Detection method for HEVC prediction mode steganography

The invention discloses a detection method for HEVC prediction mode steganography. The quantity and occupation proportions of prediction units of different sizes in I frames of an HEVC compressed video sequence, an HEVC recompressed video sequence, a secret carrying video sequence and an HEVC recompressed secret carrying video sequence; the change rates of the quantity and occupation proportions of the prediction units of different sizes in the HEVC compressed video sequence and the HEVC recompressed video sequence are calculated; the change rates of the quantity and occupation proportions of the prediction units of different sizes in the secret carrying video sequence and the HEVC recompressed secret carrying video sequence are calculated; feature vectors of the HEVC compressed video sequence and the secret carrying video sequence are formed; a training template is obtained by employing an SVM classifier; an HEVC video is tested; feature vectors are obtained by employing the same method; the feature vectors are input in the training template, thereby obtaining detection results. The method has the advantages that the detection effect on various steganographic algorithms of modifying prediction modes is very good; the computing complexity is relatively low; and the detection effect on the videos with different resolutions under different quantization parameters is relatively good.