Method and apparatus for blending images

Abstract

A method and apparatus may include aligning a reference image and an input image through ROI-based image alignment; detecting an ROI associated with an incompletely aligned region in the aligned image; and blending the aligned reference image and input image by using a plurality of weights which are attenuated according to a spatial distance from a boundary of the detected ROI. In addition, the method and apparatus may include aligning a reference image and an input image through image alignment based on an n th region of interest (ROI) which is detected at a previous stage; detecting another ROI associated with an incompletely aligned region in the aligned image; and blending the aligned image in the other ROI and an (n+1) th blended image, which is input from a next stage, in a region outside the other ROI, and outputting the last blended image to the previous stage.

What is claimed is: 
     
         1 . A method for blending images, comprising:
 aligning a reference image and an input image through region of interest (ROI)-based image alignment;   detecting an ROI associated with an incompletely aligned region in the aligned image; and   blending the aligned input image and reference image by using a plurality of weights which are attenuated according to a spatial distance from a boundary of the detected ROI.   
     
     
         2 . The method of  claim 1 , wherein blending the aligned input image and reference image comprises blending two images by taking the reference image in the ROI and the input image in a region outside the ROI. 
     
     
         3 . The method of  claim 1 , wherein detecting the ROI comprises detecting a ghost. 
     
     
         4 . The method of  claim 1 , wherein the weights are more greatly attenuated at an edge of an image than at other portions of the image. 
     
     
         5 . The method of  claim 1 , wherein the weights are attenuated depending on a difference in brightness level which occurs in the boundary of the ROI. 
     
     
         6 . A method for blending images, comprising:
 aligning a reference image and an input image through image alignment based on an n th  region of interest (ROI) which is detected at a previous stage;   detecting another ROI associated with an incompletely aligned region in the aligned image;   blending the aligned image in the other ROI and an (n+1) th  blended image, which is input from a next stage, in a region outside the other ROI; and   outputting the last blended image to the previous stage.   
     
     
         7 . The method of  claim 6 , wherein detecting the other ROI comprises detecting a ghost. 
     
     
         8 . The method of  claim 6 , further comprising outputting an (n+1) th  ROI, which is an overlapped portion between the n th  ROI and the other ROI, to a next stage. 
     
     
         9 . The method of  claim 6 , wherein blending the aligned image and the (n+1) th  blended image comprises blending the two images by using a plurality of weights which are attenuated according to a spatial distance from a boundary of the other ROI. 
     
     
         10 . The method of  claim 9 , wherein the weights are more greatly attenuated at an edge of an image than at the other portions of the image. 
     
     
         11 . The method of  claim 9 , wherein the weights are attenuated depending on a difference in brightness level which occurs in the boundary of the other ROI. 
     
     
         12 . An image blender, comprising:
 an image aligning unit configured to align a reference image and an input image through ROI-based image alignment;   an ROI detecting unit configured to detect an ROI associated with an incompletely aligned region by detecting motion in an aligned image output from the image alignment unit;   a weight calculating unit configured to calculate a plurality of weights which are attenuated depending on a spatial distance from a boundary of the ROI detected by the ROI detecting unit; and   an image blending unit comprising a processor, the image blending unit configured to blend an aligned image output from the image aligning unit and a reference image according to the weights which are calculated by the weight calculating unit.   
     
     
         13 . The image blender of  claim 12 , wherein the ROI detecting unit comprises a ghost detecting unit configured to detect a ghost. 
     
     
         14 . An image blender, comprising:
 an image aligning unit configured to align a reference image and an input image through image alignment, based on an n th  ROI which is detected at a previous stage;   an ROI detecting unit configured to detect another ROI associated with an incompletely aligned region, based on motion detection in an aligned image output from the image aligning unit; and   an image blending unit comprising a processor, the image blending unit configured to:
 blend the aligned input image in the other ROI and an (n+1) th  blended image, which is input from a next stage, in a region outside the other ROI; and 
 output the last blended image to the previous stage. 
   
     
     
         15 . The image blender of  claim 14 , wherein the ROI detecting unit comprises a ghost detecting unit configured to detect ghosts, based on motion detection in the aligned image output from the image aligning unit. 
     
     
         16 . The image blender of  claim 14 , wherein the ROI detecting unit is further configured to output an (n+1) th  ROI, which is an overlapped portion between the n th  ROI and the other ROI, to a next stage. 
     
     
         17 . The image blender of  claim 14 , further comprising a weight calculating unit configured to calculate a plurality of weights, the image blending unit being further configured to blend the two images using the plurality of weights, the plurality of weights being attenuated depending on a spatial distance from a boundary of the other ROI. 
     
     
         18 . An image blending apparatus, comprising:
 is a plurality of image blenders, at least two of the plurality of image blenders comprising:
 an image aligning unit configured to align a reference image and an input image through image alignment, based on an n th  ROI which is detected at a previous stage; 
 an ROI detecting unit configured to detect another ROI associated with an incompletely aligned region, based on motion detection in an aligned image output from the image aligning unit; and 
 an image blending unit comprising a processor, the image blending unit configured to:
 blend the aligned image in the other ROI and an (n+1) th  blended image, which is input from a next stage, in a region outside the other ROI; and 
 
 output the last blended image to the previous stage. 
   
     
     
         19 . The image blending apparatus of  claim 18 , wherein the plurality of image blenders are cascaded. 
     
     
         20 . The image blending apparatus of  claim 19 , wherein an initial ROI of the first stage image blender is set to a low-brightness region, or a high-brightness region. 
     
     
         21 . A non-transitory computer-readable information storage medium storing a program for causing a computer to implement the method of  claim 1 . 
     
     
         22 . A non-transitory computer-readable information storage medium storing a program for causing a computer to implement the method of  claim 6 .