1. A method for improving a speed of rasterizing transparent images, comprising: determining, from P graphic entity objects on a transparent page, M transparent images and N nontransparent images, each of the N nontransparent images including an intersecting area with one of the M transparent images, P being an integer larger than 0, M being an integer larger than 0 and smaller than or equal to P, N being an integer larger than or equal to 0 and smaller than P, and P=M+N; determining a page-level transparent area and a page-level de-transparentizing area of the P graphic entity objects, contributions of the transparent images and the nontransparent images to the page-level transparent area and the page-level de-transparentizing area being calculated using different methods; and assembling the M transparent images according to the page-level transparent area and the page-level de-transparentizing area.