Image enhancing brush using minimum curvature solution

Abstract

Systems and methods are provided for enhancing an image by removing defects or blemishes from the image. A user selects a region of one or more pixels to be altered or modified. Interpolation techniques are used to determine interpolated values for pixels in the selected region based on the values of pixels surrounding the selected region. Thereafter, a smoothing function determines new values for each pixel in the selected region based on the values of pixels adjacent to the pixel being smoothed. The smoothing function kernel is applied iteratively to the pixels in the selected region until the image is smoothed to a desired degree.

What is claimed is:  
     
       1. A method of calculating new values for pixels in an image desired to be altered, comprising the steps of: 
       a) providing an image, said image including:  
       a region of one or more first pixels desired to be altered, and  
       a perimeter surrounding said region and comprising second pixels having known values;  
       b) calculating a pixel value for each of said first pixels using linear interpolation based on at least a portion of said second pixels;  
       c) applying a smoothing function to said first pixels, wherein said function recalculates said pixel values for each of said first pixels based on the value of at least the first and second pixels adjacent the pixel being recalculated, said recalculation using the previously calculated pixel values for said first adjacent pixels; and  
       d) repeating step c) if a stop condition is not satisfied, wherein said recalculation uses the previously recalculated pixel values for said first adjacent pixels.  
     
     
       2. The method of claim  1 , further comprising the step of determining a sum of the changes in each of said first pixel values during each iteration of step c), wherein said stop condition is satisfied when said sum is smaller than a predetermined value. 
     
     
       3. The method of claim  1 , further comprising the step of determining the average change in value of said first pixels during an iteration of step c), wherein said stop condition is satisfied when said average is smaller than a predetermined value. 
     
     
       4. The method of claim  1 , further comprising the step of determining, for each iteration of step c), a maximum value corresponding to the change in value of one of said first pixels having the maximum change during step c), wherein said stop condition is satisfied when said maximum value is smaller than a predetermined value. 
     
     
       5. The method of claim  1 , further comprising the step of entering an iteration number N, wherein said stop condition is satisfied if step c) has been repeated N times. 
     
     
       6. The method of claim  1 , wherein said image is a digital image, and wherein said step of providing an image includes the step of selecting said first pixels with a computer generated brush. 
     
     
       7. The method of claim  1 , wherein said image is a two-dimensional image, and wherein said calculating step b) uses four-way linear interpolation. 
     
     
       8. The method of claim  1 , wherein said image is an N-dimensional image, wherein N is an integer greater than two. 
     
     
       9. The method of claim  1 , wherein said smoothing function is a minimum curvature solution algorithm. 
     
     
       10. A method of enhancing a computer generated image, comprising the steps of: 
       a) acquiring a digital image;  
       b) selecting a portion of said image, said portion including a plurality of first pixels, said portion surrounded by second pixels having known values;  
       c) calculating a pixel value for each of said first pixels using linear interpolation based on the known values of at least a portion of said second pixels; and  
       d) iteratively applying a minimum curvature algorithm to said first pixels until a stop condition is satisfied, wherein said algorithm recalculates said pixel values for each of said first pixels based on the value of at least the first and second pixels adjacent the pixel being recalculated, said recalculation using previously calculated pixel values for any of said first adjacent pixels.  
     
     
       11. The method of claim  10 , further comprising the step of displaying said image using said recalculated values of said first pixels, after said stop condition is satisfied. 
     
     
       12. The method of claim  10 , further comprising the step of determining a sum of the changes in each of said first pixel values during each iteration of step d), wherein said stop condition is satisfied when said sum is smaller than a predetermined value. 
     
     
       13. The method of claim  10 , further comprising the step of determining the average change in value of said first pixels during each iteration of step d), wherein said stop condition is satisfied when said average is smaller than a predetermined value. 
     
     
       14. The method of claim  10 , further comprising the step of determining, for each iteration of step d), a maximum value corresponding to the change in value of one of said first pixels having the maximum change during step d), wherein said stop condition is satisfied when said maximum value is smaller than a predetermined value. 
     
     
       15. The method of claim  10 , further comprising the step of entering an iteration number N, wherein said stop condition is satisfied if step d) has been repeated N times. 
     
     
       16. The method of claim  10 , wherein said step of selecting includes the step of selecting said first pixels with a computer generated brush. 
     
     
       17. The method of claim  10 , wherein said digital image is a two-dimensional digital image, and wherein said calculating step b) uses four-way linear interpolation. 
     
     
       18. The method of claim  10 , wherein said digital image is an N-dimensional digital image, wherein N is an integer greater than two. 
     
     
       19. The method of claim  10 , wherein said smoothing function is a minimum curvature solution algorithm. 
     
     
       20. An image processing system, comprising: 
       a) means for providing an image;  
       b) means for selecting a portion of said image, said portion including a plurality of first pixels, said portion surrounded by second pixels having known values;  
       c) a processor, wherein said processor calculates an initial pixel value for each of said first pixels using linear interpolation based on the known values of at least a portion of said second pixels, and wherein the processor thereafter iteratively applies a smoothing function to each of said first pixels until a stop condition has been satisfied, said function recalculating each of said first pixel values using the pixel values of at least the pixels adjacent the pixel being recalculated; and  
       d) means for displaying said image using the recalculated values of said first pixels after said stop condition has been satisfied.  
     
     
       21. The system of claim  20 , wherein said means for displaying includes one of a monitor and a printer. 
     
     
       22. The system of claim  20 , wherein said means for selecting includes a computer generated brush. 
     
     
       23. The system of claim  20 , wherein said providing means includes means for providing a two-dimensional digital image, and wherein said processor calculates said initial pixel values using four-way linear interpolation. 
     
     
       24. The system of claim  20 , wherein said providing means includes means for providing an N-dimensional digital image, wherein N is an integer greater than two. 
     
     
       25. The system of claim  20 , wherein said smoothing function is a minimum curvature solution algorithm. 
     
     
       26. The system of claim  20 , wherein said processor further determines a sum of the changes in each of said first pixel values during each iteration of said smoothing function, and wherein said stop condition is satisfied when said sum is smaller than a predetermined value. 
     
     
       27. The system of claim  20 , wherein said processor further determines the average change in value of said first pixels during each iteration of said smoothing function, wherein said stop condition is satisfied when said average is smaller than a predetermined value. 
     
     
       28. The system of claim  20 , wherein said processor further determines, for each iteration of said smoothing function, a maximum value corresponding to the change in value of one of said first pixels having the maximum change during each iteration, wherein said stop condition is satisfied when said maximum value is smaller than a predetermined value. 
     
     
       29. The system of claim  20 , further comprising means for entering an iteration number N, wherein said stop condition is satisfied when said smoothing function has been applied N times.