We shoot a specially designed chart in carefully controlled conditions and the resulting images are analysed using DXO Analyzer software to generate the data to produce the graphs below.
A high signal to noise ratio (SNR) indicates a cleaner and better quality image.
For more more details on how to interpret our test data, check out our full explanation of our noise and dynamic range tests.
JPEG signal to noise ratio
Here, JPEG files from the Sony TX20 are very similar to those from the Canon D20 and Panasonic FT4, achieving a slightly higher signal to noise ratio at every sensitivity, but reacting in the same sort of way to changes in ISO settings. The Olympus TG-1's images show a higher signal to noise ratio than the Sony's at every ISO aside from ISO 800 and ISO 3200.
JPEG dynamic range
The picture here is different, and more diverse, with the Sony TX20's dynamic range results most closly resembling the Olympus TG-1 and Panasonic FT4's up to ISO 800, before they then move to almost match those of the Canon D20 at higher ISOs.