You must have noticed that many devices have the same camera sensor for example IMX 363 by Samsung.
But when you compare the images from the two phones you might see there is a significant difference between the two images.
WHY THE DIFFERENCE?
There are literally many factors to be considered and it changes from device to device.
Every device has its own proprietary camera app. Resulting in different image processing. Hence different White Balance and Noise in the image.
Different Lense. The lens is not a part of the Camera Sensor. While a cheap phone will generally use low quality generic lenses while a good brand will use good quality lenses.
It’s not only the sensor that takes part in the picture. Choosing a proper lense is up to the Mobile manufacturer and not the sensor manufacturer.
A camera unit is not only the sensor but also the ADC( Analog to digital converter) and DSP (Digital Signalling Processor) with the algorithms.
Basically the sensor is just a converter which converts the incoming Light to an electric signal.
After that the electric signal is interpreted by the ADC according to the look up table which is a curve as sensors are not perfectly linear. and there are spikes and dents in the electric signal which are needed to be corrected so as to produce a picture well within the expectations of a consumer’s range.
After that the DSP is used to De-Noising the image as well as for some image enhancement.
SO BASICALLY THESE COMPONENTS DECIDE THE PICTURE QUALITY AND ONLY THING SAME IN THESE MOBILE DEVICE IS THE SENSORS AND NOT ADC, DSP AND THE ALGORITHM. Hence producing different images.