请教如何编程获取显卡的gamma table信息？

[mizhael]

需要从显卡读取framebuffer value -> DAC value 的gamma转换表。我的ati显卡的设置中有一项是可以设置和读取gamma table信息的。台湾的powerstrip也能如此。http://entechtaiwan.net/util/ps.shtm
现在需要编程读取该gamma table信息。有大虾知道如何对显卡读取吗？

GetDeviceGammaRamp and SetDeviceGammaRamp 不行。我从网上下载了几个quickgamma等程序：但是他们设置的gamma不改变屏幕的显示亮暗。他们读取的gamma不反映ati设置的改变。因此这两个WIN32 API不行。(Windows XP Pro环境）

The tutorial from ATI says that these two
functions, along with their counterparts in DirectX, only work when the full
screen application gains control of the whoel screen, such as 3D games.

但是我需要能够立即改变整个屏幕的gamma设置，就如ati的setting和台湾的powerstrip一样。有大侠知道应该怎么做吗？

非常感谢。

[spbabyba]

GetDeviceGammaRamp and SetDeviceGammaRamp
这两个应该可以我用过

[mizhael]

还是不行。
下载了关于上面两个函数的例程，还是不行，在我的电脑上，屏幕毫无变化。
如果Direct3D里面的设置gamma table是可以的，但那些函数只对Direct 3D full screen mode可以。对屏幕上的其它窗口无效。

需要读取和设置显卡的gamma table,和white-point的值。
就像台湾的powerstrip作的那样。
http://entechtaiwan.net/util/ps.shtm

但是怎么做呢？

好像最多只能100分。有给更高分的方法吗？

如有解法，愿付报酬。。。

[mizhael]

以下两种可能的做法应该怎么进行？
1。A GDI filter is a kernel mode display driver that
loads the real display driver. It follows the rules of
a kernel mode display driver.It loads the real display driver in its
DrvEnableDriver routine which is the standard exported
function driver. EngLoadImage/EngFindImageProcAddress in DDK doc.
Since display driver is coupled with a video miniport
driver, one also needs to modify the miniport's INF to
load the GDI filter instead of the real display driver. See video miniport INF file section in DDK DOC.

2。"better approach might be to write a wrapper driver -- a driver that
has all the entry points of a video or printer driver. In your
wrapper driver, your Enable() will call the real driver's Enable(),
which when called the first (or is it the 2nd?) time, returns GDIINFO.
You then modify the GDIINFO returned by the real driver's Enable() and
return from your Enable()."