Can anyone tell, From where this Digest value Coming from?

Structure of XML:

(CanonicalizationMethod)?
(SignatureMethod)

(Transforms)?
(DigestMethod)
(DigestValue)
)+

(SignatureValue)
(KeyInfo)?
(Object)*

DigestValue:
DigestValue contains the Base64 encoded result of applying the hash algorithm to the transformed resource(s) defined in the Reference element attributes.

Validation:
Reference Validation: Each Reference's digest is verified by retrieving the corresponding resource and applying any transforms and then the specified digest method to it. The result is compared to the recorded DigestValue; if they do not match, validation fails.