I needed a test image to be used in some examples of image processing. In books and articles, Lenna is commonly used, but I can't use it on Commons because it is not in the public domain.
I took a look at the featured pictures, and I have decided to use Image:Lichtenstein.jpg because it has several details (higher frequencies) in the bottom left and almost no details (lower frequencies) in the top right, plus sharp edges (between the castle and the sky). It's not as pretty as Lenna, but it's a good compromise! Moreover, it was not taken with a digital camera, so it does not show the typical artifacts due to Bayer pattern.
Using GIMP, I have cropped the original image in order to have a squared picture, then I have downscaled it to 512x512 pixels using bi-cubic interpolation: this way the smaller image should have all the frequencies and the artifacts of the original JPEG compression should be negligible. I saved it in a lossless PNG to save the higher frequencies that could be removed by a JPEG compression.
Those are the pictures I have created starting from this one:
Es, šī darba autortiesību īpašnieks, publicēju to saskaņā ar šo licenci:
Ir dota atļauja kopēt, izplatīt un/vai pārveidot šo dokumentu saskaņā ar GNU brīvās dokumentācijas licences, versijas 1.2 vai jebkuras vēlākas versijas, ko publiskojis Brīvās programmatūras fonds nosacījumiem; bez nemainīgajām sadaļā, priekšējā un aizmugurēja'vāka tekstiem. Licences kopija ir iekļauta sadaļā ar nosaukumu GNU brīvās dokumentācijas licence.http://www.gnu.org/copyleft/fdl.htmlGFDLGNU Free Documentation Licensetruetrue
atsaucoties – Tev ir jānorāda autors, saite uz licenci un to, vai veiktas kādas izmaiņas. To var darīt jebkādā saprātīgā veidā, bet ne tādā, kas norādītu, ka licencētājs atbalsta tevi vai veidu, kā tu izmanto šo darbu.
nemainot licenci – Ja tu miksē, pārveido vai izmanto materiālu, tev savs devums jāpublicē ar to pašu vai saderīgu licenci kā oriģināls.
This licensing tag was added to this file as part of the GFDL licensing update.http://creativecommons.org/licenses/by-sa/3.0/CC BY-SA 3.0Creative Commons Attribution-Share Alike 3.0truetrue
Captions
Pievieno vienas rindiņas aprakstu, ko šis fails attēlo
{{Information |Description=I needed a test image to be used in some examples of image processing. In books Lenna is commonly used, but I can't on Commons because it is not in the public domain. I took a look at the featured pictures, and I ha