Prior art — US Patent 7292261

Here's an analysis of the most relevant prior art for US Patent 7,292,261, based on the citations listed on its Google Patents page and the independent claims of US7292261.

US Patent 7,292,261 Independent Claims Summary:

Claim 1 (Camera with Viewfinder Overlay): A camera with acquisition circuitry for first and second fields of view, and a viewfinder displaying the second field of view partially composited with a portion of the first field of view. This highlights the real-time alignment assistance feature.
Claim 10 (In-Place Image Conversion Method): A method for converting an image in a buffer from a first coordinate system (e.g., rectilinear) to a second coordinate system (e.g., cylindrical) using a non-linear transformation, by computing and storing color values along axes within the same buffer, thus overwriting the original data. This emphasizes memory efficiency.
Claim 11 (Camera with In-Camera Combining): A camera with acquisition circuitry for first and second frames, and combining circuitry for at least partially combining them into a panoramic image within the camera. This is a core "virtual reality camera" aspect.
Claim 16 (Camera with In-Camera Playback): A camera with memory for a panoramic image, a display, and display control circuitry for selecting and displaying a portion of the panoramic image. This covers the interactive playback feature.
Claim 22 (Method for Combining Frames): A method including steps of determining horizontal and vertical offsets (e.g., using SAD), determining brightness and contrast parameters (e.g., histogram matching), and generating a panoramic image by compositing frames based on these parameters. This details the stitching process.

Identified Prior Art and Analysis:

US6052140A - Image compositing system and method
- Full Citation: US6052140A, Teo, Patrick, "Image compositing system and method"
- Publication/Filing Date: Publication: 2000-04-18, Filing: 1998-03-24 (Priority date: 1997-09-03)
- Brief Description: This patent describes a method and system for compositing images, particularly for creating panoramic images, by dynamically estimating displacement parameters (e.g., horizontal and vertical offsets) and applying color corrections (e.g., brightness and contrast) in an overlap region. It mentions summing absolute differences (SAD) for motion estimation and histogram matching for color correction.
- Potential Anticipation (35 U.S.C. § 102):
  - Claim 22: This patent directly describes methods for determining horizontal and vertical offsets by summing absolute values of color differences (SAD), and determining brightness and contrast parameters for chromatic alignment using histogram matching, which are explicit steps in claim 22. It also describes compositing based on these parameters. This patent, being a co-pending application of the same assignee, is highly relevant for these method steps.
US5923366A - Image compositing method and system
- Full Citation: US5923366A, Teo, Patrick, "Image compositing method and system"
- Publication/Filing Date: Publication: 1999-07-13, Filing: 1998-03-24 (Priority date: 1997-09-03)
- Brief Description: This patent focuses on an image compositing method and system that creates a composite image from multiple input images by determining displacement parameters and applying color correction. It specifically discusses histogram-based color correction for blending images.
- Potential Anticipation (35 U.S.C. § 102):
  - Claim 22: Similar to US6052140A, this patent is also by the same inventor/assignee and predates the filing of US7292261. It describes fundamental methods for chromatic alignment (histogram matching) and potentially spatial alignment in the context of image compositing, which are key elements of claim 22.
US5892534A - Method and apparatus for generating a composite photographic image
- Full Citation: US5892534A, Teo, Patrick, "Method and apparatus for generating a composite photographic image"
- Publication/Filing Date: Publication: 1999-04-06, Filing: 1998-03-24 (Priority date: 1997-09-03)
- Brief Description: This patent describes a method and apparatus for creating a composite photographic image from a plurality of individual images, including steps for aligning and blending images. It discusses determining offsets and color parameters, and applying them to stitch images together.
- Potential Anticipation (35 U.S.C. § 102):
  - Claim 22: This patent (again, by the same inventor/assignee and predating the filing) covers the general concept of aligning, blending, and stitching images to form a composite, which is the essence of claim 22. Specific algorithms like SAD and histogram matching might be detailed further in its specification, making it highly relevant.
US5426743A - Method and apparatus for interactive viewing of panoramic photographic images
- Full Citation: US5426743A, Teo, Patrick, "Method and apparatus for interactive viewing of panoramic photographic images"
- Publication/Filing Date: Publication: 1995-06-20, Filing: 1994-04-18
- Brief Description: This patent describes a method and apparatus for interactively viewing panoramic photographic images, including projecting image data onto a surface geometry (e.g., cylindrical) and displaying portions of it in a rectilinear view window. It also discusses changing magnification (zooming) and angular position (panning).
- Potential Anticipation (35 U.S.C. § 102):
  - Claim 16: This patent, also by Patrick Teo and predating US7292261, clearly teaches the interactive viewing of panoramic images, selecting a portion to display, and dynamic navigation (panning, zooming) through a panoramic image stored in a cylindrical coordinate system, and displaying it in rectilinear coordinates. The novelty in US7292261 for this claim would primarily reside in performing this within the camera rather than on a general client computer, if not explicitly taught here.
  - Claim 10: While primarily about viewing, it inherently touches upon the transformation between coordinate systems (cylindrical to rectilinear for display), though not explicitly "in-place" conversion as claimed by US7292261.
US5349455A - Method for panoramic photographic image capture
- Full Citation: US5349455A, Teo, Patrick, "Method for panoramic photographic image capture"
- Publication/Filing Date: Publication: 1994-09-20, Filing: 1993-02-12
- Brief Description: This patent describes a method for capturing a plurality of photographic images to form a panoramic image, including rotating a camera to capture overlapping images.
- Potential Anticipation (35 U.S.C. § 102):
  - This patent broadly covers the capture aspect of panoramic imaging by rotating a camera and acquiring successive images. While it sets the stage for panoramic image creation, it doesn't appear to specifically disclose the in-camera processing, real-time viewfinder overlay, or in-place conversion as central to US7292261's claims. Its relevance might be more foundational to the overall field of panoramic photography.
US4171520A - Camera and electronic viewfinder with composite image capability
- Full Citation: US4171520A, Machida et al., "Camera and electronic viewfinder with composite image capability"
- Publication/Filing Date: Publication: 1979-10-16, Filing: 1978-05-19
- Brief Description: This patent describes an electronic camera with a viewfinder that can display a composite image, where a newly taken image can be superposed on a previously taken image. This allows a user to confirm the composition and alignment of images.
- Potential Anticipation (35 U.S.C. § 102):
  - Claim 1: This patent is highly relevant to the concept of displaying a previous image composited with a current field of view in a viewfinder for alignment purposes. The core idea of using the viewfinder for real-time visual alignment during successive image capture for compositing appears to be anticipated here, albeit in a general electronic camera context, not specifically for panoramic images, but the principle is similar.

The other patents in the provided list also contribute to the general state of the art in digital imaging, panoramic photography, and camera technology, but the ones detailed above appear to be the most directly anticipatory or relevant to the specific inventive aspects claimed in US7292261 based on their abstracts. The numerous prior art citations by the same inventor/assignee (Patrick Teo and MGI Software/Roxio) indicate a continuous development in the field of panoramic image creation and viewing, with US7292261 building upon or integrating these earlier inventions into a single, in-camera system.