IS there Python function instance of Save Current Rendered Image in Solaris? I want to quickly save Images to disk by script.

Maybe you could use flipbook

cur_desktop = hou.ui.curDesktop()

filename = "D:/image.png"

frame = hou.frame()

scene = cur_desktop.paneTabOfType(hou.paneTabType.SceneViewer)
flip_options = scene.flipbookSettings().stash()
flip_options.frameRange( (frame, frame) )
flip_options.resolution((1024,1024))
flip_options.output(filename)
scene.flipbook(scene.curViewport(), flip_options)

also check
FlipbookSettings [www.sidefx.com]