The invention provides a soot collection quantity measuring device for a diesel particulate filter. Each cylinder includes a respective piston reciprocally movable between respective top and bottom positions along a cylinder longitudinal axis. The conveying mechanism is arranged in the sheet conveying path to convey a sheet. For trilinear filtering, texels in a first LOD are retrieved for a number of pixels during a first clock cycle, during a second clock cycle, texels in a second LOD are retrieved.