JP5652111B2 - Image processing apparatus and image processing program - Google Patents

Description

  The present invention relates to an image processing apparatus and an image processing program.

  There is known an image processing apparatus that detects a pattern (pattern information) appearing on the surface of a medium and authenticates the originality of the medium based on the pattern information. Specifically, for example, in the following Patent Document 1, the electric signal from the image sensor that optically reads the surface of the medium, converts it into an electric signal, and outputs the electric signal is parallel to the gain adjustment and AD converter of 2. Input and optimize one gain adjustment and AD conversion unit to output a luminance signal optimal for pattern extraction, and display the other gain adjustment and AD conversion unit on the surface of the medium. An image processing apparatus that is optimized to output a luminance signal that is optimal for extraction of the image is disclosed.

Japanese Unexamined Patent Publication No. 2009-5312

  When pattern information is acquired by normal copying or scanning operations, that is, by scanning (normal scanning) of the reading unit for reading images and characters appearing on the surface of the medium, An object of the present invention is to provide an image processing apparatus and an image processing program that do not require scanning of a reading unit.

  According to a first aspect of the present invention, there is provided an image processing device for generating image information by optically reading a surface of a medium, and an image information generating unit on the surface of the medium based on the generated image information. In accordance with the pattern information acquisition means for acquiring the represented pattern information, ground color information acquisition means for acquiring ground color information of the medium based on the generated image information, and the acquired ground color information An operation mode control unit that controls the image information generation unit to operate in the first or second mode, and an amount of information of the pattern information included in the image information generated by the first mode is The operation mode control means has a gray value that is less than a predetermined reference value when the acquired ground color information is smaller than the amount of information of the pattern information included in the image information generated by the second mode. If you have Operates the image information generation means according to the first aspect, and the pattern information acquisition means acquires the pattern information based on the image information generated according to the first aspect. And

  The image processing device according to claim 2 is the image processing device according to claim 1, wherein the operation mode control unit has a gray value that is greater than a predetermined reference value. In the second aspect, the image information generating unit is operated according to the second aspect, and the pattern information acquiring unit acquires the pattern information based on the image information acquired according to the second aspect. Features.

  The image processing apparatus according to claim 3 is the image processing apparatus according to claim 1 or 2, wherein the image information is image information in a device-dependent color space, and the pattern information acquisition unit is configured to depend on the device. The pattern information is acquired from image information in a color space.

The image processing apparatus according to claim 4, the image processing apparatus according to any one of claims 1 to 3, wherein the image information generating means, illumination means, the light amount of the illumination light as evidenced by the illuminating means Illumination light control means for controlling, imaging means for converting reflected light on the surface of the medium irradiated with the illumination light into an electrical signal, and quantization means for quantizing the electrical signal, the illumination light The control means controls the amount of illumination light in the first aspect to be smaller than the amount of illumination light in the second aspect.

The image processing apparatus according to claim 5, in the image processing apparatus according to any one of claims 1 to 3, wherein the image information generating means includes an imaging means for converting an electric signal the light reflected at the surface of the medium A gain adjusting means for adjusting the gain of the imaging means, an offset adjusting means for adjusting the offset of the imaging means, and a quantizing means for quantizing the electrical signal, wherein the gain adjusting means and the offset adjusting means are The gain adjustment value and the offset adjustment value in the first aspect are set to values larger than the gain adjustment value and the offset adjustment value in the second aspect.

The image processing apparatus according to claim 6, in the image processing apparatus according to any one of claims 1 to 3, wherein the image information generating means includes an imaging means for converting an electric signal the light reflected at the surface of the medium A quantization means for quantizing the electrical signal; and an image processing means for performing a process of deleting image information having a gray value equal to or higher than a predetermined reference value from the image information from the quantization means. When the image information generating means is controlled to operate in the second mode, the image information generating means is controlled to output the image information subjected to the processing and operate in the second mode. In this case, the image information from the quantization means is output.

  The image processing program according to claim 7, wherein the pattern information acquisition unit acquires pattern information represented on the surface of the medium based on image information generated by optically reading the surface of the medium, and the generation Based on the obtained image information, the ground color information acquisition means for acquiring the ground color information of the medium, and the image information generation means according to the acquired ground color information in the first or second mode. An image processing program for causing a computer to function as an operation mode control means for controlling operation, wherein the amount of the pattern information included in the image information generated by the first mode is the second Less than the amount of information of the pattern information included in the image information generated according to the mode, the operation mode control means, the gray value of the acquired ground color information is less than a predetermined reference value If it has, the image information generation means is operated according to the first aspect, and the pattern information acquisition means acquires the pattern information based on the image information generated according to the first aspect. It is characterized by that.

  According to the first and seventh aspects of the present invention, the pattern information is obtained by normal copying or scanning operation, that is, scanning of the reading unit (normal scanning) for reading an image or a character appearing on the surface of the medium. If acquired, scanning of the reading unit for acquiring pattern information is not necessary.

  According to the second aspect of the present invention, when there is a low possibility that pattern information can be acquired by normal scanning, the pattern is obtained from image information containing more pattern information than image information generated by the reading unit in the normal mode. Information is acquired.

  According to the third aspect of the present invention, the pattern information is acquired from the image information including more pattern information than when the pattern information is acquired from the image information in the non-device-dependent color space.

  According to the fourth aspect of the present invention, an electric signal including more pattern information than an electric signal generated in the normal mode is input to the quantization means.

  According to the fifth aspect of the present invention, the electric signal including more pattern information than the electric signal generated in the normal mode is electrically adjusted so as to be input to the quantization means.

  According to the sixth aspect of the present invention, when the reading unit is controlled to operate in a manner of acquiring the pattern information, the deletion of the pattern information based on the processing in the image processing unit is prevented.

It is a figure for demonstrating the outline | summary of a structure of the image processing apparatus in embodiment of this invention. It is a figure for demonstrating the structure of the reading part in embodiment of this invention. It is a figure for demonstrating the structure of the reading part and control part in embodiment of this invention. It is a figure which shows the relationship between the value of the luminance signal output from an AD conversion circuit in the normal mode, and the information content of pattern information. It is a figure which shows the relationship between the value of the luminance signal output from an AD conversion circuit, and the information content of pattern information in the pattern information acquisition mode. It is a figure which shows an example of a sampling area | region. It is a figure for demonstrating the flow of the pattern acquisition process in this Embodiment. It is a figure for demonstrating the structure of the reading part in the modification of this invention. It is a figure for demonstrating the relationship between the voltage value which the output electrical signal from an image reading circuit has, and the information content of pattern information.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, about drawing, the same code | symbol is attached | subjected to the same or equivalent element, and the overlapping description is abbreviate | omitted.

  FIG. 1 is a diagram for explaining an outline of a configuration of an image processing apparatus 100 according to an embodiment of the present invention. The image processing apparatus 100 according to the present embodiment is, for example, a multifunction machine having a copy function, a scan function, and the like. As illustrated in FIG. 1, for example, a control unit 101, a storage unit 102, an operation unit 103, a display unit, and the like. 104, a reading unit 105, a printer unit 106, and a communication unit 107. Note that the units 101 to 107 are connected to each other by an internal bus 109.

  The control unit 101 is an MPU, for example, and operates according to a program stored in the storage unit 102. The storage unit 102 is an information recording medium that includes an information recording medium such as a ROM, a RAM, and a hard disk, and holds a program executed by the control unit 101. The storage unit 102 also operates as a work memory for the control unit 101.

  The program may be provided by being downloaded through a network, or may be provided by various information recording media that can be read by a computer such as a CD-ROM or a DVD-ROM. .

  The operation unit 103 includes, for example, an interface such as a plurality of buttons and a touch panel displayed on the display unit 104 described later, and outputs the content of the instruction operation to the control unit 101 in accordance with a user instruction operation. The display unit 104 is, for example, a liquid crystal display, an organic EL display, or the like, and displays information according to an instruction from the control unit 101.

  The printer unit 106 prints, for example, an image acquired by the reading unit 105 or an image stored in the storage unit 102 according to a user instruction. The communication unit 107 connects the image processing apparatus 100 to another image processing apparatus 100A via the network 108.

  The other image processing apparatus 100A may be a multifunction peripheral having the same configuration as the image processing apparatus 100, or may be a so-called personal computer including a CPU, a memory, and the like.

  The reading unit 105 reads an image on the surface of the medium by scanning the surface of the medium moved by the conveyance unit 201 described later with an imaging sensor described later. Specifically, the reading unit 105 reads characters, images, or the like represented on the surface of the medium. At this time, a pattern appearing on the surface of the medium, for example, a pattern of fibers forming the medium, a pattern formed by minute cracks on the surface of the medium, fine particles of the material, or the like is also read. The medium may be a plastic substrate or the like in addition to the original paper.

  Next, the configuration of the reading unit 105 will be described. FIG. 2 is a diagram for explaining the configuration of the reading unit 105. As illustrated in FIG. 2, the reading unit 105 includes a conveyance unit 201, a contact glass 202, first to third mirrors 203 to 205, a lens 206, an image sensor 207, and a light source 208.

  The conveyance unit 201 includes a drawing roller 209, a conveyance roller 210, and a discharge roller 211. For example, the drawing roller 209 moves the medium 212 (for example, original paper) one by one to the conveying roller 210 in accordance with an instruction from the user to the operation unit 103. The conveyance roller 210 moves the medium 212 on the contact glass 202.

  At this time, the surface of the medium 212 is read by the image sensor 207 along the reading line 214. Specifically, the reflected light from the medium 212 is imaged on the image sensor 207 via the first to third mirrors 203 to 205 and the lens 206, so that the image sensor 207 Get an image of the surface.

  Needless to say, the reflected light is reflected light on the surface of the medium 212 of the irradiation light irradiated on the medium 212 from the light source 208. The imaging sensor 207 is, for example, a CCD (Charge Coupled Device) linear sensor formed by linearly arranging light receiving cells (pixels) such as photodiodes.

  Note that the configuration of the reading unit 105 is not limited to the above, and is replaced with a configuration that is substantially the same as the configuration described in the above embodiment, a configuration that exhibits the same effect, or a configuration that can achieve the same purpose. May be. For example, it may be configured to have two imaging sensors and read the surface of the medium 212 with two reading lines. In the above description, the surface of the medium 212 is read while the medium 212 is moving. However, the image sensor 207 may scan the surface of the medium 212 to read the surface of the medium 212.

  Next, the configuration of the reading unit 105 and the control unit 101 will be described. FIG. 3 is a diagram for explaining the configuration of the reading unit 105 and the control unit 101. As shown in FIG. 3, the reading unit 105 and the control unit 101 include an illumination light control circuit 301, an image reading circuit 302, an AD conversion circuit 303, an image processing unit 304, a reading control unit 305, a ground color information acquisition unit 306, a pattern. An information acquisition unit 307, an output unit 308, and a collation unit 309 are included.

  The illumination light control circuit 301 controls, for example, the current supplied to the light source 208 according to the operation mode of the reading unit 105, and controls the amount of illumination light emitted from the light source 208 to the surface of the medium. Note that the operation mode of the reading unit 105 appears, for example, in a normal copy or scanning operation, that is, a normal mode used when reading an image or a character appearing on the surface of the medium and a surface of the medium. It includes a pattern information acquisition mode to read the pattern. Then, in accordance with a control signal from a reading control unit 305 described later, the illumination light control circuit 301 performs control so that the amount of illumination light in the pattern information acquisition mode is smaller than the amount of illumination light in the normal mode. In addition, when noise is increased in the image information by reducing the amount of light, for example, the image processing unit 304 may be configured to perform noise removal processing such as smoothing processing. In this case, for example, the read sensitivity of the medium of the reading unit 105 may be adjusted by adjusting the gain or offset of the image reading circuit 302 of the reading unit 105.

  The image reading circuit 302 includes, for example, an image sensor 207 and an amplifier circuit (not shown). The imaging sensor 207 converts the reflected light of the illumination light from the light source 208 on the surface of the medium into an electric signal (analog signal), and the amplifier circuit amplifies the converted electric signal by the amplifier circuit and performs AD conversion. Output to the circuit 303.

  The AD conversion circuit 303 quantizes the electric signal output from the image reading circuit 302. Specifically, for example, the electric signal is converted into a luminance signal represented by a gradation level of 8 bits (0 to 255).

  Here, the operation of the circuit will be specifically described. FIG. 4 is a diagram illustrating the relationship between the value of the luminance signal output from the AD conversion circuit and the amount of pattern information in the normal mode. FIG. 5 is a diagram showing the relationship between the value of the luminance signal output from the AD conversion circuit and the information amount of the pattern information in the pattern information acquisition mode. 4 and 5, the vertical axis indicates the signal value of the luminance signal (value from 0 to 255), and the horizontal axis indicates the information amount of the pattern information.

  For example, in the luminance signal output in the normal mode, the portion corresponding to the pattern information is, for example, a narrow range (for example, 200-250) of the signal value 0 to 255 of the luminance signal, as shown in FIG. In the range or the like, the luminance signal is normally distributed around the vicinity where the luminance signal has a value corresponding to the ground color of the medium. In the pattern information acquisition mode, the amount of illumination light is controlled to be smaller than the amount of illumination light in the normal mode, and the output electric signal including a larger amount of pattern information is quantized. Therefore, in the pattern information acquisition mode, for example, as shown in FIG. 5, the pattern information is a luminance signal having large irregularities, that is, a wide range of signal values 0 to 255 of the luminance signal, as compared with the case of FIG. 4. (For example, a range of 50 to 250) appears as a luminance signal. In other words, the information amount of pattern information included in the luminance signal in the normal mode is smaller than the information amount of pattern information included in the luminance signal in the pattern information acquisition mode.

  As shown in FIG. 3, the image processing unit 304 performs various image processing. For example, processing for removing so-called fog (for example, dot-like noise) resulting from scanning of the reading unit 105, processing for converting image information having a predetermined luminance value or more into image information in a non-device-dependent color space, For example, enlargement or reduction of image information, color correction, and the like. Note that the image processing may be specified by a user or may be set in advance, for example. The image processing unit 304 may be configured by hardware or may be configured to be processed by software. Furthermore, a part of the processing of the image processing unit 304 may be configured to be processed by hardware, and the other processing may be configured to be processed by software (corresponding to the processing of the control unit 101).

  The reading control unit 305 controls the operation mode of the reading unit 105 in accordance with ground color information from a ground color information acquisition unit 306 described later. Specifically, when the luminance value is equal to or less than a predetermined reference value, the reading unit 105 is operated in the normal mode, while when the luminance value is larger than the predetermined reference value, Control the reading unit 105 to operate in the pattern information acquisition mode. More specifically, in the present embodiment, as described above, the illumination control circuit is controlled so that the amount of illumination light from the light source 208 differs between the pattern information acquisition mode and the normal mode.

  The ground color information acquisition unit 306 acquires the ground color information of the medium based on the image information generated by the reading unit 105. Here, the ground color information is information on a portion corresponding to the ground color (background color) of the medium, that is, a portion of the surface of the medium that does not include characters or images. It is the luminance value (color density value) of the signal. Specifically, for example, the entire medium is pre-scanned by the reading unit 105 (before the original image is read, an operation of reading in advance at a speed faster than the original image reading (corresponding to the normal mode)), and the pre-scan is performed. May be calculated as the luminance value corresponding to the ground color of the medium. Or, for example, the luminance value calculated based on the average value of the luminance values of the luminance signal of a portion where there is no normal image or character (sampling region) such as a corner area of the medium is set as a luminance value corresponding to the ground color of the medium You may get it. In addition, when the ground color information is acquired based on the image information acquired from a partial area (sampling area) 601 at the leading end of the medium as shown in FIG. The acquisition of image information in the information acquisition mode may be performed continuously.

  The pattern information acquisition unit 307 acquires pattern information based on the image information generated by the reading unit 105 in response to an instruction from the reading control unit 305. At this time, the pattern information may be acquired based on the image information in the device-dependent color space including more pattern information than the image information in the non-device-dependent color space.

  The output unit 308 outputs the image information from the reading unit 105 or the acquired pattern information to each unit (for example, the storage unit 102, the printer unit 106, etc.) in accordance with a user operation instruction. For example, if the user instruction is a copy, the image information is output to the printer unit 106, and the printer unit 106 prints the image information. If the user instruction is registration of pattern information, for example, the pattern information is stored in an external database or the like via the storage unit 102 or the network 108.

  For example, when the user's instruction is collation, the collation unit 309 performs collation between the pattern information acquired by the pattern information acquisition unit 307 and the pattern information already registered in the corresponding medium. Information on the originality of the image is displayed on the display unit 104. Specifically, as described in, for example, Japanese Patent No. 4103826, a medium based on whether or not the correlation value between registered pattern information and collation pattern information is greater than or equal to a preset reference value. Confirm the originality of. Note that details of the processing are well known, and thus detailed description thereof is omitted. Also, the pattern information of the corresponding medium is stored in, for example, an external database (not shown) and is acquired via the network 108.

  The collation result is displayed on the display unit 104 as, for example, “original” when collation target medium is collated, or “not original” when it is determined that the medium is not the original. Is displayed. The display of the matching result is not limited to this, and may be displayed with a predetermined symbol such as XX.

  Note that the configurations of the reading unit 105 and the control unit 101 are not limited to the above, but are substantially the same as the configurations described in the above embodiment or the present modification, the configurations that exhibit the same operational effects, or the same. It may be replaced with a configuration capable of achieving the purpose.

  Next, a flow of pattern acquisition processing in the present embodiment will be described. FIG. 7 is a diagram for explaining the flow of pattern acquisition processing in the present embodiment.

  As shown in FIG. 7, the reading unit 105 starts reading scanning for detecting ground color information (S101). The reading scan may be a process of reading the entire medium as described above, or may be a process of reading a predetermined part (sampling area) of the medium. Further, as described above, the reading scan may be performed by moving the medium or by moving the image sensor 207.

  The ground color information acquisition unit 306 acquires the luminance value of the luminance signal of the portion corresponding to the ground color of the medium based on the image information acquired by the reading unit 105 according to the reading scan. (S102).

  When the luminance value is equal to or less than a predetermined reference value, the reading control unit 305 controls the reading unit 105 to operate in the normal mode, and the reading unit 105 acquires image information in the normal mode. (S103).

  The pattern information acquisition unit 307 acquires pattern information based on the image information generated by the reading unit 105 in response to an instruction from the reading control unit 305 (S104). When the pattern information is acquired, the process is terminated.

  On the other hand, when the pattern information cannot be acquired, a signal for notifying the acquisition is transmitted to the reading control unit 305, and the reading control unit 305 causes the reading unit 105 in the pattern information acquisition mode according to the signal. The reading unit 105 controls to operate, and acquires image information again in the pattern information acquisition mode (S105).

  The reading control unit 305 controls the reading unit 105 to operate in the pattern information acquisition mode when the luminance value is larger than a predetermined reference value, and the reading unit 105 performs image information in the pattern information acquisition mode. Is acquired (S105).

  The pattern information acquisition unit 307 acquires pattern information based on the image information acquired in the pattern information acquisition mode (S106). If the pattern information has been acquired, the process ends. On the other hand, if the pattern information cannot be acquired, the process returns to S105 again, and image information is acquired again in the pattern information acquisition mode.

  Note that the flow of processing in acquiring pattern information is not limited to the above flow, and can achieve substantially the same flow, the same operational effect, or the same purpose as the flow shown in the above modification. It may be replaced with a flow that can.

  The present invention is not limited to the above-described embodiment, and is substantially the same configuration as the configuration shown in the above-described embodiment, a configuration that exhibits the same operational effects, or a configuration that can achieve the same purpose. May be replaced.

[Modification]
Next, a modified example of the present invention will be described. In this modification, the configuration of the reading unit 105 is mainly different. Other points are the same as those in the above embodiment, and the description of the same points is omitted.

  FIG. 8 is a diagram for explaining the configuration of the reading unit 105 in the present modification. As illustrated in FIG. 8, the reading unit 105 includes a gain adjustment circuit 801, an offset adjustment circuit 802, an image reading circuit 302, an AD conversion circuit 303, and an image processing unit 304.

  The gain adjustment circuit 801 adjusts the gain of the image reading circuit 302. Specifically, for example, as shown in FIG. 9, in the pattern information acquisition mode, the gain adjustment value used for the gain adjustment is set to have a value larger than that in the normal mode.

  The offset adjustment circuit 802 adjusts the offset of the image reading circuit 302. Specifically, for example, as shown in FIG. 9, in the pattern information acquisition mode, the offset adjustment value used for the offset adjustment is set to have a value larger than that in the normal mode.

  FIG. 9 is a diagram for explaining the relationship between the voltage value of the output electric signal from the image reading circuit 302 and the information amount of the pattern information. The output electrical signal shown in FIG. 9 indicates a state in which neither gain adjustment nor offset adjustment is performed. As shown in FIG. 9, the gain adjustment value and the offset adjustment value in the pattern information acquisition mode include all the pattern information, and have larger values than the gain adjustment value and the offset adjustment value in the normal mode, respectively. Is set. Further, the difference in gain adjustment value between the normal mode and the pattern information acquisition mode is smaller than the difference between offset adjustment values in the normal mode and the pattern information acquisition mode. The gain adjustment value and the offset adjustment value may be designated by the user via the operation unit 103, for example, or may be configured in advance in the gain adjustment circuit 801 or the offset adjustment circuit 802. Or the structure set based on the said acquired ground color information may be sufficient.

  The image reading circuit 302 includes, for example, an image sensor 207 and an amplifier circuit (not shown). The imaging sensor 207 converts the reflected light from the surface of the medium into an electrical signal (analog signal), and the amplifier circuit amplifies the converted electrical signal by the amplifier circuit and outputs the amplified signal to the AD converter circuit 303. At this time, the amplification circuit is adjusted in gain and offset by the gain adjustment circuit 801 and the offset adjustment circuit 802. In the above description, the amplification circuit is configured to adjust the gain and offset. However, the imaging sensor 207 may be configured to adjust the gain and offset directly.

  The AD conversion circuit 303 quantizes the electric signal output from the image reading circuit 302. Specifically, for example, the electric signal is converted into a luminance signal represented by a gradation level of 8 bits (0 to 255). At this time, the electric signal is output from the image reading circuit 302 that has been gain-adjusted and offset-adjusted according to whether it is the normal mode or the pattern information acquisition mode as described above, and the electric signal is converted into a luminance signal. Specifically, the gain and offset are adjusted so that the information amount of the pattern information included in the luminance signal in the pattern information acquisition mode is larger than the information amount of the pattern information included in the luminance signal in the normal mode.

  The present invention is not limited to the above-described embodiment or modification, and achieves substantially the same configuration, the same operational effect, or the same object as the configuration shown in the above-described embodiment. It may be replaced with a configuration capable of. For example, the reading control unit 305 may be configured so that the processing of the image processing unit 304 of the reading unit 105 is different in the pattern information acquisition mode and the normal mode. Specifically, for example, in the normal mode, the process for removing the dot-shaped noise described above is performed, but in the pattern information acquisition mode, the image processing unit 304 may not perform the process. The image information generation unit described in the claims corresponds to, for example, the reading unit 105, and the operation mode control unit corresponds to, for example, the reading control unit 305.

  100, 100A image processing apparatus, 101 control unit, 102 storage unit, 103 operation unit, 104 display unit, 105 reading unit, 106 printer unit, 107 communication unit, 108 network, 109 internal bus, 201 transport unit, 202 contact glass, 203 to 205 First to third mirrors, 206 lenses, 207 imaging sensors, 208 light sources, 209 pull-in rollers, 210 transport rollers, 211 discharge rollers, 212 media, 214 reading lines, 301 illumination light control circuits, 302 image reading circuits , 303 AD conversion circuit, 304 image processing unit, 305 reading control unit, 306 ground color information acquisition unit, 307 pattern information acquisition unit, 308 output unit, 309 collation unit, 601 region (sampling region), 801 gain adjustment circuit, 802Offset adjustment circuit.

Claims (7)

Image information generating means for generating image information by optically reading the surface of the medium;
Pattern information acquisition means for acquiring pattern information represented on the surface of the medium based on the generated image information;
Ground color information acquisition means for acquiring ground color information of the medium based on the generated image information;
Operation mode control means for controlling the image information generation means to operate in the first mode or the second mode according to the acquired ground color information,
The information amount of the pattern information included in the image information generated by the first aspect is smaller than the information amount of the pattern information included in the image information generated by the second aspect,
The operation mode control unit operates the image information generation unit according to the first mode when the acquired ground color information has a gray value equal to or less than a predetermined reference value.
The pattern information acquisition means acquires the pattern information based on the image information generated according to the first aspect.
An image processing apparatus. The operation mode control unit operates the image information generation unit according to the second mode when the acquired ground color information has a gray value larger than a predetermined reference value.
The pattern information acquisition means acquires the pattern information based on the image information acquired according to the second aspect.
The image processing apparatus according to claim 1. The image information is image information in a device-dependent color space,
The image processing apparatus according to claim 1, wherein the pattern information acquisition unit acquires the pattern information from image information in the device-dependent color space. The image information generating means
Lighting means;
Illumination light control means for controlling the amount of illumination light illuminated by the illumination means;
Imaging means for converting reflected light on the surface of the medium irradiated by the illumination light into an electrical signal;
Quantizing means for quantizing the electrical signal,
The illumination light control means, the light amount of the illumination light in the second aspect, in any one of claims 1 to 3, wherein the controller controls to less than the amount of illumination light in the first embodiment The image processing apparatus described. The image information generating means
Imaging means for converting reflected light on the surface of the medium into an electrical signal;
Gain adjusting means for adjusting the gain of the imaging means;
Offset adjusting means for adjusting the offset of the imaging means;
Quantizing means for quantizing the electrical signal,
The gain adjustment means and the offset adjustment means set the gain adjustment value and the offset adjustment value in the second aspect to values larger than the gain adjustment value and the offset adjustment value in the first aspect. The image processing apparatus according to claim 1. The image information generating means
Imaging means for converting reflected light on the surface of the medium into an electrical signal;
Quantization means for quantizing the electrical signal;
Wherein the image processing means for performing image processing on the image information from said quantization means,
When the image information generation unit is controlled to operate in the first mode, the image information generation unit outputs the image information subjected to the processing and is controlled to operate in the second mode. The image processing apparatus according to claim 1, wherein the image information from the quantization unit is output. Pattern information acquisition means for acquiring pattern information represented on the surface of the medium based on image information generated by optically reading the surface of the medium;
Ground color information acquisition means for acquiring ground color information of the medium based on the generated image information; and
An operation mode control unit configured to control an image information generation unit that generates image information by optically reading the surface of the medium according to the acquired ground color information to operate in the first or second mode; An image processing program for causing a computer to function as
The information amount of the pattern information included in the image information generated by the first aspect is smaller than the information amount of the pattern information included in the image information generated by the second aspect,
The operation mode control unit operates the image information generation unit according to the first mode when the acquired ground color information has a gray value equal to or less than a predetermined reference value.
The pattern information acquisition means acquires the pattern information based on the image information generated according to the first aspect.
An image processing program characterized by that.

Images