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In this figure we see two similar triangles, both having parts of the projection line (green) as their hypotenuses. The catheti of the left triangle are and f and the catheti of the right triangle are and . Since the two triangles are similar it follows that
Hi, I missed your point about the necessity to provide more specific references in the Pinhole camera model article.
Regards -- KYN 12:48, 28 September 2007 (UTC)
I'm new to Wikipedia and would like to contribute material to this article. To begin with the term "photography" should appear since the purpose of a pinhole camera is to make pinhole photos. More to the point, there is at least one individual of whom I am aware who is a recognized expert on pinhole photography. Wiley Sanderson was head of the photography school at the University of Georgia. Among other things, he required all beginning students to construct and use a pinhole camera during their first year. I'm neither a photographer nor an academic, but he made such a deep impression on me over forty years ago that I never forgot him and what he taught about taking pictures. I told the story at my blog, Hootsbuddy's Place. Any Google search for "Wiley Sanderson" will bring up the link. I would appreciate any feedback. —Preceding unsigned comment added by Hootsbuddy ( talk • contribs) 22:14, 18 August 2008 (UTC)
I'm having some problems with the following statement in the "Projective representation" section:
where is the camera matrix and the sign implies that the left and right hand sides are equal up to a non-zero scalar multiplication.
The left and right-hand side are equal, not just under a non-zero scalar multiplication. The fact that a non-zero scale multiplication of would keep in the same homogeneous equivalence class is irrelevant for this section.
Also, I'm wondering whether the "Projective representation" section shouldn't be called "Homogeneous Coordinates". Naming the section "Projective representation" would imply that the above sections are not a representing a projection. The original author was most likely talking about representation in projective geometry, but it sound slightly vague this way.
Wim ( talk) 16:04, 14 March 2009 (UTC)
Currently the article states "f is also referred to as the focal length of the pinhole camera." This usage is quite distinct from the strict 'optics' definition currently given in focal length. If we had a reliable source to justify it, it would be very helpful to add this 'alternative' definition to the focal length article. -- Redbobblehat ( talk) 15:52, 7 February 2011 (UTC)
Try any of the following:
-- KYN ( talk) 16:32, 7 February 2011 (UTC)
This page mentions "focal point" twice, and Camera matrix links focal point to this page via a redirect. I think the author is trying to talk about the camera center. If so, that's misleading at best. In as much as a pinhole camera models a real camera, the focal point would better be the principal point. Either way, I've never heard "focal point" used with precise meaning in computer vision/graphics. Shall we replace "focal point" with more-precise language? —Ben FrantzDale ( talk) 15:14, 14 July 2011 (UTC)
![]() | A fact from Pinhole camera model appeared on Wikipedia's
Main Page in the
Did you know column on 4 August 2007. The text of the entry was as follows:
| ![]() |
![]() | This article is rated Start-class on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | ||||||||||
|
In this figure we see two similar triangles, both having parts of the projection line (green) as their hypotenuses. The catheti of the left triangle are and f and the catheti of the right triangle are and . Since the two triangles are similar it follows that
Hi, I missed your point about the necessity to provide more specific references in the Pinhole camera model article.
Regards -- KYN 12:48, 28 September 2007 (UTC)
I'm new to Wikipedia and would like to contribute material to this article. To begin with the term "photography" should appear since the purpose of a pinhole camera is to make pinhole photos. More to the point, there is at least one individual of whom I am aware who is a recognized expert on pinhole photography. Wiley Sanderson was head of the photography school at the University of Georgia. Among other things, he required all beginning students to construct and use a pinhole camera during their first year. I'm neither a photographer nor an academic, but he made such a deep impression on me over forty years ago that I never forgot him and what he taught about taking pictures. I told the story at my blog, Hootsbuddy's Place. Any Google search for "Wiley Sanderson" will bring up the link. I would appreciate any feedback. —Preceding unsigned comment added by Hootsbuddy ( talk • contribs) 22:14, 18 August 2008 (UTC)
I'm having some problems with the following statement in the "Projective representation" section:
where is the camera matrix and the sign implies that the left and right hand sides are equal up to a non-zero scalar multiplication.
The left and right-hand side are equal, not just under a non-zero scalar multiplication. The fact that a non-zero scale multiplication of would keep in the same homogeneous equivalence class is irrelevant for this section.
Also, I'm wondering whether the "Projective representation" section shouldn't be called "Homogeneous Coordinates". Naming the section "Projective representation" would imply that the above sections are not a representing a projection. The original author was most likely talking about representation in projective geometry, but it sound slightly vague this way.
Wim ( talk) 16:04, 14 March 2009 (UTC)
Currently the article states "f is also referred to as the focal length of the pinhole camera." This usage is quite distinct from the strict 'optics' definition currently given in focal length. If we had a reliable source to justify it, it would be very helpful to add this 'alternative' definition to the focal length article. -- Redbobblehat ( talk) 15:52, 7 February 2011 (UTC)
Try any of the following:
-- KYN ( talk) 16:32, 7 February 2011 (UTC)
This page mentions "focal point" twice, and Camera matrix links focal point to this page via a redirect. I think the author is trying to talk about the camera center. If so, that's misleading at best. In as much as a pinhole camera models a real camera, the focal point would better be the principal point. Either way, I've never heard "focal point" used with precise meaning in computer vision/graphics. Shall we replace "focal point" with more-precise language? —Ben FrantzDale ( talk) 15:14, 14 July 2011 (UTC)