1. A computer implemented method for detecting and quantifying blockiness in a video file, the video file comprising one or more frames, the method comprising: segmenting one or more of the frames into one or more blocks; comparing one or more intensity gradients associated with the one or more blocks with one or more threshold values, wherein the one or more threshold values signify pre-defined intensity variation values; based on the comparison, determining one or more intensity variation parameters for the one or more blocks; computing a blockiness index for the one or more blocks, wherein the blockiness index is calculated using the one or more intensity variation parameters of the corresponding one or more blocks; and determining a level of blockiness for the one or more frames based on the blockiness index of the corresponding one or more blocks.