For practical image compression systems, handling images divided into independent tiles in the pixel domain is important. However, tiling introduces artifacts when transform coefficients are quantized The paper presents a "detiling" solution applicable to wavelet transform coefficients. The solution, called projection onto scaling functions, eliminates the blocking artifacts by computing approximations that match the smoothness of the compressed image inside a tile. This solution is applicable to any wavelet filter - extending previous work that applied only to a limited class of wavelet filters - and specifically targets decoding of JPEG2000 compressed images.