Determining JPEG Image Standard Quality Factor from the Quantization Tables

Rémi Cogranne (1)

1 LM2S - Laboratoire Modélisation et Sûreté des Systèmes

Identifying the quality factor of JPEG images is very useful for applications in digital image forensics. Though several command-line tools exist and are used in widely used software such as \emph{GIMP} (GNU Image Manipulation Program), the well-known image editing software, or the \emph{ImageMagick} suite, we have found that those may provide inaccurate or even wrong results. This paper presents a simple method for determining the exact quality factor of a JPEG image from its quantization tables. The method is presented briefly and a sample program, written in Unix/Linux Shell bash language is provided.

Domaines: Traitement du signal et de l'image [eess.SP]

Rémi Cogranne. Determining JPEG Image Standard Quality Factor from the Quantization Tables. 2018. ⟨hal-03321113⟩