English: Demonstration of interlace and so-called "interline twitter", based on part of an RCA Indian Head Test Card ca. 1940. From left to right: progressive, interlace animation, and reconstructed using "bob" (interpolation per field) algorithm. Top row: original full-resolution image; bottom row: vertically blurred using [1 4 6 4 1]/16 kernel. Progressive images are darkened somewhat to match the effective brightness of the interlaced images.
This is a retouched picture, which means that it has been digitally altered from its original version. Modifications: Interlaced, animated, retouched, and blurred. The original can be viewed here: RCA Indian Head test pattern.JPG: . Modifications made by Damian Yerrick.
Note that it may still be copyrighted in jurisdictions that do not apply the rule of the shorter term for US works (depending on the date of the author's death), such as Canada (50 p.m.a.), Mainland China (50 p.m.a., not Hong Kong or Macao), Germany (70 p.m.a.), Mexico (100 p.m.a.), Switzerland (70 p.m.a.), and other countries with individual treaties.
{{Information |Description={{en|Demonstration of interlace and so-called "interline twitter", based on part of an RCA Indian Head Test Card ca. 1940. From left to right: progressive, interlace animation, and reconstructed using "bob" (interpolation per fi