An example embodiment may involve obtaining an a×b pixel macro-cell from an input image. Pixels in the a×b pixel macro-cell may have respective pixel values and may be associated with respective tags. It may be determined whether at least e of the respective tags indicate that their associated pixels represent edges in the input image. Based on this determination, either a first encoding or a second encoding of the a×b pixel macro-cell may be selected. The first encoding may weigh pixels that represent edges in the input image heavier than pixels that do not represent edges in the input image, and the second encoding might not consider whether pixels represent edges. The selected encoding may be performed and written to a computer-readable output medium.

An example embodiment may involve obtaining (i) an a×b attribute macro-cell, and (ii) a×b pixel macro-cells for each of a luminance plane, a first color plane, and a second color plane of an input image. The a×b pixel macro-cells may each contain 4 non-overlapping m×n pixel cells. The example embodiment may also involve determining 4 attribute-plane output values that represent the 4 non-overlapping m×n attribute cells, 1 to 4 luminance-plane output values that represent the a×b pixel macro-cell of the luminance plane, a first color-plane output value to represent the a×b pixel macro-cell of the first color plane, and a second color-plane output value to represent the a×b pixel macro-cell of the second color plane. The example embodiment may further involve writing an interleaved representation of the output values to a computer-readable output medium.

An image forming apparatus includes a table generating unit. The table generating unit, in a Voronoi diagram, obtains empty circles as circles centered at Voronoi seeds of ends of Voronoi sides that intersect with a straight line passing through a largest saturation color and a smallest-saturation and specific-lightness color and passes through generatrices. After the table generating unit sets one of the generatrices shared by the two adjacent empty circles whose radius ratio is outside a specific range as a target point, and causes the radius ratio of the two empty circles to be within the specific range by changing at least one radius of the two empty circles, the table generating unit generates the conversion table that sets a color that corresponds to an intersection point corresponding to the target point among the intersection points of the two empty circles, as the definition colors.

A binary image of an input image is generated, and a character region within the binary image and a region surrounding each character are acquired as character segmentation rectangle information. A thinning process is executed on a region within the binary image which is identified based on the character segmentation rectangle information to acquire a thinned image. An edge detected image of the region identified based on the character segmentation rectangle information is acquired. Whether each character identified based on the character segmentation rectangle information is a character to be separated from a background by the binarization process or not is determined based on a result of a logical AND of the thinned image and the edge detected image.

A method includes: receiving, at a computing device, image data encoded by delta row encoding, the image data indicating two dimensionally arranged plurality of pixels, the image data including delta data indicating difference between N-th row line and (N−1)th row line in the two dimensionally arranged plurality of pixels; pre-decoding the image data for the N-th row line using the delta data if the delta data has a size equal to or larger than a threshold while keeping the image data for the N-th row line using the delta data if the delta data has a size smaller than the threshold so as to generate intermediate codes using the computing device; and decoding and rendering the kept undecoded lines in the generated intermediate codes while rendering the decoded lines in the generated intermediate codes using the computing device.

A method includes obtaining an image of a document against a background. A bounding box that bounds a region of the image that is distinguishable from the background is found. Coordinates of a plurality of points of the distinguishable region are found, each point being a point of the distinguishable region that is closest to each corner of the bounding box. The document is identified within the image as a region of the image whose corners are defined by the found coordinates.

An image compressing device includes: a histogram creating unit configured to create a histogram regarding an input image; an original type recognizing unit configured to recognize an original type of the input image using the histogram; and an image compressing unit configured to perform a compression process for creating a high-compressed image file from the input image and to control a compression mode of the compression process depending on at least the original type recognized by the original type recognizing unit.

[Object] To prevent an inappropriate processing parameter from being used in a case in which an image that may be expressed by various expression methods is handled.

[Solution] Provided is an image processing device including: a control unit that decides a processing parameter for image processing performed on an image on the basis of at least one of a transfer function related to conversion between light and an image signal that is applied to the image or a color range that is applied to the image; and a processing unit that executes the image processing using the processing parameter that is decided by the control unit.

[Object] To prevent an inappropriate processing parameter from being used in a case in which an image that may be expressed by various expression methods is handled. [Solution] Provided is an image processing device including: a control unit that decides a processing parameter for image processing performed on an image on the basis of at least one of a transfer function related to conversion between light and an image signal that is applied to the image or a color range that is applied to the image; and a processing unit that executes the image processing using the processing parameter that is decided by the control unit.

An image processing apparatus includes a first generation unit and a second generation unit. The first generation unit generates reduced original image data for forming a reduced image of an original image to be formed on the basis of print data. The second generation unit generates background-emphasized reduced image data for forming a reduced image in which a reduced background region is emphasized in the reduced image, and the reduced background region corresponds to a background region of an object included in the original image.