The invention discloses a method and device for image filtering in the field of communication technologies, the method including: acquiring image data of a pixel dot of a current row to be filtered and a corresponding pixel dot of at least one adjacent row; obtaining contrast information containing a transparency value, of the pixel dot of the current row and the pixel dot of the adjacent row respectively by resolving the image data of the pixel dot of the current row and the pixel dot of the adjacent row; generating a filter coefficient according to the transparency value of the pixel dot of the current row and the transparency value of the corresponding pixel dot of the adjacent row; and performing filtering on the pixel dot of the current row with the filter coefficient. The embodiments of the invention effectively avoid image flickering due to a difference between contrasts by adopting the method of at-least-two-row vertical filtering, and by generating the filter coefficients according to the transparencies in filtering.