Method and apparatus for adjusting the display scale of an image

• US 6,535,233 B1
• Filed: 11/22/1999
• Issued: 03/18/2003
• Est. Priority Date: 11/20/1998
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Smith, Andrew John
• Primary Examiner(s): Bayerl, Raymond J.
• Application Number:
  US09/444,983
• Time in Patent Office: 1,212 Days
• Field of Search: 345/856, 345/764, 345/859, 345/861, 345/964, 345/428, 345/660, 345/661, 345/665, 345/667, 345/668, 345/860, 345/863, 345/160, 345/157, 345/159, 345/168, 707/502
• US Class Current: 715/856
• CPC Class Codes: G06F 2203/04806 Zoom, i.e. interaction techniques or interactors for controlling the zooming operation
• CPC Class Codes: G06F 3/04845 for image manipulation, e.g. dragging, rotation, expansion or change of colour
• CPC Class Codes: G06T 3/40 Scaling of whole images or parts thereof, e.g. expanding or contracting

Abstract

In a graphical application which allows an image to be displayed according to a display scale, a method of adjusting the display scale during modification of the image. The method responds to user selection of a modification to be performed on the image by storing the current display scale. Then the current display scale is automatically adjusted during modification of the image and in response to user completion of the modification the stored display scale is automatically returned. In a preferred embodiment, the velocity of a pointing device is measured and the display scale is adjusted as a function of the velocity of the pointing device during graphical modification and before the display of the image is re-centered on the pointing device position.

Claims

1. In a graphical application where an image is displayed according to a display scale, a method of adjusting the display scale during modification of said image by a user, comprising the following steps:

a. responsive to user selection of a modification to be performed on said image, automatically storing a current display scale;

b. automatically adjusting the displayed scale of said image in accordance with cursor movements during modification of said image; and

c. responsive to user completion of said modification, automatically returning the displayed scale of said image to the stored display scale.

2. In a graphical application where an image is displayed according to a display scale, a method of adjusting the display scale during modification of said image, comprising the following steps:

a. responsive to user selection of a modification to be performed on said image, storing the display scale;

b. adjusting the display scale during modification of the image; and

c. responsive to user completion of said modification, returning to the stored display scale,

wherein said graphical application is responsive to pointing device movements and the step of adjusting the display scale includes;

b1. measuring the velocity of the pointing device during said graphical modification;

b2. adjusting the display scale as a function of the velocity of the pointing device during said graphical modification; and

b3. re-centering the display of said image on the pointing device position.

3. A method according to claim 2 wherein said modification is one of a transformation of a graphical entity or an addition of a graphical entity.

4. A method according to claim 3 wherein said transformation is one of translation, rotation, scaling or inversion of a graphical entity.

5. A method according to claim 3 wherein said addition of a graphical entity is one of a line draw, a polyline draw, a shape draw, a text box insertion or a graphic insertion.

6. A method according to claim 2 in which said pointer device includes a button and said user selection comprises the user clicking on a menu option indicating the required modification.

7. A method according to claim 6 in which said user completion comprises the user clicking the mouse button.

8. A method according to claim 2 in which the step of adjusting the display scale includes:

b1.1. determining an intricacy value for the image surrounding the centre of said image display;

and wherein adjustment of the display scale is limited in inverse proportion to said image intricacy value.

9. A method according to claim 2 wherein the step of adjusting the display scale is carried out periodically.

10. A method according to claim 2 wherein said adjusting function is one of a linear, and exponential or a ratchet function.

11. A method according to claim 2 wherein said adjustment of said display scale is in inverse proportion to the velocity of the pointing device.

12. In a graphical application where an image is displayed according to a display scale, a method of adjusting the display scale during modification of said image, comprising the following steps:

a. responsive to user selection of a modification to be performed on said image, storing the display scale;

b. adjusting the display scale during modification of the image; and

c. responsive to user completion of said modification, returning to the stored display scale,

wherein said graphical application is responsive to keyboard keystrokes indicating cursor movement and the step of adjusting the display scale includes;

b1. measuring the frequency of cursor movement keystrokes during said graphical modification;

b2. adjusting the display scale as a function of the cursor movement keystroke frequency; and

b3. re-centering the display of said image according to a direction indicated by said cursor movement keystrokes.

13. A method according to claim 12 wherein keyboard keystrokes are arrow keys.

14. A graphical application comprising means for displaying an image according to a display scale, including means for automatically adjusting the display scale during modification of said image by a user, said means comprising:

a. means, responsive to user selection of a modification to be performed on said image, for storing a current display scale;

b. means for automatically adjusting the displayed scale of said image in accordance with cursor movements during modification of said image by said user; and

c. means, responsive to user completion of said modification, for automatically returning the displayed scale of said image to the stored display scale.

15. A computer program product comprising computer program code stored on a computer readable storage medium for, when executed on a computer, providing a graphical application where a display scale is adjusted during modification of an image, the program code comprising a graphical application as claimed in claim 14.