If you notice most popular image processing applications, we could see a beautiful and sexy face of a girl as the standard test image. I was thinking, why most of the applications using the same image. I finally I managed to find her name from a sample file. It was Lena (or Lenna). Googling on her name returned a proper link to Wikipedia.

The image is originally cropped (:D) from Playboy Magazine centerfold picture. Swedish model Lena Söderberg paused naked for the 1972 November issue of Playboy magazine. It’s one of the most widely used images for testing image processing algorithms such as compression, denoising etc…

According to David C. Munson, editor-in-chief, January 1996 IEEE Transactions on Image Processing the wide popularity of image is because of two reasons.

First, the image contains a nice mixture of detail, flat regions, shading, and texture that do a good job of testing various image processing algorithms. It is a good test image! Second, the Lena image is a picture of an attractive woman. It is not surprising that the (mostly male) image processing research community gravitated toward an image that they found attractive    

Wikipedia also cited the controversy regarding this particular image.

The use of the image has produced some controversy, with some people concerned about Playboy magazine as the source of the image, and with the image being copyrighted.

When the IS&T wanted to invite Lena to their meeting,[5]

“Playboy helped track down the Swedish native in Stockholm, where she helps handicapped people work on (non-networked) computers. Although Playboy is notorious for cracking down on illegal uses of its images, it has decided to overlook the widespread distribution of this particular centerfold.

Says Eileen Kent, VP of new media at Playboy: “We decided we should exploit this, because it is a phenomenon.”"

Coincidentally, Playboy states the issue was its best-selling ever, having sold 7,161,561 copies as of May 2006.

OK that’s the story behind Lena!!!