Image processing device, program, and information terminal

Abstract

To provide a more user-friendly image processing device that, even if a range of colors in a colored image that is desired to be made invisible is expanded, eliminates the loss of color information in the image and makes it difficult to leave a part unerased, while maintaining the superiority of a virtual sheet.SOLUTION: An image processing device includes: a processing target designation unit 5 that designates a processing target by overlaying a designation color sheet 8 on a range to which invisible processing is applied of a note image N on a display unit 4, a hue designation unit 6 that designates a range of a target color (designated color) to be made invisible by hue, and control means 7 for controlling these memory unit 2, display unit 4, processing target designation unit 5, and hue designation unit 6. The control means 7 is configured including a colored image recognition unit 71 that recognizes a colored image in the note image N within the processing target, a hue determination unit 72 that determines whether or not the hue of the colored image belongs to the hue range designated by the hue designation unit 6, and an image processing unit 73 that performs processing to make the colored image invisible if it is determined that the colored image belongs to the hue range.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an image processing apparatus, a program, and an information terminal having a function of switching the visibility state of characters written in a specific color or a portion where a marker of a specific color is drawn. and It relates to an information terminal.

Background Art

[0002] Conventionally, when learning using documents such as notebooks and reference books, a so-called red sheet, which is a sheet for memorization, is generally used.

[0003] For example, when learning history or English, this red sheet is used by writing specific strings to be memorized in a document with a red pen and covering it with a red sheet of the same color from above, thereby assimilating the red pen part to the color of the sheet to make it invisible. After filling in the blanks with the strings and then removing the red sheet for re-display, efficient memorization learning can be performed.

[0004] Alternatively, a method is also used where a green marker is attached to a specific string to be memorized in a string, and the marker part is painted black and made invisible by covering it with a red sheet having a complementary color relationship from above.

[0005] However, since the red sheet is dark, the overall brightness decreases, making it difficult to view the entire document. Also, even after removing the red sheet, since the color of the marker is dark, it is difficult to read the string below it.

[0006] On the other hand, an application that realizes the function of such a red sheet used in the real world in a virtual space has been proposed (for example, Non-Patent Document 1).

[0007] This app displays a note image on the screen and, by overlaying a sheet equivalent to a red sheet onto the note image, it converts a specific color in the colored image at that location to white, making it invisible. It also has a function that extracts text from an image, places a marker on the part of the extracted text area that has a specific color, and makes the text underneath invisible by making the marker opaque.

[0008] According to this, although it does not have a function to make text invisible using complementary colors, it can achieve virtually the same function as a real red sheet in terms of making text invisible. Furthermore, it does not require linking the color of the colored image to be invisible with the color of the sheet, and it does not require using markers or sheets that are so dark that the text underneath becomes difficult to read. As a result, it has advantages such as improved color selection and visibility compared to a real red sheet. [Prior art documents] [Patent Documents]

[0009] [Non-Patent Document 1] https: / / www.myfamily.place / ea-doc / doku.php?id=memorize_filtertype#%E8%B5%A4%E8%89%B2firutano%E7%A8%AE%E9%A1%9E [Overview of the project] [Problems that the invention aims to solve]

[0010] However, the former function converts the entire image to monochrome and identifies and processes objects to be invisible based on their brightness. As a result, surrounding images that are not targeted also become monochrome, leading to a decrease in image quality and making them difficult to see. Additionally, when removing colored text, the process involves changing the colored text to white text to make it invisible. However, if the background is not white but, for example, gray, the white text stands out against the background and can still be read, which is a bug.

[0011] On the other hand, the latter function does not convert a color image to a monochrome image, but rather pinpoints and makes only specific colors within the color image invisible, thus preserving the surrounding color information. However, the target colors are extremely limited and narrow, and there are issues with accuracy, such as the possibility of missing some red if, for example, the system detects a slight difference in color and determines it is a mismatch.

[0012] This invention addresses these challenges and provides a more user-friendly image processing device and program that, while maintaining the advantages of a virtual sheet over a real red sheet, eliminates the loss of color information in an image even when expanding the range of colors in a colored image that should be made invisible, and also reduces the likelihood of areas being left unerased. and The goal is to create an information terminal. [Means for solving the problem]

[0013] To achieve this objective, the present invention employs the following means.

[0014] In other words, the image processing apparatus according to the present invention comprises a storage unit for storing document images, a display unit for displaying document images stored in the storage unit, a processing target designation unit for specifying a processing target by overlaying a sheet over a range of the document image on the display unit to be made invisible, a hue designation unit for specifying a range of hue for the target color to be made invisible, and control means for controlling the storage unit, display unit, range designation unit, and hue designation unit, wherein the control means includes a colored image recognition unit for recognizing colored images in the document image within the processing target, a hue determination unit for determining whether the hue of the colored image belongs to the hue range specified in the hue designation unit, and an image processing unit for performing processing to make the colored image invisible if it is determined to belong to the hue range. premise Here, a document image refers to a document (a document containing text) such as a notebook or reference book that has been converted into an image.

[0015] By doing so, image processing is performed on the colored image belonging to the specified hue range, while image processing is not performed on the colored image not belonging to the specified hue range. Therefore, the original color is not damaged and the information of the original image around can be retained. Moreover, if a certain hue such as a warm color system or a cool color system is specified in advance, the problem that omission occurs due to a slight color difference can be solved.

[0016] At that time, In order to enable display / non-display of the colored image without damaging the color information, the control unit performs the process of making the image invisible while retaining the information of the original image, and redisplays the original image of the colored image that has been removed from the processing target by moving or removing the sheet. It shall be 。

[0017] and, When the colored image includes colored characters, the control unit makes the colored characters invisible by extracting the lines constituting the characters, replacing the lines with thicker lines, or arranging opaque and thicker lines on the lines. Characterized by 。

[0018] Also, When the colored image is attached on characters with low brightness handwritten and includes a colored marker teeth , the control unit makes the characters and the colored marker invisible by arranging a figure with an opaque color and a size larger than the marker on the colored marker. Following the shape of the marker line, 。<​​​​​​​​​​ It is desirable to provide the above image processing apparatus in the form of a computer-readable program.

[0022] The program is preferably installed and used on an information terminal such as a smartphone or a tablet.

Advantages of the Invention

[0025] Since the present invention has the configuration described above, while maintaining the superiority of the virtual sheet with respect to the real red sheet, even if the range of colors in the colorized image that is desired to be invisible is widened, the loss of color information in the image is eliminated, and it is difficult to leave residues, achieving both accuracy and image quality, and providing a more user-friendly image processing apparatus, program, and information terminal.

Brief Description of the Drawings

[0026] [Figure 1] A diagram showing the hardware resources of an image processing apparatus according to an embodiment of the present invention. [Figure 2] A functional block diagram of the same image processing apparatus. [Figure 3] A diagram showing the screen of the same image processing. [Figure 4] A diagram showing the position of the hue specified in the same embodiment on the HSV space. [Figure 5] A flowchart showing the outline of the processing performed by the control means in the same embodiment. [Figure 6] A diagram showing the processing method of making characters and markers invisible in the same embodiment. [Figure 7] A diagram showing an example of the processing of making characters and markers invisible in the same embodiment. [Figure 8] A diagram showing an example of the processing of making characters and markers invisible in the same embodiment. [Figure 9] A diagram showing an example of the processing of making characters and markers invisible in the same embodiment. [Figure 10] A diagram showing an example of the processing of making characters and markers invisible with conventional functions. [Figure 11]This diagram shows examples of how to make text or markers invisible using other conventional functions. [Modes for carrying out the invention]

[0027] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

[0028] The image processing apparatus of this embodiment provides a virtual learning environment for memorization using a so-called red sheet, and as shown in Figure 1, it is configured using an information terminal S such as a smartphone or tablet equipped with a microcomputer unit 1 consisting of a CPU 11, memory 12, and interface 13. By installing a program (app) P containing the functions of the image processing apparatus according to the present invention on the information terminal S, the CPU 11 sequentially reads and executes the program P, and works in cooperation with peripheral hardware resources to make the information terminal S function as the image processing apparatus X of the present invention.

[0029] As shown in the functional block of Figure 2(a), this image processing device X is configured to include a storage unit 2, an operation unit 3, a display unit 4, a processing target designation unit 5, a hue designation unit 6, and control means 7 for controlling these.

[0030] The memory unit 2 stores the note image N, which is a document image. The note image N is, for example, an image created by the user and captured by the camera 14 in Figure 1, and the control means 7 stores the captured note image N in the memory unit 2 so that it can be read. Of course, the note image N may also be one that was uploaded to the server SV from another person's information terminal PC as shown in Figure 1 and downloaded via the Web.

[0031] Notebook image N contains various types of information, including text, diagrams, illustrations, charts, maps, and photographs. In particular, notes created for memorization, like real memorization sheets, have the text to be memorized written in different colors such as red, green, and blue, or text written in relatively low-luminosity pens such as black with yellow, pink, and blue markers applied over it.

[0032] The display unit 4 is a screen that displays note image N, as shown in Figure 3(a). This screen is a touch screen of a smartphone or the like, and also functions as the operation unit 3 shown in Figure 2. When the control means 7 receives an operation from the user, for example through a button B1 displayed on the touch screen as an operation unit, it switches the screen to another note image N stored in the storage unit 2.

[0033] As shown in Figure 3(b), the processing target designation unit 5 displays a semi-transparent sheet 8 (hereinafter referred to as the "designated color sheet" in the sense of a sheet that makes the designated color invisible) corresponding to a real red sheet, overlaid on the note image N at a desired position, and accepts the designation of the range of the processing target to be made invisible. When the button B2 displayed on the operation unit of the display unit 4 is operated, the control means 7 switches the designated color sheet 8 on the screen between a displayed state (Figure 3(b)) and a hidden state (Figure 3(a)).

[0034] In this embodiment, the color of the designated color sheet 8 does not change visibility through a physical color combination with the note image N, like a real red sheet. Therefore, the combination of the color of the designated color sheet 8 and the color of the note image N that you want to make invisible can be arbitrarily defined in program P.

[0035] Here, the designated color sheet 8 is a light, semi-transparent reddish color, and the colors to be invisible are warm colors. By default, the designated color sheet 8 is rectangular in shape, fitting within the top, bottom, left, and right frames of the screen. When a movement operation is performed on the designated color sheet 8 from its default position in a two-dimensional direction via the touch screen, which is the operation unit, the control means 7 moves the display position of the designated color sheet 8 in the corresponding direction, as shown in Figure 3(c). The control means 7 may also accept and respond to operations to change the size of the designated color sheet 8.

[0036] The hue specification section 6 shown in Figure 2 is where the user specifies a range of colors (specified colors) that they want to be invisible using hue. This hue range is specified using, for example, the Hue value in the HVS space shown in Figure 4. In this embodiment, the default value is set to a continuous range H1 to H2 (H1 and H2 are numerical values ​​or codes) from pink to orange, which belongs to the warm color family. Of course, this default value may also be a cool color family, or it may be possible to select between warm and cool colors, or it may be a range that spans from warm to cool colors. Furthermore, the user may request a change in the specified color (hue) according to their purpose and application, and the control unit 7 may accept this and rewrite the specified color in the hue specification section 6.

[0037] As shown in Figure 2(b), the control means 7 includes a colored image recognition unit 71 that recognizes the position and hue of a colored image in the note image N, a hue determination unit 72 that determines whether the hue of the colored image belongs to the hue range of the color specified by the hue specification unit 6, and an image processing unit 73 that performs a process to make the colored image invisible if it is determined to belong to the hue range.

[0038] Figure 5 illustrates an overview of the image processing procedure of the control means 7. When processing starts, the processing target range is specified by the specified color sheet 8 of the processing target designation unit 5 (step S1), and the colored image recognition unit 71 automatically recognizes the shape, color pattern, and position of colored images in the note image N within the target range (step S2: image recognition step). For colored images in the note image N that are not within the target range, no image processing is performed (step S3), and the process ends. A colored image refers to, for example, a part that has a hue value between white and black. If it is a colored string, the shape, color pattern, and position of the string are recognized, and if a marker is attached to the string, the shape, color pattern, and position of the string and the marker are recognized. For example, if a notebook image contains handwritten characters "ABC" consisting of red character A, orange character B, and blue character C, as shown in Figure 6(a), a pink marker m1 placed over a black handwritten character "DE", and a green marker m2 placed over a black handwritten character "FG", the shape, color pattern, and position of these handwritten characters and markers are recognized and stored in memory unit 2. In addition to handwritten characters and markers, if there are underlines, illustrations, diagrams, maps, photographs, etc., these are also recognized as colored images.

[0039] This automatic recognition function for color images is installed in the information terminal S either as part of the initial environment or through program P.

[0040] While handwritten characters can be recognized through pattern matching and other methods, in this embodiment, handwritten characters are handled as they are, and therefore no character recognition is performed.

[0041] The hue determination unit 72 retrieves the hue values ​​(H1~H2) of the specified color specified in the hue specification unit 6, while simultaneously searching for any hue values ​​H in the colored image recognized by the colored image recognition unit 71 that belong to the specified color, i.e., the hue range (H1~H2) (Step S4: Hue determination step). Then, it extracts the colored image having the hues that it determined belong to the hue range. For example, in Figure 6(a), the warm colors are red, orange, and pink, so it extracts the colored strings AB and the marker m1 drawn in pink above the strings DE.

[0042] The image processing unit 73 performs image processing on the colored image extracted by the hue determination unit 72 to make the colored image invisible (Step S5: Image processing step).

[0043] For example, for the specified colored characters A and B, as shown in Figure 6(b), the characters A and B are made invisible by placing an opaque, thicker line on top of the lines that make up the characters A and B. Here, a mask M1 is formed by mapping an opaque line (white) consisting of a character pattern of thicker lines, widened by +α mm, onto the lines that make up the characters A and B. This process can be achieved, for example, by automatically tracing the contour of a colored image of characters with a reasonably wide line width, and then placing an opaque color inside the traced contour on top of the characters. An appropriate hue value (Hα) is assigned to the white of the line in advance. Of course, this hue value (Hα) may not be white, and may be selectable by the user.

[0044] In this embodiment, the background color of the notebook image displayed is white. The reason for using white in the above mapping is to make it blend in with the background color. However, if the hue value Hα of the specified white is different from that of the background color, the white W1 will stand out from the background color. However, since the lines that make up the characters are formed with a thicker line to create the mask M1, the characters "A" and "B" become distorted as shown in Figures 6(b) and (c), and in the mask MK1 where the characters "A" and "B" are connected, the spaces between "A" and "B" become connected, making it impossible to decipher. In this sense, simply by replacing the lines that make up the characters with a thicker line, it is possible to make the characters invisible by distorting them, even if the color of the lines is different from the background color.

[0045] The control means 7 cancels the image processing when the designated color sheet 8 is removed and redisplays the original colored image "AB" as shown in Figure 6(a).

[0046] Furthermore, for the section "DE" marked with the specified color marker m1 in Figure 6(a), the text and marker are made invisible by placing an opaque colored shape of the same or larger size as marker m1 in a position that hides marker m1 and the text DE below it. Here, as shown in Figure 6(b), a mask MK2 is formed by mapping an opaque marker (white) consisting of a shape slightly larger than the marker in the same position as the marker. This process can also be achieved, for example, by tracing the outline of the colored image marker with a reasonably wide line width, and then placing an opaque color inside the traced outline on top of the marker. An appropriate hue value (Hβ) is assigned to white. Of course, this hue value may be something other than white, and may be selectable by the user.

[0047] Here too, if the designated color sheet 8 is removed, the control means 7 cancels the image processing described above and redisplays the original colored image "DE" as shown in Figure 6(a).

[0048] In the above, no processing is performed on colored images whose hue is outside the specified range. Therefore, as shown in Figure 6(c), the green marker portion m2 drawn on the cool-toned letter "C" and the black-toned letter "FG" retains its color information even when the specified color sheet 8 is overlaid.

[0049] In Figure 6(a), the leader lines attached to symbols m1 and m2 point to solid outlines surrounding the hatched areas. These are added for explanatory purposes only; in reality, only the color of the markers shown by the hatching exists at these locations. Similarly, in Figures 6(b) and (c), the leader lines attached to symbols MK1, MK2, and M1 point to dashed outlines. These are also added for explanatory purposes only; in reality, only the white of the mapped mask shown by the hatching exists at these lines (the same applies hereafter).

[0050] In a real-world scenario, placing a red sheet on top of an image affects the colors of the underlying colored image. However, in a virtual environment, there are no constraints on the relationship between the colors of the image and the sheet. Therefore, it is optional whether or not each colored image is affected by the color 8 of the specified color sheet when the specified color sheet 8 is overlaid.

[0051] Figure 7 shows other examples of use. In the upper section of the handwritten notebook image N, "Circled number 1" is written in black, "Winter Campaign" in red, "1614", "⇒", "Reconciliation" ⇒ "The moat is filled in" are written in black, and the word "Reconciliation" is highlighted with a green marker. Next to it, there is an illustration of a castle drawn in three or more colors. In the middle section of the notebook image N, "Circled number 2" is written in black, "Summer Campaign" in red, "1615", "⇒", "The downfall of the Toyotomi family" are written in black, and the word "The downfall of the Toyotomi family" is highlighted with an orange marker.

[0052] When the specified color sheet 8 is placed over the lower half of this notebook image N, a white bold mask MK1 is formed over the red text of "Summer Campaign" as shown in Figure 8, making it invisible, and a white mask MK2 corresponding to the shape of the marker is formed over the orange marker portion of "Fall of the Toyotomi Family," making it invisible, thus creating a state of memorization. By moving or removing the specified color sheet 8 from this position, these can be displayed again in the original image state as shown in Figure 7.

[0053] If we move the designated color sheet 8 further upwards as shown in Figure 9, the "Winter Campaign" corresponds to the designated color, so a white bold mask MK1 is placed over the red text, making it invisible. "1614," "⇒," and "⇒ The moat is filled in" are written in black, so the display remains unchanged. The part of the word "Reconciliation" that has a marker is green, which is not the designated color, so the display remains unchanged. In the castle illustration, the difference from Figure 7 corresponds to the designated color and is invisible, but colors other than the designated color remain and do not disappear.

[0054] Figure 10 shows an example of applying the brightness-based monochrome function to the note image N in Figure 7 as a comparative example. When the sheets are overlaid, the red text "Winter Campaign" corresponds to the specified color and is therefore invisible. In addition to the black text (1614) and ⇒, "The moat is filled in," the green marker drawn on "Reconciliation" and the castle illustration are also monochrome-processed, making the whole image dark and difficult to see. In contrast, in Figure 9, the hue remains in the "Reconciliation" marker and the castle illustration, and color loss is suppressed, so visibility can be maintained as little as possible, especially when maps or photographs are displayed.

[0055] Figure 11 also shows another comparative example, where a function is applied to note image N in Figure 7, extracting text of a specific color (e.g., red), and marking it with a green marker to make it invisible. When the sheets are overlaid, the red text of "Summer Campaign" is converted to a marker and becomes invisible, the parts of the word "Reconciliation" that are marked with a green marker, and the non-red colored parts of the castle illustration remain unchanged, but "Winter Campaign," despite being red text, remains in an erased state. This is thought to be because the range of colors is limited, and the change in hue is judged as a mismatch. Also, if there is color unevenness, it is possible that part of "Winter Campaign" will be judged as matching and part as mismatched, resulting in partial erasure. In contrast, in Figure 9, a wide range of hue is specified, so even if the hue is slightly different, no erasure remains.

[0056] As described above, the image processing apparatus X of this embodiment comprises a storage unit 2 for storing a note image N which is a document image, a display unit 4 for displaying the note image N stored in the storage unit 2, a processing target designation unit 5 for specifying a processing target by overlaying a designated color sheet 8 on the range of the note image N on the display unit 4 that is to be made invisible, a hue designation unit 6 for specifying a range of target colors (designated colors) to be made invisible by hue, and a control means 7 for controlling these storage unit 2, display unit 4, processing target designation unit 5, and hue designation unit 6. The control means 7 includes a colored image recognition unit 71 for recognizing colored images in the note image N within the processing target, a hue determination unit 72 for determining whether the hue of the colored image belongs to the hue range specified in the hue designation unit 6, and an image processing unit 73 for performing processing to make the colored image invisible if it is determined that it belongs to the hue range.

[0057] In this way, image processing is performed on colored images that belong to the specified hue range, while image processing is not performed on colored images that do not belong to the specified hue range. As a result, the original colors are not lost, and information about the surrounding images is preserved. Moreover, by pre-specifying a range of certain hues, such as warm colors or cool colors, problems such as incomplete erasure due to slight color differences can be eliminated. Therefore, according to this embodiment, it is possible to effectively achieve both accuracy and image quality.

[0058] Of course, virtual sheets have advantages over real red sheets. That is, there is no need to link the color of colored images that you want to make invisible with the color of the sheet, and there is no need to make the marker color or the color of the sheet on the screen a dark color, so there is an advantage in terms of color selection and visibility.

[0059] Furthermore, since this embodiment primarily targets colored text and colored markers that are present in the handwritten notebook image as the target of the designated color sheet, areas marked with red pen or red marker can be used in the same way as a real red sheet, and it can be used in conjunction with a real red sheet.

[0060] Furthermore, the control unit 7 performs the process of making the image invisible while retaining the information of the original image, and redisplays the original image of the colored image that has been excluded from processing by moving or removing the specified color sheet 8. This allows for repeated display / hide without losing color information.

[0061] Specifically, if a colored image contains colored characters, the control unit 7 extracts the lines that make up the characters and places thicker lines on top of them to make the colored characters invisible. Therefore, even if the opaque, thicker lines stand out from the background color, the characters and the spaces between them become blurred, creating a state similar to drawing with an opaque marker, thus ensuring the effectiveness of the invisible state. In particular, in this embodiment, since the system only extracts the lines that make up the characters and does not recognize the characters themselves, it is not affected by the character recognition rate, and even if the characters are handwritten or tilted, it does not directly lead to any remaining traces of the characters.

[0062] Furthermore, if the colored image includes a colored marker placed on top of low-brightness text, the control unit 7 performs a process to make both the text and the colored marker invisible by placing an opaque color on top of the colored marker. This allows for a wider range of specified colors for the colored marker, and prevents partial erasure even if the colored marker itself has color inconsistencies.

[0063] Since the color used for placement is the same as or similar to the background color of note image N, it is possible to erase the area of ​​the specified color and create a state that blends more closely with the background.

[0064] Furthermore, since the sheet is rectangular and can be moved in two dimensions through user interaction, it provides a similar user experience to a real red sheet, making it extremely user-friendly.

[0065] Although one embodiment of the present invention has been described above, any method for making something invisible without impairing its visibility may be used.

[0066] For example, in addition to masking, the process of making colored text or colored markers in the above embodiment invisible can also be achieved by replacing the lines that make up the colored text with thicker lines, or by replacing the colored markers with opaque colors. Such processing can be achieved by applying a color replacement function over a wide range of hues.

[0067] If the background color can be recognized and a color of the same hue as the background color can be used, the lines and markers of the colored text can be replaced with that color. In this case, it is possible to reliably create a state where the text is invisible without replacing it with a line thicker than the lines that make up the colored text.

[0068] Furthermore, if the above device is considered methodologically, a method is used in which a note image is displayed on the screen, and a sheet is superimposed on the area of ​​the note image that is to be made invisible. In this method, colored images belonging to a predetermined hue range are made invisible within that area, and no processing is performed on colored images of other hues. This method achieves the same effects as the image processing device X of the above embodiment.

[0069] Furthermore, although the specified color sheet was rectangular in the above embodiment, other shapes such as polygons, circles, or ellipses can be used as long as they can be moved in a two-dimensional direction through user operation.

[0070] Furthermore, although a reddish, semi-transparent sheet was used for the specified color sheet in the above embodiment, other colors may be used, and a transparent sheet with a frame may also be used.

[0071] Furthermore, while the above embodiment made specified color text and specified color markers in the note image invisible, if there is an environment in which text and markers can be added to the loaded image, this does not preclude making the text and markers added in accordance with the above process invisible as well.

[0072] Furthermore, the document image may be an image of a reference book or other document in addition to a notebook, and other configurations can also be modified in various ways without departing from the spirit of the present invention. [Explanation of Symbols]

[0073] 2...Storage section 4...Display section 5... Processing target designation section 6...Hue specification section 7…Control means 8…Specified color sheet 71…Image Recognition Unit 72...Hue determination section 73…Image Processing Unit N...Document image (notebook image) S... Information terminal X...Image processing device

Claims

1. The system comprises a storage unit for storing document images, a display unit for displaying document images stored in the storage unit, a processing target designation unit for specifying the processing target by overlaying a sheet over the range of the document image on the display unit that will be made invisible, a hue designation unit for specifying the range of target colors to be made invisible by hue, and control means for controlling the storage unit, display unit, range designation unit, and hue designation unit. The control means is an image processing apparatus comprising: a colored image recognition unit that recognizes a colored image in the document image within the processing target; a hue determination unit that determines whether the hue of the colored image belongs to the hue range specified in the hue specification unit; and an image processing unit that performs processing to make the colored image invisible if it is determined that it belongs to the hue range. The control unit performs a process to make the image invisible while retaining the information of the original image, and then redisplays the original image of the colored image that was removed from the processing target due to the movement or removal of the sheet. Image processing apparatus characterized in that, when the colored image includes colored characters, the control unit extracts the lines constituting the characters and replaces those lines with thicker lines, or places opaque, thicker lines on top of those lines, thereby making the colored characters invisible.

2. The system comprises a storage unit for storing document images, a display unit for displaying document images stored in the storage unit, a processing target designation unit for specifying the processing target by overlaying a sheet over the range of the document image on the display unit that will be made invisible, a hue designation unit for specifying the range of target colors to be made invisible by hue, and control means for controlling the storage unit, display unit, range designation unit, and hue designation unit. The control means is an image processing apparatus comprising: a colored image recognition unit that recognizes a colored image in the document image within the processing target; a hue determination unit that determines whether the hue of the colored image belongs to the hue range specified in the hue specification unit; and an image processing unit that performs processing to make the colored image invisible if it is determined that it belongs to the hue range. The control unit performs a process to make the image invisible while retaining the information of the original image, and then redisplays the original image of the colored image that was removed from the processing target due to the movement or removal of the sheet. Image processing apparatus characterized in that, when the colored image includes a handwritten colored marker placed on top of low-luminance characters, the control unit makes the characters and the colored marker invisible by placing an opaque colored figure larger than the marker along the shape of the marker's line on top of the colored marker.

3. The image processing apparatus according to claim 1 or 2, wherein the color used for substitution or placement is the same as or similar to the background color of the document image.

4. The image processing apparatus according to claim 1 or 2, wherein the sheet is rectangular, polygonal, circular, or elliptical in shape and can be moved in a two-dimensional direction through user operation.

5. A program that is loaded into a computer and causes the computer to function as an image processing device according to claim 1 or 2.

6. An information terminal characterized by having the program described in Claim 5 installed.

Images