It is possible to improve an image quality of an ultrasonographic device and improve visibility of a tissue structure and a lesion. According to a noise amount estimated for each of at least two resolution levels and reliability of the noise amount estimation, a corrected noise amount is calculated. An intensity conversion is performed on a decomposition coefficient obtained by a multi-resolution decomposition process using the corrected noise amount. Moreover, by performing intensity conversion of the respective decomposition coefficients according to a plurality of decomposition coefficients, it is possible to generate a high-quality image. Furthermore, by switching processing parameters in accordance with the imaging condition, the image type, and the imaging object, it is possible to simultaneously realize the processing time and the image quality appropriate for the purpose.
