Drawing apparatus and method, program and recording medium
View Patent ↗Accurate drawing without position displacement is performed irrespective of different aspect ratios on the transmission side of drawing information and on the reception side. In a drawing apparatus 50 , a normalized coordinate transformation section 62 transforms normalized coordinates (x 3 , y 3 ) transmitted via a network into rear coordinates (x 2 , y 3 ) in accordance with an inverse function g 1 −1 of a function g 1 for normalizing an aspect ratio of an image displayed on a display, and a rear coordinate transformation section 63 transforms the rear coordinates (x 2 , y 2 ) into front coordinates (x 1 , y 1 ) in accordance with an inverse function f 1 −1 of a function f 1 corresponding to the aspect ratio of the image. A drawing section 67 draws an image on the screen of the display in accordance with the front coordinates (x 1 , y 1 ). The invention is applicable, for example, to an application sharing drawing information.
1. A drawing apparatus for performing drawing on a screen of a display apparatus in response to position information transmitted from another apparatus and indicating a position on which drawing is performed, the apparatus comprising:
means for enabling a change in aspect ratio;
first transforming mechanism for transforming the position information into first transformed position information in accordance with an inverse function of a first function for normalizing an aspect ratio of an image displayed on the display apparatus which has been changed by the means for enabling;
second transforming mechanism for transforming the first transformed position information into second transformed position information in accordance with an inverse function of a second function, different from the first function, corresponding to the aspect ratio of the image; and
drawing mechanism for drawing an image on the screen of the display apparatus.
2. The drawing apparatus according to claim 1 , further comprising:
third transforming mechanism for transforming drawing input position information, representative of a position of a drawing input over the screen, into third transformed position information based on the second function;
fourth transforming mechanism for transforming the third transformed position information into fourth transformed position information based on the first function; and
transmitter for transmitting the fourth transformed position information to the other apparatus via a network.
3. A drawing method for performing drawing on a screen of a display apparatus in response to position information transmitted from another apparatus and indicating a position on which drawing is performed, the method comprising:
a step of enabling a change in aspect ratio;
a first step of transforming the position information into first transformed position information in accordance with an inverse function of a first function for normalizing an aspect ratio of an image displayed on the display apparatus which has been changed;
a second step of transforming the first transformed position information into second transformed position information in accordance with an inverse function of a second function, different from the first function, corresponding to the aspect ratio of the image; and
a drawing step of drawing an image on the screen of the display apparatus.
4. A computer-readable program to be encoded in computer-readable medium, said program for causing a computer to execute the steps of a method for performing drawing on a screen of a display apparatus in response to position information transmitted from another apparatus and indicating a position on which drawing is performed, the method comprising:
a step of enabling a change in aspect ratio;
a first step of transforming the position information into first transformed position information in accordance with an inverse function of a first function for normalizing an aspect ratio of an image displayed on the display apparatus which has been changed;
a second step of transforming the first transformed position information into second transformed position information in accordance with an inverse function of a second function, different from the first function, corresponding to the aspect ratio of the image; and
a drawing step of drawing an image on the screen of the display apparatus.
5. A recording medium having recorded thereon a computer-readable program for causing a computer to perform the steps of a method for performing drawing on a screen of a display apparatus in response to position information transmitted from another apparatus and indicating a position on which drawing is performed, the method comprising:
a step of enabling a change in aspect ratio;
a first step of transforming the position information into first transformed position information in accordance with an inverse function of a first function for normalizing an aspect ratio of an image displayed on the display apparatus which has been changed;
a second step of transforming the first transformed position information into second transformed position information in accordance with an inverse function of a second function, different from the first function, corresponding to the aspect ratio of the image; and
a drawing step of drawing an image on the screen of the display apparatus.
6. A drawing apparatus for performing drawing on a screen of a display apparatus in response to a drawing input on the screen of the display apparatus, comprising:
means for enabling a change in aspect ratio;
first transforming mechanism for transforming drawing input position information representative of a position of a drawing input into first transformed position information based on a second function, different from a first function for normalizing an aspect ratio of an image displayed on the display apparatus, corresponding to the aspect ratio of the image displayed on the display apparatus which has been changed by the enabling means;
second transforming mechanism for transforming the first transformed position information into second transformed position information in accordance with the first function; and
transmitter for transmitting the second transformed position information to another apparatus via a network.
7. A drawing method for performing drawing on a screen of a display apparatus in response to a drawing input on the screen of the display apparatus, comprising:
a step of enabling a change in aspect ratio;
first transforming step of transforming drawing input position information representative of a position of a drawing input into first transformed position information based on a second function, different from a first function for normalizing an aspect ratio of an image displayed on the display apparatus, corresponding to the aspect ratio of the image displayed on the display apparatus which has been changed;
second transforming step of transforming the first transformed position information into second transformed position information in accordance with the first function; and
transmitting step of transmitting the second transformed position information to another apparatus via a network.
8. A computer-readable program to be encoded in a computer-readable medium, said program for causing a computer to execute the steps of a method for performing drawing on a screen of a display apparatus in response to a drawing input on the screen of the display apparatus, the method comprising:
a step of enabling a change in aspect ratio;
first transforming step of transforming drawing input position information representative of a position of a drawing input into first transformed position information based on a second function, different from a first function for normalizing an aspect ratio of an image displayed on the display apparatus, corresponding to the aspect ratio of the image displayed on the display apparatus which has been changed;
second transforming step of transforming the first transformed position information into second transformed position information in accordance with the first function; and
transmitting step of transmitting the second transformed position information to another apparatus via a network.
9. A recording medium having recorded thereon a computer-readable program for causing a computer to perform the steps of a method for performing drawing on a screen of a display apparatus in response to a drawing input on the screen of the display apparatus, the method comprising:
a step of enabling a change in aspect ratio;
first transforming step of transforming drawing input position information representative of a position of a drawing input into first transformed position information based on a second function, different from a first function for normalizing an aspect ratio of an image displayed on the display apparatus, corresponding to the aspect ratio of the image displayed on the display apparatus which has been changed;
second transforming step of transforming the first transformed position information into second transformed position information in accordance with the first function; and
transmitting step of transmitting the second transformed position information to another apparatus via a network.
10. A drawing apparatus for performing drawing on a screen of a display apparatus in response to position information transmitted from another apparatus and indicating a position on which drawing is performed, the apparatus comprising:
means for enabling a change in aspect ratio;
first transforming means for transforming the position information into first transformed position information in accordance a first function for normalizing an aspect ratio of an image displayed on the display apparatus which has been changed by the means for enabling;
second transforming mechanism for transforming the first transformed position information into second transformed position information in accordance with a second function, different from the first function, corresponding to the aspect ratio of the image; and
drawing mechanism for drawing a desired image on the screen of the display apparatus.