Image-drawing processing system, server, user terminal, image-drawing processing method, program, and storage medium

1. A system, comprising:

circuitry configured to perform:

receiving input information relating to image-drawing and image-erasing;

obtaining more than one image-drawing input stroke and an image-erasing input stroke;

determining that the image-erasing input stroke forms a closed loop when a distance between the beginning and ending points of the closed loop does not exceed a threshold number of pixels;

erasing, using a first erasing process, all coordinates of all the image-drawing input strokes, when any one of the coordinates of at least one image-drawing input stroke exists within the closed loop;

determining that the image-erasing input stroke forms a partially closed loop when the distance between the beginning and ending points of the image-erasing input stroke exceeds the threshold number of pixels;

erasing, using a second erasing process, the portion of the coordinates of the image-drawing input strokes within the partially closed loop;

wherein the circuitry is further configured to perform:

in response to determining that the image-erasing input stroke does not form a loop;

computing a length of the image-erasing input stroke,

generating an erasing area with a width which changes based on the length, the erasing area including regions with the width extending from two sides of each point that forms the image-erasing input stroke, wherein the longer the length of the image-erasing input stroke, the wider the width associated with the erasing area, and

erasing, using a third erasing process, the portion of the coordinates of the image-drawing input strokes within the erasing area.

2. The system of claim 1 , wherein:

a color of a to-be-erased portion of coordinates of the image-drawing input strokes is displayed differently from a color used for displaying the other coordinates of the image-drawing input strokes and image-erasing input stroke.

3. The system of claim 1 , wherein the circuitry is further configured to:

undo erasing of an image-drawing input stroke erased by the image-erasing input stroke.

4. The system according to claim 1 , wherein:

the circuitry is configured such that after the circuitry performs the third erasing process, the width of the erasing area automatically returns to a predetermined width.

5. The system according to claim 1 , wherein:

the third erasing process generates the erasing area to be a region defined by corners having coordinates:

( X 1− a *sin θ, Y 1+ a *cos θ),

( X 1+ a *sin θ, Y 1− a *cos θ)

( X 2+ a *sin θ, Y 2− a *cos θ), and,

( X 2− a *sin θ, Y 2+ a *cos θ),

where:

(X1, Y1) is a first coordinate of the image-erasing input stroke,

(X2, Y2) is a second coordinate of the image-erasing input stroke,

cos θ=(X2−X1)/r,

sin θ=(Y2−Y1)/r,

r=√[(X2−X1) 2 +(Y2−Y1) 2 ], and

“a” corresponds to the length.

6. A non-transitory computer-readable medium storing a program comprising instructions that when executed by a computer cause the computer to execute a method of processing image-drawing, the method comprising the steps of:

receiving input information relating to image-drawing and image-erasing;

obtaining more than one image-drawing input stroke and an image-erasing input stroke;

determining that the image-erasing input stroke forms a closed loop when a distance between the beginning and ending points of the closed loop does not exceed a threshold number of pixels;

erasing, using a first erasing process, all coordinates of all the image-drawing input strokes, when any one of the coordinates of at least one image-drawing input stroke exists within the closed loop;

determining that the image-erasing input stroke forms a partially closed loop when the distance between the beginning and ending points of the image-erasing input stroke exceeds the threshold number of pixels;

erasing, using a second erasing process, the portion of the coordinates of the image-drawing input strokes within the partially closed loop;

wherein the circuitry is further configured to perform:

in response to determining that the image-erasing input stroke does not form a loop;

computing a length of the image-erasing input stroke;

generating an erasing area with a width which changes based on the length, the erasing area including regions with the width extending from two sides of each point that forms the image-erasing input stroke, wherein the longer the length of the image-erasing input stroke, the wider the width associated with the erasing area, and

erasing, using a third erasing process, the portion of the coordinates of the image-drawing input strokes within the erasing area.

7. The non-transitory computer-readable medium according to claim 6 , wherein:

after the third erasing process, the width of the erasing area automatically returns to a predetermined width.

8. The non-transitory computer-readable medium according to claim 6 , wherein:

the third erasing process generates the erasing area to be a region defined by corners having coordinates:

( X 1− a *sin θ, Y 1+ a *cos θ),

( X 1+ a *sin θ, Y 1− a *cos θ)

( X 2+ a *sin θ, Y 2− a *cos θ), and,

( X 2− a *sin θ, Y 2+ a *cos θ),

where:

(X1, Y1) is a first coordinate of the image-erasing input stroke,

(X2, Y2) is a second coordinate of the image-erasing input stroke,

cos θ=(X2−X1)/r,

sin θ=(Y2−Y1)/r,

r=√[(X2−X1) 2 +(Y2−Y1) 2 ], and

“a” corresponds to the length.

9. A computer implemented method, comprising:

receiving input information relating to image-drawing and image-erasing;

obtaining more than one image-drawing input stroke and an image-erasing input stroke;

determining that the image-erasing input stroke forms a closed loop when a distance between the beginning and ending points of the closed loop does not exceed a threshold number of pixels;

erasing, using a first erasing process, all coordinates of all the image-drawing input strokes, when any one of the coordinates of at least one image-drawing input stroke exists within the closed loop;

determining that the image-erasing input stroke forms a partially closed loop when the distance between the beginning and ending points of the image-erasing input stroke exceeds the threshold number of pixels;

erasing, using a second erasing process, the portion of the coordinates of the image-drawing input strokes within the partially closed loop;

wherein the circuitry is further configured to perform:

in response to determining that the image-erasing input stroke does not form a loop;

computing a length of the image-erasing input stroke;

generating an erasing area with a width which changes based on the length, the erasing area including regions with the width extending from two sides of each point that forms the image-erasing input stroke, wherein the longer the length of the image-erasing input stroke, the wider the width associated with the erasing area, and

erasing, using a third erasing process, the portion of the coordinates of the image-drawing input strokes within the erasing area.

10. The method according to claim 9 , wherein:

after the third erasing process, the width of the erasing area automatically returns to a predetermined width.

11. The computer implemented according to claim 9 , wherein:

the third erasing process generates the erasing area to be a region defined by corners having coordinates:

( X 1− a *sin θ, Y 1+ a *cos θ),

( X 1+ a *sin θ, Y 1− a *cos θ)

( X 2+ a *sin θ, Y 2− a *cos θ), and,

( X 2− a *sin θ, Y 2+ a *cos θ),

where:

(X1, Y1) is a first coordinate of the stroke of the image-erasing input stroke,

(X2, Y2) is a second coordinate of the stroke of the image-erasing input stroke,

cos θ=(X2−X1)/r,

sin θ=(Y2−Y1)/r,

r=√[(X2−X1) 2 +(Y2−Y1) 2 ], and

“a” corresponds to the length.

12. An image drawing processing system, comprising:

one or more user terminals; and

a server couplable with each other via a network, the server to process information from each of the user terminals,

wherein each of the user terminals include circuitry configured to:

receive information relating to image-drawing and information relating to image-erasing;

obtain more than one image-drawing input strokes and an image-erasing input stroke;

to determine that the image-erasing input stroke forms a closed loop when a distance between the beginning and ending points of the loop does not exceed a threshold number of pixels;

to erase, using a first erasing process, all coordinates of all the image-drawing input strokes, when any of the coordinates of the of at least one image-drawing input strokes exists within the closed loop;

to determine that the image-erasing input stroke forms a partially closed loop when the distance between the beginning and ending points of the image-erasing input stroke exceeds the threshold number of pixels;

erasing, using a second erasing process, the portion of the coordinates of the image-drawing input strokes within the partially closed loop;

in response to determining that the image-erasing input stroke does not form a loop;

compute a length of the image-erasing input stroke,

generating an erasing area with a width which changes based on the length, the erasing area including regions with the width extending from two sides of each point that forms the image-erasing input stroke, wherein the longer the length of the image-erasing input stroke, the wider the width associated with the erasing area, and

erasing, using a third erasing process, the potion of the coordinates of the image-drawing input strokes within the erasing area;

wherein the server includes circuitry configured to:

to receive the information relating to image-drawing and the information relating to image-erasing from each of the user terminals;

obtain image-drawing input information that is intersecting with the image-erasing input information as intersecting-image information; and

divide the intersecting-image information.

13. The image drawing processing system according to claim 12 , wherein:

the width of the third erasing process which changes based on length erases the area defined by corners having coordinates:

( X 1− a *sin θ, Y 1+ a *cos θ),

( X 1+ a *sin θ, Y 1− a *cos θ)

( X 2+ a *sin θ, Y 2− a *cos θ), and,

( X 2− a *sin θ, Y 2+ a *cos θ),

where:

(X1, Y1) is a first coordinate of the stroke of the image-erasing input stroke,

(X2, Y2) is a second coordinate of the stroke of the image-erasing input stroke,

cos θ=(X2−X1)/r,

sin θ=(Y2−Y1)/r,

r=√[(X2−X1) 2 +(Y2−Y1) 2 ], and

“a” corresponds to the length.