Saves D3D texture to memory in one of formats supported by Imaging.

function SaveD3DTextureToMemory(const Ext: string; 
                                Data: Pointer; 
                                var Size: LongInt; 
                                const Texture: IDirect3DTexture9): Boolean;

ImagingDirect3D9 (at line 129)

Saves all present mipmap levels.