Browse Prior Art Database

User Interface for Adjusting Video Source Area

IP.com Disclosure Number: IPCOM000105831D
Original Publication Date: 1993-Sep-01
Included in the Prior Art Database: 2005-Mar-20
Document File: 4 page(s) / 120K

Publishing Venue

IBM

Related People

Bradley, JJL: AUTHOR [+4]

Abstract

An interface is disclosed that provides a user with the ability to scroll, zoom and stretch incoming video for viewing. The user sees video displayed in a video window and can tailor the shape and extent of the video using mouse and/or keyboard. Digital readouts show the precise relations between the rectangle of video being viewed and the available incoming video.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 47% of the total text.

User Interface for Adjusting Video Source Area

      An interface is disclosed that provides a user with the ability
to scroll, zoom and stretch incoming video for viewing.  The user
sees video displayed in a video window and can tailor the shape and
extent of the video using mouse and/or keyboard.  Digital readouts
show the precise relations between the rectangle of video being
viewed and the available incoming video.

      The IBM M-Motion Video Adapter/A and the M-Motion Control
Program for DOS and OS/2* support the ability to select rectangular
areas of various sizes for the video destination area and the video
source area.  A destination area is any rectangular area of the video
screen being viewed by the user.  A source area is any rectangular
area of the invisible video source buffer.  The M-Control Program
projects the source area into the destination area and modifies the
source area, if necessary, to make it fit into the destination area.

      A conventional method, such as a graphics sizing rectangle, is
used to mark the destination area.  Pressing a specified key or mouse
button initiates the operation of adjusting the source area.  While
adjusting the source area, the operator may:

          Scroll the source area.
          Zoom the source area.
          Stretch or compact the source area vertically or
     horizontally.

          Feedback to the operator is provided by:

          Changes in the displayed video image.
          Digital readouts of the source area position.
          Digital readouts of area proportions.

      Pressing a specified key or mouse button terminates the
operation of adjusting the source area.

      The scrolling of the Video Source is controlled using cursor
control keys (Up, Down, Left, and Right).  The visual effect is that
the destination area is a viewport showing a portion of the video
source buffer; the entire video source buffer can be inspected by
scrolling portions of it into view.  The program code performs this
operation by keeping a source area of a constant size but changing
its location within the video source buffer in response to the key
presses.

      The zooming of the Video Source is controlled using the Plus
(+) and Minus (-) keys.  The visual effect is that the destination
area is a zoom lens which can be adjusted to make the video image
larger or smaller.  The program code performs this operation by using
different sizes of source area.  A smaller source area results in a
larger image (zoom in); a larger source area results in a smaller
image (zoom out).  The source area is kept in a constant aspect ratio
(width-to-height ratio) and is kept centered on the same point in the
video source buffer.  The source area is not allowed to become
smaller than the destination area.

      The stretching or compacting of the Video Source is controlled
by Ctrl-cursor keys (Ctrl-...