In case you wanted to test the automatic vectorization feature on clker, one possible way is to capture your own images using your digital camera and that’s a very easy process. However, a quick and easier solution would be to use a readily available public domain image. Images that are on the internet by default are copyright protected so you can’t grab an image from anywhere and “think” that it is public domain just because its owner did not say it is copyright protected. Some good sources of public domain images are:
1. My best source is wikimedia.org. They have around 47000 images that are public domain in the US in this category ( http://commons.wikimedia.org/wiki/Category:PD_US ). Most of those images comply with the upload policy of clker.com , some don’t.
2. The library of congress ( http://www.loc.gov/library/libarch-digital.html ). You have to be careful with that one and read the rights of every collection. Many images are dated before 1923, and most of those are public domain as long as they were actually published before 1923 ( you need to read the date on the description as well ).
3. US Government websites:
a. National cancer institue ( http://visualsonline.cancer.gov/ ): Some images here are in public domain, others are not so you need to read the rights under every image carefully.
b. US military websites: http://www.armymedicine.army.mil/news/photos/photos-new.cfm http://search.ahp.us.army.mil/search/images/?search= http://www.carlisle.army.mil/AHEC/mediagallery/photoGalleryList.cfm and lots of others. On google search for “site:.mil photo gallery” and you will get a lot of hits.
Generally for all gov and mil websites, if the picture is taken by a government photographer it is in public domain. However, if the image contains people currently alive, those people can request that their image be deleted. If the picture contains living or dead actors, then either them or their heirs can do the same. So if you are testing, keep your choices confined to photos of things and animals, and actually there are tons of those.
I also recommend renaming the files before uploading them with a more relevant title. Images with names SDC002123.jpg gives clker no clues about what the image contains, and does not help us to automatically classify the image. However, if the image is named giraffe_in_zoo.jpg that will actually help clker more to categorize the image.
Have fun vectorizing on clker.