What I see is a rather artistic photo. It surely contains nudity, but it's nonetheless a work of art. If nudity is porn, then Picasso was a pornographer:
It's not a question of being prudes. The definition of pornography is "sexually explicit pictures, writing or other material whose primary purpose is to cause sexual arousal". I think we can all agree that Playboy fits that definition. Hence, the full Lena picture is porn by definition. Secondly, labeling it as porn can only be considered prude behaviour if you're offended by porn. Personally, I do not find porn offensive. Do you? Lastly, something can be pornography and still be artistic. I think the real prudes are those who think that there can be no overlap between art and porn.
>The definition of pornography is "sexually explicit pictures, writing or other material whose primary purpose is to cause sexual arousal"
Which means image processing algorithms to detect "pornography" are doomed to failure, if they are tasked with determining the "purpose" of the image. (Maybe we'll get there someday, but we're many decades away from anything like that, I think.)
What they're actually doing, it looks to me, is making nudity detectors -- which quite correctly flag artistic nudes. The article fails to make this distinction at all.
"Hence, the full Lena picture is porn by definition."
The author wrote:
"One cannot do research in image processing without an encounter with Lena (pronounced Lenna). The image of the woman with a feathered hat has become the de-facto test image for many algorithms, and appears in thousands of articles and conference papers. And it is porn."
So, the author is claiming that the image that is showed in all those scientific papers is porn. And that image is not the full Lena image. Thus, according to your definition, the author seems to get aroused by women's faces and feathered hats. I rest my case...
The definition merely states that material is pornographic if its primary purpose is to appeal to the erotic instincts, without mentioning that it actually has to succeed. It can be easily shown that this is also the commonly understood definition by making the simple observation that most people would agree that granny porn is still porn by virtue of the fact that it was created with the intent to arouse, even if neither you nor I are, in fact, aroused by it. In other words, you have no case, even if I were referring to that, which I wasn't. (Incidentally, that definition came from a dictionary, and is not "my definition", just so we're clear.) Now that we've established that the author need not have been aroused by a picture for it to be considered porn, we can, I suppose, argue forever and a day about whether the author was referring to the full Lena picture or not when he said it was porn, but I won't do that. I interpret it as the author referring to Playboy, the source of the picture, which is by definition porn, but if you interpret it to mean that the author is saying that pictures of "women's faces and feathered hats" are porn, well, then we must agree to disagree, even if I think that is a weird position to take :)
Now, to get down to cases, in the comment I was actually replying to, what you said was this:
What I see is a rather artistic photo. It surely contains nudity, but it's nonetheless a work of art.
Since Lena as used in CS does not contain nudity, you must have been referring to the original Playboy picture, which I doubt you can honestly argue was not created with the intention of appealing to the erotic instincts.
I agree with you. I don't want to keep discussing what is and what is not entitled to be labeled as porn, though. On the other hand, we have the word "nudity" which is more specific than the word "porn". The full Lena image qualifies as nudity for sure. Moreover, there can be porn without nudity. Whatever...
http://www.lenna.org/full/len_full.html
What I see is a rather artistic photo. It surely contains nudity, but it's nonetheless a work of art. If nudity is porn, then Picasso was a pornographer:
http://en.wikipedia.org/wiki/Les_Demoiselles_d'Avignon
And Feynman was also a pornographer then:
http://www.museumsyndicate.com/item.php?item=11504
To cut a long story short. Just because there's nudity, it doesn't mean it's porn. Are we, HN'ers, that prude??