Lesson plan
Xv (software)
xv is a shareware program written by John Bradley to display and modify digital images under the X Window System. While popular in the early 1990s ("XV is widely considered to be the preeminent image viewer for the X Window System" ), no official releases have been made since December 1994. Bradley was unable to negotiate the LZW patent license necessary for encoding the then-popular GIF format. The patent has now expired, so this legal constraint is no longer relevant. Until at least 2000, Bradley collected third-party updates to xv, for example, support for the PNG image format. These were published as source code patches only. xv can be run from the command line and offers a graphical interface. xv can be used also for image manipulation (cropping or stretching of images and other effects), supports various image file formats (including among others Sun Raster, or Targa) and allows export to PostScript. It distinguishes itself from many other bitmap viewing and editing programs with a very efficient interface in which the user edits just the parameters of a fixed pipeline of processing steps, rather than modifying the bitmap directly in each operation. As a result, the user can easily undo operations (such as cropping, color modifications, filtering) out of order, rather than only being able to undo the respective last operation.…
Article summary
xv is a shareware program written by John Bradley to display and modify digital images under the X Window System. While popular in the early 1990s ("XV is widely considered to be the preeminent image viewer for the X Window System" ), no official releases have been made since December 1994. Bradley was unable to negotiate the LZW patent license necessary for encoding the then-popular GIF format. The patent has now expired, so this legal constraint is no longer relevant. Until at least 2000, Bradley collected third-party updates to xv, for example, support for the PNG image format. These were published as source code patches only. xv can be run from the command line and offers a graphical interface. xv can be used also for image manipulation (cropping or stretching of images and other effects), supports various image file formats (including among others Sun Raster, or Targa) and allows export to PostScript. It distinguishes itself from many other bitmap viewing and editing programs with a very efficient interface in which the user edits just the parameters of a fixed pipeline of processing steps, rather than modifying the bitmap directly in each operation. As a result, the user can easily undo operations (such as cropping, color modifications, filtering) out of order, rather than only being able to undo the respective last operation.…
Key claims
No claims recorded.
Discussion questions
- Summarise the article in your own words. Which single claim would you verify first, and why?
- Which claim in this article is most likely to be revised as the sources update? How would you check its current status?
- If two sources disagreed about one of these facts, what would you need in order to trust one over the other?
Bibliography
No sources recorded.
Key claims and bibliography are generated from the same tracked claims and sources as the article page.