To directly recognize and retrieve a specific pattern from compressed moving picture data through the use of the parameter of maximum likelihood with respect to a symbol string by extracting a DCT coefficient from image data and transforming its feature vector string to the symbol string.

One frame of image data is divided by MPEG data 1 to obtain the DCT(discrete cosine transformation) coefficient of each unit. Next, a feature extraction part 2 fetches the frame feature vector of a low frequency component. Similarly, the feature vector string of a series of moving picture data is fetched and recorded in a memory for storing feature 3. Next, a quantization part 4 vector-quantizes it and records the symbol string in a symbol storing memory 5. A model parameter estimating part 6 estimates the parameter of such a state transition model as generates this symbol string and records it in a state transmission model storing memory for recognition 7. A likelihood calculating part 8 estimates the parameter of the model of high likelihood for each category of a recognizing object and stores it in a memory for a recognizing result 9. Thereby the specific moving picture pattern is recognized and retrieved from compressed moving picture data.