This method is a special version of IM_HITTEST for images that support IM_DRAWFRAME. It asks an image if a point would be inside it if the image was confined (scaled, clipped, etc.) to a rectangular bounds. The return value for this method is not explicitly defined. This method uses a custom message structure: struct impHitTest { ULONG MethodID; /* IM_HITFRAME */ struct { WORD X; /* Coordinates of point to test for hit */ WORD Y; } imp_Point; struct { WORD Width; /* scale, clip, restrict, etc. to these bounds */ WORD Height; } imp_Dimensions; }; The imageclass dispatcher treats IM_HITFRAME just like IM_HITTEST, ignoring the restricting dimensions.