A photographer takes pictures at the media preview of The Moment for Ink joint exhibition held at Chinese Culture Center of San Francisco, the United States, on Feb. 22, 2013. The Moment for Ink joint exhibition featuring 150 ink paintings by 50 artists from China, the United States, Germany and Nigeria will be opened on Feb. 23 at four venues in San Francisco. [Xinhua/Liu Yilin]

A visitor views the works of American artist Jonathan Wallraven at the media preview of The Moment for Ink joint exhibition held at Chinese Culture Center of San Francisco, the United States, on Feb. 22, 2013. The Moment for Ink joint exhibition featuring 150 ink paintings by 50 artists from China, the United States, Germany and Nigeria will be opened on Feb. 23 at four venues in San Francisco. [Xinhua/Liu Yilin]

People view paintings at the media preview of The Moment for Ink joint exhibition held at Chinese Culture Center of San Francisco, the United States, on Feb. 22, 2013. The Moment for Ink joint exhibition featuring 150 ink paintings by 50 artists from China, the United States, Germany and Nigeria will be opened on Feb. 23 at four venues in San Francisco. [Xinhua/Liu Yilin]

A cameraman shoots at the media preview of The Moment for Ink joint exhibition held at San Francisco State University, the United States, on Feb. 22, 2013. The Moment for Ink joint exhibition featuring 150 ink paintings by 50 artists from China, the United States, Germany and Nigeria will be opened on Feb. 23 at four venues in San Francisco. [Xinhua/Liu Yilin]