Image correction method, apparatus, article and image

Abstract

An image correction method able to avoid error image. According to opposite properties of black and white, only the last few bits of the scanned digital signal are extracted for black correction, while only the first few bits of the scanned digital signal are extracted for white correction. Further, the most significant bit of the digital signal is 1 for white correction. Therefore, the unwanted LBB effect on the scanned image caused by dust or spots on the correction document is avoided. In addition, as only a few bits of the scanned digital signal are extracted, the requirement in memory capacity is reduced.

1 . An apparatus, comprising:
 means for obtaining a black correction digital signal by scanning a document during black correction, wherein the black correction digital signal comprises a plurality of bits;   means for extracting only a portion of the plurality of bits of the black correction digital signal; and   means for storing only the extracted portion of the plurality of bits of the black correction digital signal in a memory.   
     
     
         2 . The apparatus of  claim 1 , further comprising:
 means for obtaining a white correction digital signal comprising a plurality of bits; and   means for extracting only a portion of the plurality of bits of the white correction digital signal.   
     
     
         3 . The apparatus of  claim 2 , further comprising means for setting a most significant bit of the white correction digital signal to a value of one. 
     
     
         4 . The apparatus of  claim 2 , further comprising means for storing only the extracted portion of the plurality of bits of the white correction digital signal in the memory. 
     
     
         5 . The apparatus of  claim 1 , wherein the document comprises a black correction document. 
     
     
         6 . The apparatus of  claim 1 , further comprising:
 means for scanning the document to obtain a correction analog signal; and   means for converting the correction analog signal into the black correction digital signal.   
     
     
         7 . The apparatus of  claim 6 , wherein the means for scanning comprises a charge-coupled device. 
     
     
         8 . An apparatus, comprising:
 a processing device configured to:   scan a target object during black correction to obtain a black correction digital signal comprising a plurality of bits;   extract only a portion of the plurality of bits of the black correction digital signal; and   store only the extracted portion of the plurality of bits of the black correction digital signal in a memory;   wherein a value of at least a particular bit of the plurality of bits of the black correction digital signal having a most significant bit position of the plurality of bits of the black correction digital signal is discarded without being stored.   
     
     
         9 . The apparatus of  claim 8 , wherein the processing device is configured to:
 obtain a white correction digital signal comprising a plurality of bits; and   extract only a portion of the plurality of bits of the white correction digital signal;   wherein a value of at least a particular bit of the plurality of bits of the white correction digital signal having a least significant bit position of the plurality of bits of the white correction digital signal is discarded without being stored.   
     
     
         10 . The apparatus of  claim 9 , wherein the processing device is configured to set a value of at least a particular bit of the plurality of bits of the white correction digital signal having a most significant bit position of the plurality of bits of the white correction digital signal to one. 
     
     
         11 . The apparatus of  claim 9 , wherein the processing device is configured to store only the portion of the plurality of bits of the white correction digital signal in the memory. 
     
     
         12 . The apparatus of  claim 8 , wherein the target object comprises a black correction document. 
     
     
         13 . The apparatus of  claim 8 , wherein the processing device is configured to:
 scan the target object to obtain a correction analog signal; and   convert the correction analog signal into the black correction digital signal.   
     
     
         14 . The apparatus of  claim 13 , wherein the scan is performed using a charge-coupled device. 
     
     
         15 . A method, comprising:
 scanning a target object during black correction to obtain a black correction digital signal comprising a plurality of bits;   extracting only a portion of the plurality of bits of the black correction digital signal; and   storing only the extracted portion of the plurality of bits of the black correction digital signal in a memory;   wherein a value of at least a particular bit of the plurality of bits of the black correction digital signal having a most significant bit position of the plurality of bits of the black correction digital signal is discarded without being stored.   
     
     
         16 . The method of  claim 15 , further comprising:
 obtaining a white correction digital signal comprising a plurality of bits; and   extracting only a portion of the plurality of bits of the white correction digital signal;   wherein a value of at least a particular bit of the plurality of bits of the white correction digital signal having a least significant bit position of the plurality of bits of the white correction digital signal is discarded without being stored.   
     
     
         17 . The method of  claim 16 , further comprising setting a value of at least a particular bit of the plurality of bits of the white correction digital signal having a most significant bit position of the plurality of bits of the white correction digital signal to one. 
     
     
         18 . The method of  claim 16 , further comprising storing only the portion of the plurality of bits of the white correction digital signal in the memory. 
     
     
         19 . The method of  claim 15 , wherein the target object comprises a black correction document. 
     
     
         20 . The method of  claim 15 , further comprising:
 scanning the target object to obtain a correction analog signal; and   converting the correction analog signal into the black correction digital signal.