

Why isn't the grass green?

The visualiser takes measurements of the spectral reflectance of a surface taken from within each ground. Then it applies a illumination spectrum (lighting) also based on measurements from within the grounds. Finally it calculates a representative RGB value for the resulting spectrum which is what tells you device what colour to make the ball or background. One reason that things might not appear in their expected colour is that the RGB colour is representing both the lighting and the surface colour. We were lucky to have fairly sunny days when collecting our measurements, so in the daytime models the grass is under direct sunlight, which is yellowish. Therefore it may render more yellow in the visualiser. A second reason is that our displays all differ. An RGB which is presented on one screen can be very different to the same RGB sent to another screen. The visualiser uses sRGB to convert the measurements to RGB values. This is an industry standard which many devices aim for, and which tends to produce fairly acceptable colour matches on uncalibrated displays. If your display is a perfect sRGB display (this is not easy to find out) then you would find that the colour is a pretty good match... This brings us to the final reason - although we call it “green” grass is, actually, quite a yellowish green. This is particularly so for grass which grows in the open (compared to in shady areas).

Why am I seeing a warning about the accuracy of the colours?

The visualiser aims to represent the luminance contrast between the ball and background for a given scenario. To do this we use real data - measurements of cricket balls, playing fields, skies, and the lighting in grounds. Then we convert these into colours which can be represented on the screen (RGB values). Representing real world contrast on a screen is difficult as digital displays have a much narrower dynamic range than the real world. When this warning pops up (currently on <20% of possible combinations) it means that standard displays cannot produce bright or dark enough colours to represent the contrast which is available in the real world. Usually this is because the ball is either very bright or very dark (i.e. high contrast). Scenarios where the ball and background are more similar to one another (lower contrast) are generally unaffected. This isn't anything to do with your display device, it is a challenge of trying to recreate real world colours on a screen. The warning will disappear for combinations of ball and background which do not have this problem.

How old is an “old” ball?

The modelling in this visualiser is based on the ball measurements we report in our 2024 paper (http://doi.org/10.1016/j.jsams.2024.02.004). We obtained examples of red, pink and white Dukes balls which has been used in professional matches for between 40 and 60 overs. We are working on obtaining used balls over a greater range of ages and for other brands. If you think you can help us with this please get in touch using our “Contact” page.

Why is the ball black/white?

This occurs if the ball is at very high contrast (i.e. much darker or much brighter) against the background. Each time the visualiser generates the colours to show you a scenario it has to balance the available contrast between the background and foreground (ball). To do this and make the background stable we set the brightness of the background to a standard level, which means that for some balls the best we can do is show a very bright (white) or dark (black) ball to indicate the strength of the contrast, but at the expense of accurate colour.

Why do you have the greyscale toggle?

Detecting motion relies primarily on a pathway which is more-or-less insensitive to colour. This means that although there may be a colour difference between a ball and background, if there isn't a luminance difference the ball may be very hard to spot when in motion. The greyscale toggle provides an approximation of what the motion pathway “sees” for your chosen scenario.

I have a suggestion for an improvement!

Great! Please get in touch using our Contact form.