1. A computer-implemented method comprising: receiving, at a computer server system from a mobile device, a first training image taken by a camera module of the mobile device and an image-context attribute describing a context associated with the first training image, wherein the image-context attribute is separate from the first training image; adding, by the computer server system, the first training image into a sub-group of training images in accordance with a similarity based, at least in part, on the image-context attribute; in response to determining that a training set of images including the sub-group provides a threshold amount of data samples to compute a calibration parameter model, computing, by the computer server system, the calibration parameter model based, at least in part, on the sub-group of training images utilizing dimension reduction statistical analysis, wherein the calibration parameter model configures at least an image adjustment process corresponding to the image-context attribute and wherein the image adjustment process is configured to define how to post-process a raw photograph after being captured by the camera module; and causing, by the computer server system, an image processor to calibrate the raw photograph of the camera module by providing the calibration parameter model to the image processor.