wrote:..i am tired of searching it in net..
I find it impossible to believe that you looked at all. In VB.NET, you can use the GetPixel method to get RGB values. That it's a JPG is irrelevant, excepting that your image will be degraded, an area of pure white in a bmp will turn to many shades of white in a jpg. It is lossy.
If you use a C# dll, you can use the direct pixel access methods illustrated in my images processing articles here on Code Project.