An object of the invention is to display an image giving a feeling close to the feeling of a knitted fabric actually knitted with a knitting yarn. Linear knitting yarn image data 1 is divided into a plurality of meshes 2. The mesh 2 is made to match a transformed mesh 3 transformed along the shape of a knitting stitch loop 4. The knitting yarn image data 1 is subjected to an image drawing processing by a mesh transforming technique to create the image of the knitting stitch loop 4. A lower section 4a and an upper section 4b are defined in a portion where the knitting stitch loops 4 are overlapped, the portion where the knitting stitch loops are overlapped is synthesized as a knitted fabric 6, and displayed. Fluffiness or the like is also reproduced, and consequently the feeling like that of an actual knitted fabric can be given.