Check base64 string(image) type using C#

hi,

Actually my application i have the upload image functionality there i have passed one parameter(base64string) to my controller. here i want to check the base64string type . i tried one way but that was wrong if anybodys know please tell me that answer .

i need to change this line . how to check the type inside that string ,

 string x = base64image.Replace("data:image/png|tiff|jpg|gif;base64,", "");

this is my code,

public bool LoadImage([FromBody]string base64image)

{

string x = base64image.Replace("data:image/png;base64,", "");

byte[] data = System.Convert.FromBase64String(x);

MemoryStream ms = new MemoryStream(data);

Image img = Image.FromStream(ms);

return false;

}