The upsample option increases the number of pixels in the input image by the specified factor, thereby increasing the size of the resulting output image. You can specify any whole number value as long as the result does not exceed the maximum image size allowed. For example, a bitonal image that is 2,000 x 1,000 pixels can be upsampled using values 1 through 16 (16 * 2,000 = 32,000, the maximum size allowed for bitonal images). A color image that is 2,000 x 1,000 pixels can be upsampled using values 1 though 13 (13 * 2,000 = 26,000, which does not exceed the maximum 27,500 size allowed for color images).
Supporting commands:
documenttodjvu, djvudecode