A laser printer image density correction method, device, equipment and medium

Abstract

The application is suitable for the technical field of image processing, and provides a laser printer image density correction method, device, equipment and medium. The laser printer image density correction method comprises the following steps: dividing a printing image corresponding to to-be-printed data into a plurality of standard unit blocks; placing each standard aliquot in a plane coordinate system, and obtaining vertex coordinates of the standard aliquot in the plane coordinate system; determining a reference coordinate point of the standard aliquot in the plane coordinate system by using the vertex coordinates; scanning the divided printing image to obtain a mapping image; comparing the printing image and the mapping image to determine a distorted unit block in the mapping image that is distorted; and correcting the distorted unit block in the mapping image by using the reference coordinate point of the standard aliquot in the plane coordinate system to obtain a density-corrected mapping image. The laser printer image density correction method can improve the effect of image density correction.

Description

Technical Field

[0001] This application relates to the field of image processing technology, and in particular to a method, apparatus, device and medium for image density correction of a laser printer. Background Technology

[0002] An image forming apparatus is a device that forms an image on a recording medium using imaging principles. Examples include printers, copiers, fax machines, multifunction image processing and copying devices, electrostatic printing devices, and any other similar devices. To perform image forming operations using an image forming apparatus, control equipment typically converts print data into printer language and sends this printer language to the image forming apparatus. Image density reflects the depth of the image. Many factors influence image density during image forming. For example, changes in environmental conditions such as temperature or humidity, large gaps between the print source and the scanning device, and voltage variations can all affect the image density. Therefore, image density correction is necessary during image forming.

[0003] Existing printer image density correction methods often involve directly sampling the endpoints and coordinate points of the image, and then filling or deleting based on these parameters to correct the image density. However, this correction method is prone to omissions, resulting in poor image density correction effects that are difficult to visually identify. Summary of the Invention

[0004] This application provides a laser printer image density correction method, apparatus, device, and medium, which can solve the problem of poor image density correction effect.

[0005] In a first aspect, embodiments of this application provide a laser printer image density correction method, which includes:

[0006] The print image corresponding to the data to be printed is divided into multiple standard unit blocks; each standard unit block includes multiple standard equal parts.

[0007] For each standard segment, place the standard segment in a plane coordinate system, and obtain the vertex coordinates of the standard segment in the plane coordinate system. Use the vertex coordinates to determine the reference coordinate point of the standard segment in the plane coordinate system. The plane coordinate system is a two-dimensional rectangular coordinate system constructed with the scanning start point of the laser printer's scanning system as the origin.

[0008] The mapped image is obtained by scanning the segmented printed image;

[0009] By comparing the printed image and the mapped image, the distorted unit blocks in the mapped image are identified;

[0010] By using standard equally spaced reference coordinate points in a planar coordinate system, the distorted unit blocks in the mapped image are corrected to obtain a density-corrected mapped image.

[0011] Optionally, the vertex coordinates of the i-th standard segment of the k-th standard cell block among multiple standard cell blocks are:

[0012] {i1(x1, y1); i2(x2, y1); i3(x1, y2); i4(x2, y2)}

[0013] Where i∈E, i=1,2,...,I,E is the index matrix of the standard divisions, containing I elements, k=1,2,...,K,K represents the total number of standard unit blocks, i1(x1,y1) represents the coordinates of the first vertex of the i-th standard division of the k-th standard unit block, i2(x2,y1) represents the coordinates of the second vertex of the i-th standard division of the k-th standard unit block, i3(x1,y2) represents the coordinates of the third vertex of the i-th standard division of the k-th standard unit block, and i4(x2,y2) represents the coordinates of the fourth vertex of the i-th standard division of the k-th standard unit block. x1 and x2 both represent the x-coordinate values, and y1 and y2 both represent the y-coordinate values.

[0014] Optionally, the reference coordinate points of the standard equal parts in the planar coordinate system are determined using the vertex coordinates, including:

[0015] Through the formula:

[0016]

[0017]

[0018] Calculate the reference coordinate point p of the i-th standard segment of the k-th standard cell block. i (a i b i );

[0019] Among them, a i Represents the reference coordinate point p i The x-coordinate value, b i Indicates the location point p i The ordinate value.

[0020] Optionally, the mapped image includes mapped blocks that correspond one-to-one with multiple standard unit blocks;

[0021] By comparing the printed image and the mapped image, the warped unit blocks in the mapped image that have been distorted are identified, including:

[0022] For each mapping block, compare the shape of the mapping block with the shape of the corresponding standard unit block;

[0023] If the shape of the mapped block is different from the shape of the standard cell block corresponding to the mapped block, then the mapped block is determined to be a twisted cell block that has been twisted.

[0024] Optionally, the standard cell block corresponding to the kth twist cell block is the kth standard cell block of the printed image, and the kth twist cell block contains I twisted equal parts.

[0025] Optionally, the distorted unit blocks in the mapped image are corrected using reference coordinate points that are equally divided in a planar coordinate system, resulting in a density-corrected mapped image, including:

[0026] For the i-th twisted portion of the k-th twisted unit block, if i is not the element of the middle column of E, then the reference vertex coordinates of the i-th twisted portion of the k-th twisted unit block are obtained by using the reference coordinate point of the standard portion of the k-th standard unit block in the plane coordinate system.

[0027] If i is the element in the middle column of E, then the reference vertex coordinates of the i-th twisted segment are obtained by using the reference vertex coordinates of the twisted segment adjacent to the i-th twisted segment in the k-th twisted unit block.

[0028] The reference vertex coordinates of the i-th twisted segment of the k-th twisted unit block are corrected based on the reference vertex coordinates of the i-th twisted segment of the k-th twisted unit block.

[0029] If the total number of columns in E is even, then the middle column of E is the two middle columns; if the total number of columns in E is odd, then the middle column of E is the one middle column.

[0030] Optionally, using the reference coordinates of the standard divisions of the k-th standard unit block in the planar coordinate system, the reference vertex coordinates of the i-th twisted division of the k-th twisted unit block are obtained, including:

[0031] Through the formula:

[0032] Δa i，j =|a j -a i |

[0033] Calculate the correction spacing Δa on the horizontal axis between the i-th twisted segment and the j-th twisted segment. i，j ;

[0034] Among them, a i The reference coordinate point p represents the i-th equal part of the k-th standard unit block of the printed image. i The x-coordinate value, a j The reference coordinate point p represents the j-th equal part of the k-th standard unit block of the printed image. jThe x-coordinate value, the j-th part is the part adjacent to the i-th part, k = 1, 2, ..., K, K represents the total number of standard unit blocks, j ≠ i, i, j ∈ E, E is the index matrix of the standard parts, containing I elements;

[0035] Through the formula:

[0036] Δb i，j =|b j -b i |

[0037] Calculate the correction spacing Δb between the i-th twisted segment and the j-th twisted segment on the ordinate. i，j ;

[0038] Among them, b i The reference coordinate point p represents the k-th standard cell block of the printed image. i The ordinate value, b j The reference coordinate point p represents the j-th equal part of the k-th standard unit block of the printed image. j The ordinate value;

[0039] Based on the correction interval Δa of the horizontal axis i，j Correction spacing Δb between the vertical and horizontal axes i，j Correct the spacing between the vertices of the i-th twisted segment to obtain the reference vertex coordinates of the i-th twisted segment of the k-th twisted unit block.

[0040] Secondly, embodiments of this application provide a laser printer image density correction device, comprising:

[0041] The partitioning module is used to divide the print image corresponding to the data to be printed into multiple standard unit blocks; each standard unit block includes multiple standard equal parts.

[0042] The calculation module is used to place each standard segment in a planar coordinate system, obtain the vertex coordinates of the standard segment in the planar coordinate system, and use the vertex coordinates to determine the reference coordinate point of the standard segment in the planar coordinate system; the planar coordinate system is a two-dimensional rectangular coordinate system constructed with the scanning start point of the laser printer's scanning system as the origin;

[0043] The scanning module is used to scan the divided printed image to obtain the mapped image;

[0044] The comparison module is used to compare the printed image and the mapped image to identify the distorted unit blocks in the mapped image.

[0045] The correction module uses standard equally spaced reference coordinate points in a planar coordinate system to correct the distorted unit blocks in the mapped image, resulting in a density-corrected mapped image.

[0046] Thirdly, embodiments of this application provide a laser printer, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the aforementioned laser printer image density correction method.

[0047] Fourthly, embodiments of this application provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the aforementioned laser printer image density correction method.

[0048] The above-mentioned solution in this application has the following beneficial effects:

[0049] In the embodiments of this application, the printed image corresponding to the data to be printed is divided into multiple standard unit blocks. For each standard unit block, it is placed in a planar coordinate system, and the vertex coordinates of the standard unit block are obtained within this system. The vertex coordinates are used to determine the reference coordinate points of the standard unit block within the planar coordinate system. The divided printed image is then scanned to obtain a mapped image. The printed image and the mapped image are then compared to identify the distorted unit blocks in the mapped image. Finally, the reference coordinate points of the standard unit blocks within the planar coordinate system are used to correct the distorted unit blocks in the mapped image, resulting in a density-corrected mapped image. Dividing the printed image corresponding to the data to be printed into multiple standard unit blocks, and further dividing each standard unit block into multiple standard parts, allows for detailed division of the printed image. Scanning the divided printed image to obtain the mapped image makes the shape changes of the distorted unit blocks before and after correction easy to observe, and the effect of image density correction is easily identifiable. Using the reference coordinate points of the standard unit blocks within the planar coordinate system to correct the distorted unit blocks in the mapped image improves the accuracy of the correction, thus enhancing the image density correction effect.

[0050] Other beneficial effects of this application will be described in detail in the following detailed description section. Attached Figure Description

[0051] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0052] Figure 1 A flowchart illustrating a laser printer image density correction method provided in an embodiment of this application;

[0053] Figure 2A schematic diagram of a printed image provided in an embodiment of this application;

[0054] Figure 3 A schematic diagram of a standard unit block provided in an embodiment of this application;

[0055] Figure 4 A schematic diagram illustrating the correction of a twisted unit block provided in an embodiment of this application;

[0056] Figure 5 A flowchart illustrating a laser printer image density correction method according to an embodiment of this application;

[0057] Figure 6 This is a structural diagram of a laser printer image density correction device provided in an embodiment of this application;

[0058] Figure 7 This is a structural diagram of a laser printer provided in one embodiment of this application. Detailed Implementation

[0059] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0060] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0061] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0062] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if detected [the described condition or event]" may be interpreted, depending on the context, as meaning "once determined," "in response to determination," "once detected [the described condition or event]," or "in response to detection [the described condition or event]."

[0063] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0064] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0065] To address the issue of poor image density correction performance, this application provides a laser printer image density correction method. This method involves dividing the print image corresponding to the data to be printed into multiple standard unit blocks. For each standard unit block, a planar coordinate system is established, and the vertex coordinates of the standard unit block are obtained within this system. The vertex coordinates are used to determine the reference coordinate points of the standard unit block within the planar coordinate system. The divided print image is then scanned to obtain a mapped image. The print image and the mapped image are compared to identify the distorted unit blocks in the mapped image. Finally, the reference coordinate points of the standard unit blocks within the planar coordinate system are used to correct the distorted unit blocks in the mapped image, resulting in a density-corrected mapped image. The process involves dividing the printed image corresponding to the data to be printed into multiple standard unit blocks, and then further dividing each standard unit block into multiple standard equal parts. This allows for detailed division of the printed image. The divided printed image is then scanned to obtain a mapped image. The shape changes of the distorted unit blocks in the mapped image before and after correction are easily observed, and the effect of image density correction is easily identifiable. By using the reference coordinate points of the standard equal parts in the plane coordinate system to correct the distorted unit blocks in the mapped image, the accuracy of correction can be improved, thereby enhancing the image density correction effect.

[0066] The laser printer image density correction method provided in this application will be described exemplarily below.

[0067] like Figure 1 As shown, the laser printer image density correction method provided in this application includes the following steps:

[0068] Step 11: Divide the print image corresponding to the data to be printed into multiple standard unit blocks.

[0069] Each of the above standard unit blocks comprises multiple standard equal parts.

[0070] It should be noted that multiple standard unit blocks can be of equal size; the size of a standard unit block can be the smallest pixel that the laser printer's scanning system can scan.

[0071] For example, the printed image is divided into K standard unit blocks, each of which is rectangular and of equal size. Each standard unit block includes I standard parts, and the size of each standard part is the smallest pixel point scanned by the scanning system of the laser printer. Thus, the size of the standard unit block is the size of I smallest pixels.

[0072] For example, a printed image can be like this Figure 2 As shown, the printed image is a 9×8 pixel image, divided into 12 standard unit blocks, each of which comprises 6 standard parts, for a total of 72 standard parts. Each grid in the image represents a standard part, and each standard part is one pixel in size. Black grids represent black pixels, and white grids represent white pixels.

[0073] It is worth mentioning that dividing the printed image into multiple standard unit blocks, and further dividing each standard unit block into multiple standard equal parts, allows for detailed division of the printed image. This enables the use of the smallest pixel scanned by the laser printer's scanning system as the processing object for image density correction, allowing for precise correction of image density.

[0074] Step 12: For each standard segment, place the standard segment in a plane coordinate system, obtain the vertex coordinates of the standard segment in the plane coordinate system, and use the vertex coordinates to determine the reference coordinate point of the standard segment in the plane coordinate system.

[0075] The aforementioned planar coordinate system is a two-dimensional rectangular coordinate system constructed with the scanning start point of the laser printer's scanning system as the origin.

[0076] In some embodiments of this application, the standard equal parts are placed in a planar coordinate system, and the vertex coordinates of the standard equal parts are obtained in the planar coordinate system. The reference coordinate points of the standard equal parts in the planar coordinate system are determined using the vertex coordinates. Specifically, the steps include the following:

[0077] The first step is to place the standard equal parts in a planar coordinate system, and obtain the vertex coordinates of the i-th standard equal part of the k-th standard unit block among multiple standard unit blocks:

[0078] {i1(x1, y1); i2(x2, y1); i3(x1, y2); i4(x2, y2)}

[0079] Where i∈E, i=1,2,...,I, E is the index matrix of the standard segments, containing I elements, k=1,2,...,K, K represents the total number of standard unit blocks, i1(x1,y1) represents the coordinates of the first vertex of the i-th standard segment of the k-th standard unit block, i2(x2,y1) represents the coordinates of the second vertex of the i-th standard segment of the k-th standard unit block, i3(x1,y2) represents the coordinates of the third vertex of the i-th standard segment of the k-th standard unit block, and i4(x2,y2) represents the coordinates of the first vertex of the i-th standard segment of the k-th standard unit block. The coordinates of the fourth vertex of the i-th standard segment of the element block are given. x1 represents the x-coordinates of the first and third vertices of the i-th standard segment of the k-th standard element block. x2 represents the x-coordinates of the second and fourth vertices of the i-th standard segment of the k-th standard element block. y1 represents the y-coordinates of the first and second vertices of the i-th standard segment of the k-th standard element block. y2 represents the y-coordinates of the third and fourth vertices of the i-th standard segment of the k-th standard element block.

[0080] It should be noted that the elements in the above-mentioned standard equal-part number matrix are the sequentially ordered numbers of the standard equal parts, and the dimension of the number matrix varies depending on the different division methods of the standard cell block. For example, if the standard cell block is divided into 9 standard equal parts in a 3×3 manner, and the numbers of the standard equal parts are ordered sequentially starting from the first column of the first row, then the standard equal-part number matrix is ​​a 3×3 matrix with 9 elements, and the element order is the same as that of the standard equal parts mentioned above.

[0081] The second step is to determine the reference coordinate points of the standard equal parts in the planar coordinate system using the vertex coordinates. Specifically, this is done using the formula:

[0082]

[0083]

[0084] Calculate the reference coordinate point p of the i-th standard segment of the k-th standard cell block. i (a i b i );

[0085] Among them, a i Represents the reference coordinate point p i The x-coordinate value, b i Indicates the location point p i The ordinate value.

[0086] The above standard unit block will be illustrated below with a specific example.

[0087] like Figure 3As shown, the standard unit block is divided into 3×2 sections, resulting in six standard equal parts. Both the standard unit block and the standard equal parts are rectangles. For the first standard equal part, by reading the coordinates of its vertices on the x-axis (horizontal axis) and y-axis (vertical axis), we obtain the coordinates of its first vertex as 11(0,2), the second vertex as 12(1,2), the third vertex as 13(0,1), and the fourth vertex as 14(1,1). Similarly, the vertex coordinates of the second standard division are 21(1,2), 22(2,2), 33(1,1), and 34(2,1); the vertex coordinates of the third standard division are 31(2,2), 32(3,2), 33(2,1), and 34(3,1); the vertex coordinates of the fourth standard division are 41(0,1), 42(1,1), 43(0,0), and 44(1,0); the vertex coordinates of the fifth standard division are 51(1,1), 52(2,1), 53(1,0), and 54(2,0); and the vertex coordinates of the sixth standard division are 61(2,1), 62(3,1), 63(2,0), and 64(3,0).

[0088] It is worth mentioning that the reference coordinate points are used to reference the spacing between standard equal parts.

[0089] Step 13: Scan the divided printed image to obtain the mapped image.

[0090] In some embodiments of this application, the divided printed image can be scanned by the scanning system of a laser printer to obtain a mapped image.

[0091] It should be noted that mapped images can be obtained using common scanning techniques, such as laser spot scanning, line scanning, and general scanning. During the process of obtaining a mapped image, factors such as voltage, static electricity, and scanning system instability may cause distortion in the mapped image.

[0092] Step 14: Compare the printed image and the mapped image to identify the distorted unit blocks in the mapped image.

[0093] The above-mentioned mapped image includes mapped blocks that correspond one-to-one with multiple standard unit blocks.

[0094] Specifically, for each mapping block, the shape of the mapping block is compared with the shape of the standard unit block corresponding to the mapping block; if the shape of the mapping block is different from the shape of the standard unit block corresponding to the mapping block, the mapping block is determined to be a distorted unit block that has been distorted; if the shape of the mapping block is the same as the shape of the unit block corresponding to the standard mapping block, the mapping block is determined to be not distorted.

[0095] It should be noted that the standard cell block corresponding to the kth twisted cell block is the kth standard cell block of the printed image, and the kth twisted cell block contains I twisted equal parts.

[0096] For example, for the kth mapping block, its corresponding standard unit block is the kth standard unit block of the printed image. The kth standard unit block is a rectangle. The shape of the kth mapping block is compared with the shape of the kth standard unit block. If the shape of the kth mapping block is not a rectangle, or is different in shape and size from the kth standard unit block, then the kth mapping block is determined to be distorted and is a distorted unit block. If the shape of the kth mapping block is a rectangle and is the same in shape and size as the kth standard unit block, then the kth mapping block is determined not to be distorted and does not need to be corrected.

[0097] It is worth mentioning that by comparing the printed image and the mapped image, the distorted cell blocks that are distorted in the mapped image can be identified, and the object to be corrected can be determined.

[0098] Step 15: Correct the distorted unit blocks in the mapped image using standard equally divided reference coordinate points in the planar coordinate system to obtain the density-corrected mapped image.

[0099] In some embodiments of this application, the above steps include:

[0100] The first step is to obtain the reference vertex coordinates of the i-th twisted part of the k-th twisted unit block if i is not the element of the middle column of E, using the reference coordinate point of the standard part of the k-th standard unit block in the plane coordinate system.

[0101] Specifically, through the formula:

[0102] Δa i，j =|a j -a i |

[0103] Calculate the correction spacing Δa on the horizontal axis between the i-th twisted segment and the j-th twisted segment. i，j ;

[0104] Among them, a i The reference coordinate point p represents the i-th equal part of the k-th standard unit block of the printed image. i The x-coordinate value, a j The reference coordinate point p represents the j-th equal part of the k-th standard unit block of the printed image. j The x-coordinate value, the j-th part is the part adjacent to the i-th part, k = 1, 2, ..., K, K represents the total number of standard unit blocks, j ≠ i, i, j ∈ E, E is the index matrix of the standard parts, containing I elements;

[0105] Through the formula:

[0106] Δb i，j =|b j -b i |

[0107] Calculate the correction spacing Δb between the i-th twisted segment and the j-th twisted segment on the ordinate. i，j ;

[0108] Among them, b i The reference coordinate point p represents the k-th standard cell block of the printed image. i The ordinate value, b j The reference coordinate point p represents the j-th equal part of the k-th standard unit block of the printed image. j The ordinate value;

[0109] Based on the correction interval Δa of the horizontal axis i，j Correction spacing Δb between the vertical and horizontal axes i，j Correct the spacing between the vertices of the i-th twisted segment to obtain the reference vertex coordinates of the twisted segment;

[0110] The second step is to obtain the reference vertex coordinates of the i-th twisted segment by using the reference vertex coordinates of the twisted segment adjacent to the i-th twisted segment in the k-th twisted unit block.

[0111] The third step is to correct the reference vertex coordinates of the i-th twisted segment of the k-th twisted unit block based on the reference vertex coordinates of the i-th twisted segment of the k-th twisted unit block.

[0112] If the total number of columns in E is even, then the middle column of E is the two middle columns; if the total number of columns in E is odd, then the middle column of E is the one middle column.

[0113] Specifically, the vertices that are twisted into equal parts are moved to the corresponding reference vertex coordinates.

[0114] For example, if the sequence matrix has 5 columns, then the middle column of the sequence matrix is ​​the 3rd column; if the sequence matrix has 4 columns, then the middle columns of the sequence matrix are the 2nd and 3rd columns. For a twisted unit block with a 3×2 partitioning, if the coordinates of the first vertex of its first twisted segment are 1′1(x′1, y′1), the correction distance Δa between the first and second twisted segments on the horizontal coordinate can be obtained through the standard unit block corresponding to this twisted unit block. 1，2 and the correction spacing Δb on the vertical axis 1，2 The correction spacing Δa on the horizontal axis between the first and fourth twisted equal parts. 1，4 and the correction spacing Δb on the vertical axis1，4 Then the reference vertex coordinates of the second vertex of the first twisted division are 1′2(x′1+Δa). 1，2 y′1+Δb 1，2 The reference vertex coordinates of the third vertex of the first twisted division are 1′3(x′1+Δa). 1，4 y′1+Δb 1，4 The reference vertex coordinates of the fourth vertex of the first twisted division are 1′4(x′1+Δa). 1，2 +Δa 1，4 y′1+Δb 1，2 +Δb 1，4 The coordinates of the four vertices of the first twisted segment are moved to the corresponding reference vertex coordinates to complete the correction of the first twisted segment. Similarly, the third, fourth, and sixth twisted segments are corrected. Based on the corrected twisted segments, the reference vertex coordinates of the second and fifth twisted segments are determined, and the second and fifth twisted segments are corrected to complete the correction of the twisted unit block.

[0115] The coordinates of the first vertex of the aforementioned twisted segment are determined as follows: It is determined whether the twisted segments adjacent to the twisted segment have been corrected. If so, the reference vertex coordinates of the common vertex between the corrected twisted segment and the twisted segment are used as the coordinates of the first vertex of the twisted segment. For example, in the above example, when correcting the fourth twisted segment, the coordinates of the first vertex of the fourth twisted segment are determined to be 4′1(x′1+Δa). 1，4 y′1+Δb 1，4 Otherwise, the coordinates of the first vertex are taken from the four vertices of the twisted division that do not share any other twisted divisions.

[0116] It is worth mentioning that the reference vertex coordinates of the twisted equal parts in the middle column are determined by the reference vertex coordinates of the adjacent twisted equal parts, which can reduce the influence of the middle part of the twisted unit block during correction and improve the smoothness of the corrected unit block.

[0117] The above steps will be illustrated with a specific example below.

[0118] like Figure 4 As shown, a standard cell block divided into six standard parts (the first, second, third, fourth, fifth, and sixth standard parts) undergoes a change in shape in the resulting mapped image after scanning. The vertex coordinates of the six standard parts change on both the horizontal (x-axis) and vertical (y-axis) axes, resulting in a distorted cell block. After correction, the distorted cell block regains its standard shape.

[0119] It can be seen that using standard equally divided reference coordinate points in the plane coordinate system to correct the distorted unit blocks in the mapped image can improve the accuracy of the correction and improve the correction effect of the mapped image.

[0120] The laser printer image density correction method provided in this application will be illustrated below with a specific example.

[0121] like Figure 5 As shown, the original image (i.e., the print image corresponding to the above-mentioned data to be printed) is scanned by the scanning module of the laser printer to obtain a mapping image (i.e., the above-mentioned mapping image). After the mapping image is density corrected, if the preset effect is not achieved, the density of the density-corrected mapping image is re-corrected until the preset effect is achieved. The density-corrected mapping image is then used as the print image, and the laser printer prints the print image.

[0122] It is worth mentioning that dividing the printed image corresponding to the data to be printed into multiple standard unit blocks, and further dividing each standard unit block into multiple standard equal parts, allows for detailed division of the printed image. Scanning the divided printed image yields a mapping image, where the shape changes of the distorted unit blocks before and after correction are easily observed, and the effect of image density correction is easily identifiable. Using the reference coordinate points of the standard equal parts in the planar coordinate system to correct the distorted unit blocks in the mapping image can improve the accuracy of correction and enhance the correction effect of the mapping image.

[0123] The laser printer image density correction device provided in this application will be described exemplarily below.

[0124] like Figure 6 As shown, this application embodiment provides a laser printer image density correction device 600, which includes:

[0125] The partitioning module 601 is used to divide the print image corresponding to the data to be printed into multiple standard unit blocks; each standard unit block includes multiple standard equal parts.

[0126] The calculation module 602 is used to place each standard segment in a plane coordinate system, obtain the vertex coordinates of the standard segment in the plane coordinate system, and use the vertex coordinates to determine the reference coordinate point of the standard segment in the plane coordinate system; the plane coordinate system is a two-dimensional rectangular coordinate system constructed with the scanning start point of the laser printer's scanning system as the origin;

[0127] Scanning module 603 is used to scan the divided printed image to obtain a mapped image;

[0128] The comparison module 604 is used to compare the printed image and the mapped image to identify the distorted unit blocks in the mapped image.

[0129] The correction module 605 uses standard equally divided reference coordinate points in the plane coordinate system to correct the distorted unit blocks in the mapped image, thereby obtaining a density-corrected mapped image.

[0130] It should be noted that the information interaction and execution process between the above-mentioned devices / units are based on the same concept as the method embodiments of this application. For details on their specific functions and technical effects, please refer to the method embodiments section, and they will not be repeated here.

[0131] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0132] like Figure 7 As shown, an embodiment of this application provides a laser printer, wherein the laser printer D10 of this embodiment includes: at least one processor D100 ( Figure 7 The diagram shows only one processor, a memory D101, and a computer program D102 stored in the memory D101 and executable on the at least one processor D100, wherein the processor D100 executes the computer program D102 to implement the steps in any of the above method embodiments.

[0133] Specifically, when the processor D100 executes the computer program D102, it divides the print image corresponding to the data to be printed into multiple standard unit blocks. Then, for each standard unit block, it places the standard unit block in a planar coordinate system and obtains the vertex coordinates of the standard unit block in the planar coordinate system. It uses the vertex coordinates to determine the reference coordinate points of the standard unit block in the planar coordinate system. Then, it scans the divided print image to obtain a mapped image. Then, it compares the print image and the mapped image to determine the distorted unit blocks in the mapped image. Finally, it uses the reference coordinate points of the standard unit blocks in the planar coordinate system to correct the distorted unit blocks in the mapped image to obtain a density-corrected mapped image. The process involves dividing the printed image corresponding to the data to be printed into multiple standard unit blocks, and then further dividing each standard unit block into multiple standard equal parts. This allows for detailed division of the printed image. The divided printed image is then scanned to obtain a mapped image. The shape changes of the distorted unit blocks in the mapped image before and after correction are easily observed, and the effect of image density correction is easily identifiable. By using the reference coordinate points of the standard equal parts in the plane coordinate system to correct the distorted unit blocks in the mapped image, the accuracy of correction can be improved, thereby enhancing the image density correction effect.

[0134] The processor D100 can be a central processing unit (CPU), or it can be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0135] In some embodiments, the memory D101 can be an internal storage unit of the laser printer D10, such as the hard drive or memory of the laser printer D10. In other embodiments, the memory D101 can also be an external storage device of the laser printer D10, such as a plug-in hard drive, smart media card (SMC), secure digital card (SD), flash card, etc., equipped on the laser printer D10. Furthermore, the memory D101 can include both internal and external storage units of the laser printer D10. The memory D101 is used to store the operating system, applications, bootloader, data, and other programs, such as the program code of the computer program. The memory D101 can also be used to temporarily store data that has been output or will be output.

[0136] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps described in the various method embodiments above.

[0137] This application provides a computer program product that, when run on a laser printer, enables the laser printer to perform the steps described in the above-described method embodiments.

[0138] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments of this application can be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include at least: any entity or device capable of carrying the computer program code to a laser printer image density correction method device / terminal device, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium. Examples include USB flash drives, portable hard drives, magnetic disks, or optical disks. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electrical carrier signals or telecommunication signals.

[0139] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0140] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0141] The above description is the preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principles described in this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A method for image density correction in a laser printer, characterized in that, include: The print image corresponding to the data to be printed is divided into multiple standard unit blocks; each standard unit block includes multiple standard equal parts; For each standard segment, the standard segment is placed in a planar coordinate system, and the vertex coordinates of the standard segment are obtained in the planar coordinate system. The vertex coordinates are used to determine the reference coordinate point of the standard segment in the planar coordinate system. The planar coordinate system is a two-dimensional rectangular coordinate system constructed with the scanning start point of the laser printer's scanning system as the origin. The mapped image is obtained by scanning the segmented printed image; By comparing the printed image and the mapped image, the distorted unit blocks in the mapped image that have been distorted are identified; The distorted unit blocks in the mapped image are corrected using the reference coordinate points in the plane coordinate system that are equally divided according to the standard, so as to obtain a density-corrected mapped image; No. The standard unit block corresponding to the twisted unit block is the first twisted unit block of the printed image. The first standard unit block, the first Each twisted unit block contains A distorted equal part; The step of correcting the distorted unit blocks in the mapped image using the standard equally divided reference coordinate points in the planar coordinate system to obtain a density-corrected mapped image includes: Regarding the first The first twisted unit block A distorted equal part, if no The element in the middle column is then determined using the method described above. The standard divisions of each standard unit block are reference coordinate points in the planar coordinate system to obtain the first... The first twisted unit block The coordinates of a twisted, equally divided reference vertex; A standard equally divided index matrix containing One element, , ; like yes The element in the middle column is then determined using the method described above. In the twisted unit block, with the first The coordinates of the reference vertices of the adjacent twisted equal parts are obtained to obtain the first twisted equal parts. The coordinates of a twisted, equally divided reference vertex; Based on the The first twisted unit block The first distorted equal-part reference vertex coordinate correction The first twisted unit block The coordinates of the distorted, equally divided vertex; Among them, if If the total number of columns is even, then The middle column is the two middle columns, if If the total number of columns is odd, then The middle column is the very middle column.

2. The laser printer image density correction method according to claim 1, characterized in that, The first of the multiple standard unit blocks The first standard unit block The coordinates of the vertices of each standard division are: in, , , The standard equally divided index matrix contains One element, , This represents the total number of the standard unit blocks. Indicates the first The first standard unit block The coordinates of the first vertex of each standard division Indicates the first The first standard unit block The coordinates of the second vertex in each of the standard equal parts. Indicates the first The first standard unit block The coordinates of the third vertex of each of the standard equal parts. Indicates the first The first standard unit block The coordinates of the fourth vertex in each of the standard equal parts. and All represent x-axis values. and All represent the ordinate values.

3. The laser printer image density correction method according to claim 2, characterized in that, The step of determining the reference coordinate points of the standard equal parts in the planar coordinate system using the vertex coordinates includes: Through the formula: Calculate the first The first standard unit block Reference coordinate points divided into standard equal parts ; in, Indicates the reference coordinate point The x-coordinate value, Indicates location point The ordinate value.

4. The laser printer image density correction method according to claim 1, characterized in that, The mapped image includes mapping blocks that correspond one-to-one with the plurality of standard unit blocks; The step of comparing the printed image and the mapped image to determine the distorted unit blocks in the mapped image includes: For each of the mapping blocks, the shape of the mapping block is compared with the shape of the standard unit block corresponding to the mapping block; If the shape of the mapping block is different from the shape of the standard cell block corresponding to the mapping block, then the mapping block is determined to be a twisted cell block that has been twisted.

5. The laser printer image density correction method according to claim 1, characterized in that, The use of the first The standard divisions of each standard unit block are reference coordinate points in the planar coordinate system to obtain the first... The first twisted unit block The coordinates of the reference vertex, which are divided into three equally distorted parts, include: Through the formula: Calculate the first The twisted equal parts and the first The correction spacing between the twisted equal parts on the horizontal axis ; in, The first character of the printed image The first standard unit block Equal division of reference coordinate points The x-coordinate value, The first character of the printed image The first standard unit block Equal parts of reference coordinate points The x-coordinate value, the first The first equal part is the same as the first... Adjacent equal parts, , This represents the total number of the standard unit blocks. , , The standard equally divided index matrix contains One element; Through the formula: Calculate the first The twisted equal parts and the first Correction spacing between the twisted equal parts on the vertical axis ; in, The first character of the printed image Reference coordinates of a standard unit block The ordinate value, The first character of the printed image The first standard unit block Equal parts of reference coordinate points The ordinate value; Correction spacing based on the horizontal axis Correction spacing with the ordinate Correcting the first The spacing between the vertices of the twisted equal parts is obtained as the first... The first twisted unit block The coordinates of a twisted, equally divided reference vertex.

6. A laser printer image density correction device, characterized in that, include: The partitioning module is used to divide the print image corresponding to the data to be printed into multiple standard unit blocks; Each of the standard unit blocks comprises multiple standard equal parts; The calculation module is used to place each standard segment in a planar coordinate system, obtain the vertex coordinates of the standard segment in the planar coordinate system, and use the vertex coordinates to determine the reference coordinate point of the standard segment in the planar coordinate system; the planar coordinate system is a two-dimensional rectangular coordinate system constructed with the scanning start point of the laser printer's scanning system as the origin; The scanning module is used to scan the divided printed image to obtain the mapped image; The comparison module is used to compare the printed image and the mapped image to identify the distorted unit blocks in the mapped image. The correction module uses the standard equally divided reference coordinate points in the planar coordinate system to correct the distorted unit blocks in the mapped image, thereby obtaining a density-corrected mapped image. No. The standard unit block corresponding to the twisted unit block is the first twisted unit block of the printed image. The first standard unit block, the first Each twisted unit block contains A distorted equal part; The correction module is specifically used for: Regarding the first The first twisted unit block A distorted equal part, if no The element in the middle column is then determined using the method described above. The standard divisions of each standard unit block are reference coordinate points in the planar coordinate system to obtain the first... The first twisted unit block The coordinates of a twisted, equally divided reference vertex; A standard equally divided index matrix containing One element, , ; like yes The element in the middle column is then determined using the method described above. In the twisted unit block, with the first The coordinates of the reference vertices of the adjacent twisted equal parts are obtained to obtain the first twisted equal parts. The coordinates of a twisted, equally divided reference vertex; Based on the The first twisted unit block The first distorted equal-part reference vertex coordinate correction The first twisted unit block The coordinates of the distorted, equally divided vertex; Among them, if If the total number of columns is even, then The middle column is the two middle columns, if If the total number of columns is odd, then The middle column is the very middle column.

7. A laser printer, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the image density correction method as described in any one of claims 1 to 5.

8. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the image density correction method as described in any one of claims 1 to 5.

Images