Abstract: An optical sheet has an isotropic medium layer and an anisotropic medium layer. The isotropic medium layer is made of an optically isotropic medium and has a first surface and ridge-shaped projections. The projections are formed on the first surface, arranged in a first direction and extend in a second direction intersecting at right angles to the first direction. Each projection has a cross section shaped like a segment of a circle. The anisotropic medium layer is made of an optically uniaxial medium and has a second surface and groove-shaped recesses. The recesses are made in the second surface, arranged in the first direction and extend in the second direction. Each recesses has a cross section shaped like a segment of a circle. The isotropic and the anisotropic medium layers are laid one on the other, with the respective projections firmly fitted in the respective recesses.

Abstract: A liquid crystal display (LCD) includes a panel including a first substrate on which a black matrix, a conductive layer, an insulation layer, and a common electrode are formed, a second substrate formed opposite to the first substrate and coupled to the first substrate by a sealant, and a liquid crystal between the first and second substrates. A temperature sensor senses a temperature of the panel and/or an environment surrounding the panel. A power supply controls the temperature of the panel by heating the conductive layer in response to the temperature sensed by the temperature sensor.

Abstract: A fabricating method of an array substrate for a transflective liquid crystal display device includes: sequentially depositing a first metal layer and an impurity-doped amorphous silicon layer on a substrate and etching the first metal layer and the impurity-doped amorphous silicon layer through a first mask process to form source and drain electrodes, a data line and an ohmic contact layer. An amorphous silicon layer, a first insulating layer and a second metal layer are sequentially deposited on the source and drain electrodes, the data line and the ohmic contact layer and etching the amorphous silicon layer, the first insulating layer and the second metal layer through a second mask process to form a gate electrode, a gate line and an active layer, the gate line defining a pixel region with the data line. A second insulating layer is formed on the gate electrode and the gate line.

Abstract: A repairing device for a display device includes a substrate and a color filter disposed on the substrate. The color filter includes a first surface facing the substrate and a second surface disposed opposite to the first surface. The repairing device includes laser equipment illuminating a laser beam focused on the first surface and having a wavelength of greater than about 250 nm.

Abstract: A lithographic apparatus includes a patterning device for patterning a beam of radiation, a projection system for projecting the patterned beam of radiation onto a substrate, a gas purged sealing aperture extending between different zones of the apparatus, and a gas supply arrangement for supplying a mixture of at least argon and hydrogen to the sealing aperture.

Abstract: Calibration of spot height offsets in a level sensor is performed on a resist-coated substrate to eliminate process dependencies of substrate position measurements obtained by the level sensor.

Abstract: The invention is directed to a method for performing a tilted focus test that includes providing a target object, providing a projection beam of radiation using a radiation source, providing at least one reflective device to produce a projected projection beam of radiation onto the target portion, and producing a first projected projection beam of radiation onto the target object using the at least one reflective device in a first orientation. The invention further includes using a tilting device for tilting the at least one reflective device to a second orientation to provide a second projection beam with a tilt relative to said first projection beam, producing a second projected projection beam of radiation onto the target object, determining a lateral shift of the first and second projected projection beams on the target object, and determining from said lateral shift a defocus of the target object with respect to the projected projection beam.

Abstract: With respect to each of a plurality of shots on a substrate, a line or surface is calculated which approximates a plurality of positions of the surface of the substrate detected by a detector with respect to a plurality of places, and the difference between the position of the surface detected by the detector and the position of the line or surface in the direction of the optical axis of a projection optical system is calculated with respect to each of the plurality of places. With respect to each of the plurality of places, the differences are averaged over the plurality of shots to determine an offset value.

Abstract: The method and the apparatus measures the total spectral radiance factor Bxs (?) of a fluorescent sample illuminated by a specified illumination for testing Is without a fluorescent standard and a bothersome UV correction using it. The method and the apparatus calculates Bxs(?) based on the spectral intensity Is(?) of the illumination for testing, the measured spectral intensities I1(?) and I2(?) of actual illuminations I1 and I2 which are different from each other, a bi-spectral luminescent radiance factor F(?,?) or a bi-spectral radiance factor B(?,?) which is close to either of the sample, and the measured spectral intensities Sx1 (?) and Sx2(?) of the light emitted from the sample illuminated by illuminations I1 and I2.

Abstract: In three-dimensional measurement where circular polarized light or elliptical polarized light is projected as measurement light, correct measurement results can be obtained irrespective of the difference in intensity between primary reflected light and secondary reflected light.

Abstract: Scatterometers and methods of using scatterometry to determine several parameters of periodic microstructures, pseudo-periodic structures, and other very small structures having features sizes as small as 100 nm or less. Several specific embodiments of the present invention are particularly useful in the semiconductor industry to determine the width, depth, line edge roughness, wall angle, film thickness, and many other parameters of the features formed in microprocessors, memory devices, and other semiconductor devices. The scatterometers and methods of the invention, however, are not limited to semiconductor applications and can be applied equally well in other applications.

Abstract: A system and method for imaging the characteristics of an object (2) having at least a first (2a) and a second (2b) layer. The object (2) is illuminated by means of incident light (4), and light (5b) reflected from the object (2) is detected by means of an imaging sensor (6) in which the detected light is converted into electrical charges, according to which a representation of the object (2) is created. Information on light scattered (5a) in the first layer (2a) and the second layer (2b) of the object (2) is obtained from the representation and this information is compared to stored information in order to detect defects on the object (2).

Abstract: A metrology tool is arranged to measure a parameter of a substrate that has been provided with a pattern in a lithographic apparatus. The metrology tool includes a base frame, a substrate table constructed and arranged to hold the substrate, at least one sensor constructed and arranged to measure a parameter of the substrate, a displacement system to displace one of the substrate table and sensor with respect to the other one of the substrate table and sensor in at least a first direction, a first balance mass, and a first bearing which movably supports the first balance mass so as to be substantially free to translate in the opposite direction of the first direction in order to counteract a displacement of the one of the substrate table and sensor in the first direction.

Abstract: The present invention provides a probe beam profile—modulated optical reflectivity metrology system having a modulated pump source for exciting the sample. A separate probe beam is directed to interact with the sample in a manner so that the rays within the probe beam create a spread of angles of incidence. A detector array simultaneously measures intensities of the rays within the reflected/diffracted probe beam simultaneously at different angles of incidence. The intensity and angle of incidence information is used to analyze the sample.

Abstract: An apparatus for generating a Raman signal of a test sample is disclosed. The apparatus includes a first optical path, a second optical path, a first station, and a second station. The first optical path is adapted for coupling with a radiation source that produces a test beam at the first optical path. The first station is responsive to the test beam and is adapted to house a test standard. The second station is responsive to the test beam and is adapted to house the test sample. In response to the test beam, Raman radiation from the test standard and the test sample are combined and directed to the second optical path, which is adapted for coupling with a spectrometer and a detector for producing a Raman spectrum of the test sample.

Abstract: A surface enhanced Raman scatter (SERS) analyte analyzer. The analyzer has floating surfaces for enhancement of the Raman scattered light from sample molecules. An injector may provide a spray of charged nanoparticles suspended in droplets of an evaporable solution into a chamber. When the solution quickly evaporates, droplets of nanoparticles are left without a supporting solution. These droplets or cloud of charged nanoparticles may then explode into a dispersion or aerosol. The charged nanoparticles may attract molecules of a sample for attachment to their surfaces. A laser light may impinge the attached molecules which may result in surface enhanced Raman scattered light received by a detector or a light spectrometer. Wavelength signatures may then be obtained from the spectrometer. The signatures may provide information about the molecules.

Abstract: A system and the method for transport of microscopic objects/particles involving the use of laser source operatively connected to a microscope objective which is adapted to generate optical focal spots on said particle(s) with asymmetric intensity profile in transverse plane followed by varying the said asymmetry of the gradient optical forces on the micron sized object/particles to thereby transport the microscopic object(s). The system and the method can be used to transport microscopic objects including i) transportation of cells and intra-cellular organelles, ii) acceleration of microscopic objects along any direction in a plane transverse to the direction of propagation of laser beam, iii) optical channeling of objects through a micro-capillary from one micro-well to another and transfer to another channel after desired processing, iv) sorting of microscopic objects, v) optical control of micro-machines, micro-fluidic devices etc.

Abstract: The invention is directed to an arrangement for detecting coatings which are arranged on surfaces of structural component parts or objects and for determining the chemical characteristics and surface properties of these coatings. It comprises a light source for illuminating the coating to be analyzed on the surface of the structural component part and means for imaging the light source on an entrance slit over the surface of the coating to be analyzed. The entrance slit is imaged in a wavelength-dependent manner on a two-dimensional detector unit by a grating. An evaluating unit which is electrically connected to the detector unit serves to evaluate and process the signals supplied by the exposed detector elements of the detector unit.

Abstract: An optical spectrometer having a multi-wafer structure. The structure may be fabricated with MEMS technology. The spectrometer may be integrated with a fluid analyzer. A reflective grating such as a diffraction or holographic grating situated on the circumference of a Rowland circle along with a point of light emission and a detector may be a configuration of the spectrometer. Some configurations may use an external light source where the light may be optically conveyed to the point of emission on the circle. There may be a Raman configuration where an interaction of light with a sample or an interactive film of a channel in a fluid analyzer is the point of light emission for the spectrometer. In some configurations of the spectrometer, the grating and/or the film may be reflective or transmissive.

Abstract: A device is illustrated for detecting particles in a fluid that can detect smaller particles without the need for added power or space and can be implemented inexpensively. The device utilizes two mirrors and a photo-diode. The housing of the photo-electric diode is machined to form one of the mirrors. The mirrors have a special positioning so that the second mirror uses the first mirror to reflect light deflected by particles back to the photo-electric diode.

Abstract: A differential method has been developed which determines displacement from the midpoint of optical transmission (±45°) and utilizes the coupled nature of the two signals for common mode noise rejection to enhance the detection of chiral species. A beam of light is modulated, applied to the chiral mixture, and then split into a first beam and a related orthogonal beam by a polarizer or prism. The first beam and orthogonal beam are converted into electrical signals before a differential comparison of the signals is performed to detect a desired chiral species within the chiral mixture.

Abstract: A hand-held colorimetric device (101) suitable for use by blind or color-blind individuals to determine the color of a surface-under-test (SUT), for example of a fabric, has an aperture (110) which, in use, is covered by the SUT (113) whose color is to be determined. Six LEDs (115A, 115B, 116B, 117A and 117B) arranged in pairs (115A/115B, 116A/116 B, 117a/117B) emitting red/orange, green, and blue light illuminate the SUT and diffuse reflections therefrom containing red/orange, green, and blue spectrum sample values are used to determine the luminous reflectivity and chromaticity values for the color of the SUT. The measured values are compared with colorimetric values of reference surfaces to determine the color of the SUT. The colorimetric device may output the name of the color aurally.

Abstract: An automated seed sampler includes a sampling station; a sampler for removing material from a seed in the sampling station; a seed conveyer for conveying the seed from the sampling station to a compartment in a seed tray; and a conveyor for conveying the material removed from the seed to a corresponding compartment in a sample tray. The method of the present invention comprises feeding seeds individually to a sampling station, removing a sample from the seed in the sampling station; conveying the sample to a compartment in a sample tray, and conveying the seed to a corresponding compartment in a seed tray. The samples can be tested, and the seeds can be sorted according to the results of the testing of their corresponding samples.

Abstract: An apparatus and method provide measurement of a constituent of a fluid, such as ozone in ozonated water. The apparatus includes a vessel to contain the fluid, a light source configured to direct a first band of light and a second band of light along a substantially shared path though the fluid, and a photosensor that senses the first band of light and the second band of light. The constituent has a greater absorption associated with the first band of light than with the second band of light. The method includes modification of a measured attribute of the component in response to the sensed second band of light to improve the accuracy of the measured attribute.

Abstract: A method and apparatus architecture for detecting gases, particularly hazardous gases which should be detected in miniscule amounts. High sensitivity detection of chemical warfare agents (CWAs) is set forth with very low probability of false positives (PFP) by the use of an innovative laser-photoacoustic spectrometer (L-PAS). Detection of diisopropyl methylphosphonate (DIMP), a decomposition product of Sarin and a relatively harmless surrogate for the nerve gases, is made in the presence of other gases that are expected to be interferences in an urban setting. Detection sensitivity for DIMP in the presence of these interferences of better than 0.45 ppb, which satisfies current homeland and military security requirements is shown as well as the first analysis of optical techniques for the detection of chemical warfare agents (CWAs) and toxic industrial chemicals (TICs) in real world conditions.

Abstract: Methods for measuring optical density are described. The color on an area is determined. Based on the color, at least a first illumination source is selected. The area is illuminated with the selected illumination source. Radiation is received from the area, and the received radiation is converted to a signal indicative of optical density.

Abstract: An interferometer includes a beamsplitter, and a compensator. At least one surface of the beamsplitter or compensator has a non-zero power. In one embodiment, one surface of the beamsplitter is flat and the other surface of the beamsplitter is curved. In another embodiment, the interferometer includes a beamsplitter and a compensator, each having at least one surface of non-zero power, and the non-zero power of the beamsplitter and the non-zero power of the compensator are equal to each other.

Abstract: A photo-thermal interferometric spectroscopy system is disclosed that provides information about a chemical at a remote location. A first light source assembly is included that emits a first beam. The first beam has one or more wavelengths that interact with the chemical and change a refractive index of the chemical. A second laser produces a second beam. The second beam interacts with the chemical resulting in a third beam with a phase change that corresponds with the change of the refractive index of the chemical. A detector system is positioned remote from the chemical to receive at least a portion of the third beam. An adaptive optics system at least partially compensates the light beam degradation caused by atmospheric turbulence.

Abstract: Reflectance systems and methods are described that use information of an intermediate reference signal to continuously monitor, detect and/or compensate for drift in a metrology system. The intermediate reference signal is present regardless of whether a sample is being measured. The reflectance system comprises components including a transmission element coupled to a sample area and a receiver. The transmission element is configured to route signals between components of the system. The signals include an illumination signal, and a sample signal resulting from interaction of the illumination signal with a sample when the sample is present in the sample area. The signals also include the reference signal that results from interaction of the illumination signal with one or more components of the system.

Abstract: The invention relates to an apparatus for multiplexing Fiber Optic Interferometric Sensors (FOISs), which apparatus comprises means (1) forming the an optical source for providing m*n distinct wavelengths ?11, ?12, . . . , ?1n, ?21, ?22, . . . , ?2n, . . . , ?m1, ?m2, . . . , ?mn, the optical source including means for generating m groups (111, 112, . . . , 11m) of light pulses, each group 11j (1?j?m) being made up of n light pulses Pk(?j1), Pk(?j2), . . . , Pk(?jn) of distinct wavelengths ?j1, ?j2, . . . , ?jn, the n light pulses Pk(?j1), Pk(?j2), . . . , Pk(?jn) being time delayed one from another, Fiber Optic Interferometric Sensors distributed in m groups (51, 52, . . .

Abstract: This invention is a device for measuring of absolute distances by means of low coherence optical interferometry. The proposed apparatus eliminates thermal of the conventional fiber optic interferometers caused by variation of the refractive index of the optical fiber material to change of the temperature.

Abstract: An ultra-miniature interferometric fiber-optic encoder readhead for sensing displacement of a very fine pitch scale grating is disclosed. The readhead includes a source grating that diffracts diverging source light into +/? 1st order beams, a pair of mirrors that reflect the +/? 1st order beams to converge toward the scale grating. The +/? 1st order scale light beams are reflectively diffracted back from scale grating to return to the mirrors, and are then reflected to converge back toward the light source and a set of adjacent fiber-optic receiver channels. An interference field generating grating positioned in front of the receiver channels produces interference fringes having a desired pitch. Movement of the interference fringes is sensed by the fiber-optic receiver channels to provide displacement information. The readhead may be configured so that primarily or only +/? 1st order light reaches the receiver channels.

Abstract: Output light from an optical cavity includes, for each of a set of modes, an intensity function, and a mode's intensity function includes information, such as about an optical characteristic of an analyte or of a region. For example, the intensity function can include a peak, and its central energy, maximum intensity, contrast, or intermediate intensity width (e.g. FWHM) can indicate the optical characteristic. The output light can be photosensed, providing electrical signals that depend on the optical characteristic. Information about the analyte or region can then be obtained using the electrical signals. For example, the information can be about both refractive index and absorption of an analyte. Cavity-only absorption values, independent, for example, of absorption outside the cavity and of inhomogeneous illumination, can be obtained based on contrast or intermediate intensity width. For detection of glucose in bodily fluid, derivatives of absorption can be obtained.

Abstract: The wheel and tire assembly for running on ground includes measurement means carried by the wheel for measuring topological parameters of the inside surface of a pertinent portion of the tire. These measurement means comprise lighting and viewing means for lighting and viewing a calibrated surface pattern that is subjected to the deformation of the inside surface of the pertinent portion of the tire. The viewing means are preferably of the stereovision type or of the structured light type.

Abstract: A measuring apparatus of this invention comprises: a projector; a camera; a generator that generates, from a photographed image of a fringe pattern projected by the projector at a time of calibration onto each of surfaces, first tuples, each including coordinates of a point on a light receiving plane (LRP) of the camera, light intensity of the point and the height of the surface; a converter that converts the light intensity to a phase angle of the projected fringe pattern (PFP), and generates second tuples, each including the coordinates of the point on the LRP, the phase angle and the height of the surface; a hypersurface generator that generates data representing a tensor product type composite hypersurface (TPTCH) from data of the second tuples; an extractor that extracts data of third tuples, each including coordinates of a point on the LRP and light intensity from a photographed image of a fringe pattern projected by the projector at a time of measurement onto an object to be measured; a second converte

Abstract: A system for tracking the spatial position/motion of an article conveyed along a feed path. The system comprises a reflective surface disposed along the feed path of the article and an optical scanning device disposed remotely from the reflective surface such that the moving article is interposed therebetween. The optical scanning device is operative to (i) transmit light energy along a length of the reflective surface, (ii) receive light energy returned from the reflective surface and (iii) determine the spatial position of the article based upon a condition of the optical path, i.e., whether the optical path is present or interrupted. A break in the optical path is sensed by the optical scanning device and interpreted by the signal processor to determine the spatial position/motion of the moving article.

Abstract: According to one aspect of the invention, there is provided a sensor device which is capable of detecting a state of a movable stage using an easily manufacturable reference grating and capable of improving the accuracy of detection. The sensor device comprises a reference grating which has a configuration that is varied periodically in a two-dimensional direction. A light source emits light to the reference grating. A spectral unit has a plurality of openings to convert the light emitted by the light source into a plurality of light beams through the plurality of openings. A detector unit has a photodetector to receive collectively reflected light beams reflected by the reference grating. The detector unit is provided to detect a state of a movable body relative to the reference grating based on a change of the reflected light beams received by the photodetector.

Abstract: There are difficulties with regard to observing a rotating component in an obscuring environment such as typical of a gas turbine engine where there may be soot, flames, light signals and moisture. It will be understood that simply increasing the light intensity will increase scatter and therefore may “blind” a camera in terms of viewing distinctive features and targets within a rotating component. The present arrangement provides a mirror with an aperture such that an illuminating light source is directed towards a rotating component such that reflection is similarly incident upon the reflective mirror and light deflected to the camera. In such circumstances the camera is less susceptible to light scatter obscuration.

Abstract: An image transmission apparatus capable of carrying out efficient image processing and transmission as a whole even where multiple image transmission requests exist, without increasing the complexity of the apparatus construction. The image transmission apparatus is provided with multiple task processors that are respectively responsible for executing one or more of the image processing operations, a designating unit that designates the image processing operation(s) to be performed, a controller that, where multiple recipients are specified with regard to the image data and different image processing operations are specified for the different recipients, controls each task processor such that the nth operation is executed in common for the recipients for which all operations up to the nth operation are identical, and a transmission unit that transmits to the specified recipients image data that has undergone all of the image processing operations.

Abstract: In a host computer connected to a printer, a determination is made as to whether data should be transmitted to the printer in a printer language or expanded into bit map image data before transmission, and the data in the printer language, or the expanded bit map image data, is transmitted to the printer. The determination of whether to transmit data in a printer language or expand into a bit map image before transmission is made based on an estimate of the time required for expansion by both the printer and by the host computer. If the printer can expand a first page of data into a bit map image in parallel with expansion by the host computer of a second page of data into bit map data, then the first page of data is transmitted in the printer language and the second page of data is expanded into pit map image data before transmission.

Abstract: A digital multifunction device is provided with a RAM having a virtual drive area. A persona computer is connected to the digital multifunction device and is capable of communicating therewith via USB interface. The digital multifunction device enables a personal computer to recognize this virtual drive area as an external storage device, and the personal computer can access to the virtual drive area. Upon receipt of facsimile data, the digital multifunction device converts one page worth data to image data of PDF or TIFF format each time the one page worth data is received. After full page worth data have been received and the converted PDT or TIFF image data are put together in a single data file, the data file is written to the virtual drive area.

Abstract: A facsimile apparatus is disclosed that performs accurate and efficient facsimile transmission while obtaining accurate reception capacity information of each transmission destination. The reception capacity of each transmission destination is stored, together with the mail address, in a memory unit of the apparatus. When facsimile transmission accompanied by a delivery confirmation request is carried out, a main controlling unit causes the memory unit to store the transmission mode. If delivery confirmation mail from the transmission destination contains reception capacity information, the main controlling unit causes the memory unit to store it as the reception capacity information of the transmission destination. If the delivery confirmation mail does not contain reception capacity information but confirms that the communication has been properly completed, the transmission mode already stored in the memory unit is stored as a transmission enabling mode of the transmission destination in the memory unit.

Abstract: An image uploaded from a camera-equipped cellular phone, and additional information attached to the image such as voice information and the like are managed in a database in a service server. Then, an URL for accessing the additional information is issued and converted into a QR code. Order information including the image and the QR code are sent to the print device, and a photo print having the image and the QR code printed on a print paper is produced. When the camera-equipped cellular phone reads the QR code on the photo print and accesses by use of the URL acquired by decrypting the above described QR code, the managed additional information on the image is read from the database correspondingly to the URL, and sent to the camera-equipped cellular phone which has accessed.

Abstract: A client network interface card performs a capability information inquiry to other devices on the network. Virtual device information, which has increased functions over the original capabilities of own device, is disclosed to a PC, based on capability information obtained from other devices. The PC transmits printing data to the client network interface card and commissions printing, based on the virtual printer information. The client network interface card which has received a printing commission exceeding the original capabilities of own device determines a server device to commission the processing to, based on the capability information. Then, processing is commissioned to the server device, and printing data following processing is received and printing output is performed.

Abstract: Methods, apparatus, software, and systems of the present invention allow for optimization of color and shades of gray documents prior to their conversion to a monochrome format. If color/gray elements are identified in the document, the distance between them and their intensity is determined. If there are elements with the same or similar intensity in close proximity to each other, colors of some of the elements may be replaced with solid monochrome colors, and/or dithered surfaces, and/or monochrome patterns. Further, the elements may be outlined. These improvements make elements in the document more distinguishable after its conversion to a monochrome format. The described color optimization and outlining may have wide applicability in the Internet Fax technology.

Abstract: A digital copying machine comprising an image scanner part for reading an original image to reproduce image data of the original image, a laser printer part for printing an image according to given image data, a removable memory card, and a reader/writer of the memory card is provided. For offline print, the image data of a document prepared in an external computer and output control data are stored into the memory card. By installing this memory card in the digital copying machine, the digital copying machine prints the image data read out from the memory card offline in a desired output form. For offline image input, read control data obtained by using an image scanner such as a read gradation level, a read size, density, and the degree of edge enhancement is stored in the removable memory card using software executed in an external computer.

Abstract: A method using a printing system comprising a controller programmed for rendering imposed documents given media cost considerations is described. The method includes steps of: evaluating a print job; evaluate media loaded within printer; and determining media print options including cost. Additionally, embodiments enable user selection of printing option prior to the printing system or rendering the print job or selecting a printing option based on user profile. The print job is then rendered.

Abstract: A method of one embodiment of the invention is disclosed that determines to output an output pixel for a color component of an image pixel. In response to determining to output the output pixel for the color component of the image pixel, the method outputs this output pixel, and spaces out the output of output pixels for other color components of the image pixel.

Abstract: An image forming apparatus includes a first processing unit and a second processing unit. The first processing unit receives multi-valued first compressed image data in accordance with a first compression format that is a variable length compression format. The first compressed image data are externally transferred to the first processing unit. The first processing unit then converts the first compressed image data into second compressed image data in accordance with a second compression format. The second processing unit performs expansion and binarization processes on the second compressed image data, and outputs the second compressed image data to a printer engine.

Abstract: An error adding step adds together input multi-tone image data and peripheral error information. An adding/subtracting step adds to or subtracts from multi-tone image data calculated by the error adding step, a random number in a matrix prepared for each set of pixels of the input multi-tone image data. A quantizing step quantizes multi-tone image data calculated by the adding/subtracting step into image data, the number of bits of which image data being smaller than the number of bits of the multi-tone image data calculated by the adding/subtracting step. An error calculating step calculates an error based on the multi-tone image data calculated by the error adding step and the image data quantized by the quantizing step. An error storing step stores the error calculated by the error calculating step for each peripheral pixel.