A spokeswoman for London's Tate Modern gallery said the gallery was "pleased" with today's court decision.
Wlodzimierz Umaniec has been jailed for two years for defacing a painting by artist Mark Rothko.
Gregor McKinley, prosecuting, said:
Mr McKinley said work to restore the painting will take about 20 months and cost "something around £200,000."
Gareth Morgan, defending, said it would take a "significant amount of effort, expert effort at that" to restore the "important, valuable piece of art".
Paintings by Russian-born artist Rothko often fetch tens of millions of pounds.
Judge Roger Chapple, at Inner London Crown Court, told Umaniec: "Your actions on the 7th of October of this year were entirely deliberate, planned and intentional."
He said it was "abundantly clear" that Umaniec was "plainly an intelligent man" and told the court he had described Rothko as a "great painter" in a letter he had written to him.
The judge also said the incident had led to galleries reviewing security arrangements at a cost to themselves and the taxpayer.
"The effects of such security reviews is to distance the public from the works of art they come to enjoy," he said.
A man has been jailed for two years for defacing a painting by artist Mark Rothko.
Wlodzimierz Umaniec, 26, also known as Vladimir Umanets, defaced the mural, worth in the region of £5 million to £9 million, at London's Tate Modern gallery on 7th October this year.
Umaniec, a Polish national living in Worthing, West Sussex, admitted criminal damage to the value of in excess of £5,000 - but estimates suggest the restoration of the painting will cost around £200,000.
A man accused of criminal damage after a Mark Rothko painting was defaced at London's Tate Modern gallery has been remanded in custody until October 16
Wlodzimierz Umaniec, 26, also known as Vladimir Umanets, appeared at Camberwell Green Magistrates' Court via video-link today accused of damaging the famous painting, worth in the region of £50 million.
The court heard that Umaniec, a Polish national, will deny the charges.
He spoke only to confirm his personal details and provided a friend's address.
A man was tonight charged with criminal damage after a Mark Rothko painting was defaced at London's Tate Modern gallery.
Wlodzimierz Umaniec, 26, also known as Vladimir Umanets, was charged with one count of criminal damage in excess of £5,000 and will appear before magistrates at Camberwell Green tomorrow morning.
The Polish national, of no fixed abode, was arrested yesterday after the mural was vandalised on Sunday.
A man has been arrested in connection with the criminal damage to a Mark Rothko painting at Tate Modern, the Metropolitan Police Service has announced.
The 26-year-old man, who has not been named, was arrested about 9pm this evening by Sussex Police - on behalf of the MPS - at an address in Worthing.
The suspect is currently in custody at a Sussex police station and will be escorted overnight to a police station in London by officers from the MPS, police added.
Art expert Amy Griffin says the Tate Modern should be equipped to restore the mural back to its original state. But how hard that will be depends on whether paint or marker pen has been used.
Speaking to ITV News, Vladimir Umanets, insisted he was not a vandal and felt he had been "completely attacked" over the writing daubed on the Rothko mural. He defended "Yellowism" which he founded, and said the police hadn't contacted him - yet.