Abstract: An oil treating agent of W/O emulsion, wherein an aqueous dispersed phase is dispersed in an oily continuous phase, and wherein the dispersed phase is an alkaline mixture solution obtained by mixing water, a solution comprising water and an alcohol, or a water-free alcohol solution with an alkali hydroxide e.g. sodium hydroxide or with a metal alkoxide e.g. sodium alkoxide and the continuous phase comprises a liquid incompatible with the dispersed phase.

Abstract: An area filling method develops a binary graphic which has a contour described by direction codes of black picture elements into a raster graphic and fills an inside portion of the raster graphic by a raster scan. The area filling method prepares a start position table which defines area filling start positions for each of the direction codes. Then, a region of the binary graphic is scanned in a predetermined direction starting from an area filling start position, which region includes a black picture element which constitutes the contour. Each scanned white picture elements within the region is marked as a first type picture element and a black picture element which is scanned first within the region is marked as a second type picture element. An area filling start position which corresponds to a direction code of the second type picture element is obtained by referring to the start position table, and the region is successively moved with respect to all black picture elements which constitute the contour.