Image processing apparatus and image processing method thereof

1. An image processing method of an image processing apparatus, the method comprising:

discerning pixels to be processed on the basis of a preset reference pixel value in a scanned image that comprises a plurality of pixels;

drawing a pixel area including the pixels to be processed from the scanned image on the basis of a preset condition; and

selecting whether to apply an image process to the pixels to be processed or the drawn pixel area on the basis of a percentage of the pixels to be processed in the drawn pixel area,

wherein selecting the pixels to be processed when the percentage is larger than a predetermined value, and selecting the drawn pixel area when the percentage is smaller than a predetermined value.

2. The method according to claim 1 , wherein the selecting comprises comparing a function Y satisfying the following expression with a preset value, and selecting the pixels to be processed if the Y is less than or equal to the preset value, and the drawn pixel area if the Y is more than the preset value,

Y ={( Cp−Rp )/ Cp}* 100[%]  <Expression 1>

where, Cp indicates the number of pixels in the drawn pixel area, and Rp indicates the number of pixels to be processed.

3. The method according to claim 1 , wherein the drawing the pixel area comprises drawing a pixel area within a polygon formed by a convex hull algorithm.

4. The method according to claim 3 , wherein the drawing the pixel area within the polygon comprises forming the polygon with outmost pixels among the pixels to be processed.

5. The method according to claim 4 , wherein the forming the polygon comprises:

forming an octagon including the pixels to be processed thereinside; and

drawing the polygon formed by lines at positions where the lines are first in contact with the pixels to be processed, while making the lines constituting the octagon approach a center of the octagon.

6. The method according to claim 1 , wherein the discerning the pixels to be processed comprises selecting pixels corresponding to an area scanned unrelated to the object in the scanned image, and designating a pixel value of the selected pixel as the reference pixel value.

7. The method according to claim 6 , wherein the selecting pixels corresponding to an area scanned unrelated to the object in the scanned image comprises selecting at least one pixel among the pixels positioned at edges of the scanned image.

8. The method according to claim 7 , wherein the discerning the pixels to be processed comprises discerning the pixels in order of being adjacent to the selected pixels among the plural pixels of the scanned image.

9. An image processing apparatus comprising:

a scanning unit which scans an object and outputs a scanned image; and

an image processing unit which discerns pixels to be processed on the basis of a preset reference pixel value in the scanned image that comprises a plurality. of pixels, draws a pixel area including the pixels to be processed from the scanned image on the basis of a preset condition, selects the pixels to be processed or the drawn pixel area on the basis of a percentage of the pixels to be processed in the drawn pixel area, and applies an image process to the scanned image according to results of the selection, wherein selecting the pixels to be processed when the percentage is larger than a predetermined value, and selecting the drawn pixel area when the percentage is smaller than a predetermined value.

10. The image processing apparatus according to claim 9 , wherein the image processing unit compares a function Y satisfying the following expression with a preset value, and selects the pixels to be processed if the Y is less than or equal to the preset value, and the drawn pixel area if the Y is more than the preset value,

Y ={( Cp−Rp )/ Cp}* 100[%]  <Expression 2>

where, Cp indicates the number of pixels in the drawn pixel area, and Rp indicates the number of pixels to be processed.

11. The image processing apparatus according to claim 9 , wherein the image processing unit draws the pixel area depending on a polygon formed by a convex hull algorithm.

12. The image processing apparatus according to claim 11 , wherein the image processing unit forms the polygon with outmost pixels among the pixels to be processed.

13. The image processing apparatus according to claim 12 , wherein the image processing unit forms an octagon including the pixels to be processed thereinside;

making lines constituting the octagon approach a center of the octagon; and draws the polygon formed by the lines at positions where the lines are first in contact with the pixels to be processed.

14. The image processing apparatus according to claim 9 , wherein the image processing unit selects pixels corresponding to an area scanned unrelated to the object in the scanned image, and designates a pixel value of the selected pixel as the reference pixel value.

15. The image processing apparatus according to claim 14 , wherein the image processing unit selects at least one pixel among the pixels positioned at edges of the scanned image.

16. The image processing apparatus according to claim 15 , wherein the image processing unit discerns the pixels in order of being adjacent to the selected pixel among the plural pixels of the scanned image.

17. An image processing method, comprising:

generating a first binary mask of pixels including first pixels to be processed and second pixels not to be processed;

generating a second binary mask of pixel areas including first pixel areas each of which includes at least one pixel among the first pixels and second pixel areas which do not include the first pixels; and

selecting whether to apply an image process to the first pixels or the first pixel area on the basis of a percentage of the of the first pixel in the first pixel area, wherein selecting the first pixels when the percentage is larger than a predetermined value, and selecting the first pixel area when the percentage is smaller than a predetermined value.

18. The method of claim 17 , wherein the preset range of the pixel value of the pixel may be a reference pixel value corresponding to a scanned part unrelated to an object in a scanned image.