Image processing for expressing gradation
OwnerIkuo Hayaishiinventor
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Abstract
An image processing technology to correct pixel values of input pixels is provided. First, a conversion relationship indicating the relationship between input pixel values and first tone-corrected values obtained by correction of the input pixel values is established. Based on this conversion relationship, the input pixel values are then converted to first tone-corrected values having a higher number of bits than the input pixels. From the first tone-corrected values, second tone-corrected values having a smaller number of bits than the first tone-corrected values are then generated. During this process, the second tone-corrected values is generated such that a tone of the first tone-corrected values is reproduced by multiple second tone-corrected values for multiple mutually adjacent pixels.
Claims24
An image processing method for correcting pixel values of input pixels, comprising the steps of:
- (i) establishing a conversion relationship that indicates relationship between the input pixel values and first tone-corrected values which are corrected from the input pixel values;
- (ii) converting the input pixel values according to the conversion relationship into the first tone-corrected values having a higher number of bits than the input pixel values;
- and
- (iii) generating from the first tone-corrected values second tone-corrected values having a smaller number of bits than the first tone-corrected values, wherein the step (iii) generates the second tone-corrected values such that a tone of the first tone-corrected values is expressed by a plurality of the second tone-corrected values for a plurality of mutually adjacent pixels.
An image processing apparatus for correcting pixel values of input pixels, comprising:
- a memory configured to store a conversion relationship that indicates relationship between the input pixel values and first tone-corrected values which are corrected from the input pixel values;
- a first processing module configured to convert the input pixel values according to the conversion relationship into the first tone-corrected values having a higher number of bits than the input pixel values;
- and
- a second processing module configured to generating from the first tone-corrected values second tone-corrected values having a smaller number of bits than the first tone-corrected values, wherein the second processing module generates the second tone-corrected values such that a tone of the first tone-corrected values is expressed by a plurality of the second tone-corrected values for a plurality of mutually adjacent pixels.
A computer program, stored on a computer readable medium, for correcting pixel values of input pixels for causing a computer to implement:
- a first processing function to convert the input pixel values, according to conversion relationship that indicates relationship between the input pixel values and first tone-corrected values which are corrected from the input pixel values, into the first tone-corrected values having a higher number of bits than the input pixel values;
- and
- a second processing function to generating from the first tone-corrected values second tone-corrected values having a smaller number of bits than the first tone-corrected values, wherein the second processing function generates the second tone-corrected values such that a tone of the first tone-corrected values is expressed by a plurality of the second tone-corrected values for a plurality of mutually adjacent pixels.
Dependencies are inferred from the claim text.