Image processing apparatus, binarization method, and non-transitory recording medium
AssigneeRicoh Company, Ltd.
InventorNoriko Miyagi
Life of this patent
Estimating the term…
Abstract
An image processing apparatus includes circuitry that calculates, based on pixel values of an input image having M gradations, an N−1 first threshold value, wherein M>N>2, compares the pixel values of the input image with the N−1 first threshold value to generate an N-valued image from the input image, and generates, based on pixel values of each of local regions of the input image and gradation values of each of local regions of the N-valued image, a binarized image obtained by binarizing the input image.
Claims13
An image processing apparatus comprising:
- circuitry configured to:
- calculate, based on pixel values of an input image having M gradations, an N−1 first threshold value, wherein M>N>2;
- compare the pixel values of the input image with the N−1 first threshold value to generate an N-valued image from the input image;
- select, based on pixel values of each of local regions of the input image and gradation values of each of local regions of the N-valued image, a binarization method for a pixel of interest of the input image, and
- generate, based on the pixel values of each of local regions of the input image and the gradation values of each of local regions of the N-valued image, a binarized image obtained by using the selected binarization method that binarizes the pixel of interest of the input image based on pixel values of a local region including the pixel of interest in the input image and the gradation values of the local region including the pixel of interest in the N-valued image.
A binarization method performed by an image processing apparatus, the binarization method comprising:
- calculating, based on pixel values of an input image having M gradations, an N−1 first threshold value, wherein M>N>2;
- comparing the pixel values of the input image with the N−1 first threshold value to generate an N-valued image from the input image;
- selecting, based on pixel values of each of local regions of the input image and gradation values of each of local regions of the N-valued image, a binarization method for a pixel of interest of the input image, and
- generating, based on the pixel values of each of local regions of the input image and the gradation values of each of local regions of the N-valued image, a binarized image obtained by using the selected binarization method that binarizes the pixel of interest of the input image based on pixel values of the local region including the pixel of interest in the input image and the gradation values of the local region including the pixel of interest in the N-valued image.
A non-transitory recording medium storing a plurality of instructions which, when executed by one or more processors, causes the one or more processors to perform a binarization method comprising:
- calculating, based on pixel values of an input image having M gradations, an N−1 first threshold value, wherein M>N>2;
- comparing the pixel values of the input image with the N−1 first threshold value to generate an N-valued image from the input image;
- selecting, based on pixel values of each of local regions of the input image and gradation values of each of local regions of the N-valued image, a binarization method for a pixel of interest of the input image, and
- generating, based on the pixel values of each of local regions of the input image and the gradation values of each of local regions of the N-valued image, a binarized image obtained by using the selected binarization method that binarizes the pixel of interest of the input image based on pixel values of the local region including the pixel of interest in the input image and the gradation values of the local region including the pixel of interest in the N-valued image.
Dependencies are inferred from the claim text.