Lena's story

jamesmith

看到白菜哥的贴后想起这张照片, 读过image processing的应该见过~~


The original (uncompressed) Lena image.


The Lena image compressed to 1.0 bit per pixel using NSI.


A scaled plot of the difference between the original image data and the 1.0 bpp NSI compressed Lena image. Magnitude zero errors are represented by neutral gray.


The white pixels indicate the position of sample points taken by NSI to compress the Lena image to 1.0 bpp.


A plot of the intensity data of line 266 of the original (uncompressed) Lena image.


A plot of the intensity data of line 266 of the 1.0 bpp NSI compressed Lena image.


Lena original in color


Lena full picture


Lena unpublished picture


The Lenna (or Lena) picture is one of the most widely used standard test images used for compression algorithms.

Alexander Sawchuk estimates that it was in June or July of 1973 when he, then an assistant professor of electrical engineering at the USC Signal and Image Processing Institute (SIPI), along with a graduate student and the SIPI lab manager, was hurriedly searching the lab for a good image to scan for a colleague's conference paper. They had tired of their stock of usual test images, dull stuff dating back to television standards work in the early 1960s. They wanted something glossy to ensure good output dynamic range, and they wanted a human face. Just then, somebody happened to walk in with a recent issue of Playboy.
The engineers tore away the top third of the centerfold so they could wrap it around the drum of their Muirhead wirephoto scanner, which they had outfitted with analog-to-digital converters (one each for the red, green, and blue channels) and a Hewlett Packard 2100 minicomputer. The Muirhead had a fixed resolution of 100 lines per inch and the engineers wanted a 512 x 512 image, so they limited the scan to the top 5.12 inches of the picture, effectively cropping it at the subject's shoulders.

The original image is still available as part of the USC SIPI Image Database in their "miscellaneous" collection.

Over the years there has been quite a bit of controversy over the use of this image. Some people proposed banning the use of this image because of its source. Also, Playboy threatened to prosecute the unauthorized use of the image. Check out an editorial by the editor of SPIE journal Optical Engineering. Check out a note by the former editor-in-chief of the IEEE Transactions on Image Processing. According to Wired Magazine, Playboy has eased up in its pursuit of the copyright violators of this image.

Another interesting piece of trivia is that Lenna's issue (November 1972) was Playboy's best selling issue ever and sold 7,161,561 copies.