You probably need to research on memory mapped files so you can process huge files easily.https://docs.microsoft.com/en-gb/windows/desktop/Memory/file-mapping
It is not always possible to get a solid chunk of memory (2 Gb) on the system with 8 Gb.
circular,i dont need 32bits per pixel. i only care about the resolution of the picture. photoshop can open this picture,but my program cant. Iif there is a control which can load this big resolution picture?
i only care about the resolution of the picture.