TW201939936A - Image processing device - Google Patents

Abstract

An image processing device includes a receiving unit, a correction unit, a calculating unit, and an assignment unit. The receiving unit receives input values of a first pixel and a second pixel. The correction unit calculates a correction value of the first pixel according to plural error component values of plural first neighboring pixels of the first pixel and the input value of the first pixel, and calculates a correction value of the second pixel according to plural error component values of plural second neighboring pixels of the second pixel and the input value of the second pixel. The calculating unit calculates output values of the first pixel and the second pixel according to the correction values of the first pixel and the second pixel, respectively. The assignment unit assigns the output values of the first pixel and the second pixel to the first pixel and the second pixel, respectively.

Description

Image processing device

The embodiments of the present disclosure relate to an image processing apparatus, and more particularly, to an image processing apparatus based on error diffusion and improved.

The quantization processing of image pixel values is a common technique in image processing. However, the quantization processing usually causes a quantization error of the image pixel values. In order to prevent the image from feeling obvious differences due to these quantization errors, error diffusion processing technology is a common halftone image processing technology. Error diffusion processing technology The quantization error of a pixel is distributed to neighboring pixels, thereby dispersing the quantization error. Compared with other halftone image processing technologies, error diffusion processing technology has considerable advantages in reconciling halftone image quality and image processing efficiency.

For example, one of the conventional error diffusion processing methods is to diffuse errors to pixels on the right (horizontal diffusion) and pixels below (vertical diffusion). However, the horizontal diffusion method is disadvantageous to the hardware, such as high hardware design cost, limited information processing capacity, and insufficient transmission timing. Therefore, the conventional error diffusion processing method still has room for improvement.

The purpose of this disclosure is to propose an image processing device that is based on error diffusion and is improved to improve the shortcomings of the conventional error diffusion processing method.

According to the above purpose of the present disclosure, an image processing apparatus is provided, which includes: an input value receiving unit, a correction value calculating unit, an output value calculating unit, and an output value specifying unit. The input value receiving unit is configured to receive an input value of a first pixel and an input value of a second pixel of the image, wherein the first pixel is adjacent to the second pixel, and the first pixel and the second pixel are respectively located at the first position (x , y) and the second position (x + 1, y). The correction value calculation unit is configured to calculate the correction value of the first pixel according to the component error values of the first adjacent pixels adjacent to the first pixel and the input value of the first pixel, and to calculate the correction value of the first pixel according to A plurality of component error values of a plurality of second adjacent pixels of the pixel and an input value of the second pixel are used to calculate a correction value of the second pixel, wherein the plurality of first adjacent pixels are respectively located at a third position (x-1, y), fourth position (x-1, y-1), fifth position (x, y-1), and sixth position (x + 1, y-1), where a plurality of second adjacent pixels are respectively It is located at the fifth position (x, y-1), the sixth position (x + 1, y-1), and the seventh position (x + 2, y-1). The output value calculation unit is configured to calculate the output value of the first pixel according to the correction value of the first pixel, and calculate the output value of the second pixel according to the correction value of the second pixel. The output value specifying unit is used to specify an output value of the first pixel to the first pixel, and specify an output value of the second pixel to the second pixel.

In some embodiments, the correction value of the first pixel is a value between a plurality of component error values of a plurality of first neighboring pixels and an input value of the first pixel. In sum, the correction value of the second pixel is the sum of the component error values of the plurality of second neighboring pixels and the input value of the second pixel.

In some embodiments, the output value of the first pixel is the most significant bit (MSB) value of the correction value of the first pixel, and the output value of the second pixel is the highest value of the correction value of the second pixel. Significant bit value.

In some embodiments, the image processing apparatus further includes an error value calculation unit for calculating the error value of the first pixel according to the correction value of the first pixel, and calculating the error value of the second pixel according to the correction value of the second pixel. value.

In some embodiments, the error value of the first pixel is the least significant bit (LSB) value of the correction value of the first pixel, and the error value of the second pixel is the least correction value of the second pixel. Significant bit value.

In some embodiments, the component error value of the first neighboring pixel located at the third position (x-1, y) is A of the error value of the first neighboring pixel located at the third position (x-1, y). / Z; the component error value of the first neighboring pixel at the fourth position (x-1, y-1) is the error value of the first neighboring pixel at the fourth position (x-1, y-1) B / Z; the component error value of the first neighboring pixel at the fifth position (x, y-1) is the C / Z of the error value of the first neighboring pixel at the fifth position (x, y-1) ; The component error value of the first neighboring pixel at the sixth position (x + 1, y-1) is the D / of the error value of the first neighboring pixel at the sixth position (x + 1, y-1) Z; the component error value of the second adjacent pixel at the fifth position (x, y-1) is the error value of the second adjacent pixel at the fifth position (x, y-1) E / Z; the component error value of the second neighboring pixel at the sixth position (x + 1, y-1) is the error value of the second neighboring pixel at the sixth position (x + 1, y-1) F / Z; the component error value of the second neighboring pixel at the seventh position (x + 2, y-1) is the error of the second neighboring pixel at the seventh position (x + 2, y-1) Value G / Z; where A, B, C, D, E, F, G, Z are positive integers, and A + B + C + D + E + F + G = 2 * Z.

In some embodiments, A = 7, B = 3, C = 6, D = 1, E = F = G = 5.

In some embodiments, the error value of the first adjacent pixel is the least significant bit (LSB) value of the correction value of the first adjacent pixel, and the error value of the second adjacent pixel is the second Least significant bit value of the correction value of adjacent pixels.

In some embodiments, the first adjacent pixel located at the fifth position (x, y-1) and the second adjacent pixel located at the fifth position (x, y-1) are the same pixel and located at the sixth position ( The first adjacent pixel at x + 1, y-1) and the second adjacent pixel at the sixth position (x + 1, y-1) are the same pixel.

In order to make the above-mentioned features and advantages of the present disclosure more comprehensible, embodiments are described below in detail with reference to the accompanying drawings.

100‧‧‧Image processing device

110‧‧‧input value receiving unit

120‧‧‧correction value calculation unit

130‧‧‧output value calculation unit

140‧‧‧Output value specifying unit

150‧‧‧ Error value calculation unit

E ₃ , E ₄ , E ₅ , E ₆ , E ₇ ‧‧‧ error value

I ₁ , I ₂ ‧‧‧ Input value

P (x, y) ‧‧‧first pixel

P (x + 1, y) ‧‧‧ second pixel

P (x-1, y), P (x-1, y-1) ‧‧‧First adjacent pixel

P (x + 2, y-1) ‧‧‧Second adjacent pixel

P (x, y-1), P (x + 1, y-1) ‧‧‧first neighboring pixel / second neighboring pixel

A better understanding of the aspects of the present disclosure can be obtained from the following detailed description in conjunction with the accompanying drawings. It should be noted that, according to industry standard practice, features are not drawn to scale. In fact, to make the discussion clearer, the dimensions of each feature can be arbitrarily increased or decreased.

[FIG. 1] A system block diagram of an image processing device according to an embodiment of the present disclosure.

FIG. 2 is a schematic diagram of a pixel configuration according to an embodiment of the disclosure.

3 is a schematic diagram of diffusion of component error values of first neighboring pixels according to an embodiment of the disclosure.

FIG. 4 is a schematic diagram of diffusion of component error values of a second neighboring pixel according to an embodiment of the disclosure.

Embodiments of the invention are discussed in detail below. It is understood, however, that the embodiments provide many applicable concepts that can be embodied in a wide variety of specific content. The embodiments discussed and disclosed are for illustration only and are not intended to limit the scope of the invention.

FIG. 1 is a system block diagram of an image processing apparatus 100 according to an embodiment of the present disclosure. FIG. 2 is a schematic diagram of a pixel configuration according to an embodiment of the disclosure. Here, the meaning represented by the symbols in FIG. 2 is first defined, for example, the pixel at the position (x, y) is represented by P (x, y), and so on. 1 and FIG. 2 together, the image processing apparatus 100 includes a step input value receiving unit 110, a correction value calculating unit 120, an output value calculating unit 130, an output value specifying unit 140, and an error value calculating unit 150. The first pixel P 110 receives an input value of an image receiving unit (x, y) of the input value I ₁ and the second pixel P (x + 1, y) of the input value I _2. For example, the input value I ₁ of the first pixel P (x, y) is the pixel data of the first pixel P (x, y) in the received image, and the second pixel P (x + 1, y) is the The input value I ₂ is the pixel data of the second pixel P (x + 1, y) in the received image.

The correction value calculation unit 120 is configured to calculate a component error value EC ₁₁ adjacent to the first pixel P (x-1, y) adjacent to the first pixel P (x, y) , y) component error value EC ₁₂ of the first neighboring pixel P (x-1, y-1), and the first neighboring pixel P (x, y- 1) the error component EC _13, a first adjacent pixel adjacent to the first pixel P (x, y) of P (x + 1, y- 1) component of the first error value and the EC ₁₄ pixel P (x , y) of the input value I ₁ calculates a first pixel P (x, y) of the correction value D _1.

In the embodiment of the present disclosure, the correction value D ₁ of the first pixel P (x, y) is the first neighboring pixel P (x-1, y), P (x-1, y-1), P ( x, y-1), P (x + 1, y-1) component error values EC ₁₁ , EC ₁₂ , EC ₁₃ , EC ₁₄ and I ₁ of the input value of the first pixel P (x, y) The sum is D ₁ = I ₁ + (EC ₁₁ + EC ₁₂ + EC ₁₃ + EC ₁₄ ).

The correction value calculation unit 120 is also used to calculate the component error value EC ₂₁ of the second adjacent pixel P (x, y-1) adjacent to the second pixel P (x + 1, y) and the second pixel adjacent to the second pixel P (x + 1, y). The component error value EC ₂₂ of the second neighboring pixel P (x + 1, y-1) of P (x + 1, y) and the second neighboring pixel P (x + 1, y) of the second neighboring pixel The component error value EC _{23 of the} pixel P (x + 2, y-1) and the input value I ₂ of the second pixel P (x + 1, y) are used to calculate the correction value of the second pixel P (x + 1, y) D ₂ .

In the embodiment of the present disclosure, the correction value D ₂ of the second pixel P (x + 1, y) is the second neighboring pixel P (x, y-1), P (x + 1, y-1), The sum of I _{2 of the} component error values EC ₂₁ , EC ₂₂ , EC _{23 of} P (x + 2, y-1) and the input value of the second pixel P (x + 1, y), that is, D ₂ = I ₂ + (EC ₂₁ + EC ₂₂ + EC ₂₃ ).

In the embodiment of the present disclosure, the component error value EC ₁₁ of the first neighboring pixel P (x-1, y) is A / Z of the error value E ₃ of the first neighboring pixel P (x-1, y). , which is ; The component error value EC ₁₂ of the first neighboring pixel P (x-1, y-1) is the B / Z of the error value E ₄ of the first neighboring pixel P (x-1, y-1), that is, ; The component error value EC ₁₃ of the first neighboring pixel P (x, y-1) is the C / Z of the error value E ₅ of the first neighboring pixel P (x, y-1), that is, ; The component error value EC ₁₄ of the first neighboring pixel P (x + 1, y-1) is the D / Z of the error value E ₆ of the first neighboring pixel P (x + 1, y-1), that is, ; The component error value EC ₂₁ of the second neighboring pixel P (x, y-1) is the E / Z of the error value E ₅ of the second neighboring pixel P (x, y-1), that is, ; The component error value EC ₂₂ of the second neighboring pixel P (x + 1, y-1) is the F / Z of the error value E ₆ of the second neighboring pixel P (x + 1, y-1), that is, ; The component error value EC ₂₃ of the second neighboring pixel P (x + 2, y-1) is the G / Z of the error value E ₇ of the second neighboring pixel P (x + 2, y-1), that is, . Where A, B, C, D, E, F, G, Z are positive integers, and A + B + C + D + E + F + G = 2 * Z.

FIG. 3 is a schematic diagram of diffusion of component error values of a first adjacent pixel of a first pixel P (x, y) according to an embodiment of the disclosure. In an embodiment of the present disclosure, A = 7, B = 3, C = 6, D = 1, Z = 16. in particular, ; ; ; . However, this disclosure is not limited to this.

FIG. 4 is a schematic diagram of diffusion of component error values of a second adjacent pixel of a second pixel P (x + 1, y) according to an embodiment of the disclosure. In one embodiment of the present disclosure, E = F = G = 5 and Z = 16. in particular, ; ; . However, this disclosure is not limited to this.

The output value calculation unit 130 is configured to calculate the output value O _{1 of the} first pixel P (x, y) according to the correction value D ₁ of the first pixel P (x, y), and according to the second pixel P (x + 1, The correction value D _{2 of} y) is used to calculate the output value O _{2 of the} second pixel P (x + 1, y). In the embodiment of the present disclosure, the output value O ₁ of the first pixel P (x, y) is the most significant bit (MSB) value of the correction value D ₁ of the first pixel P (x, y). , That is, O ₁ = MSB (D ₁ ). In the embodiment of the present disclosure, the output value O ₂ of the second pixel P (x + 1, y) is the most significant bit value of the correction value D ₂ of the second pixel P (x + 1, y), that is, O ₂ = MSB (D ₂ ).

The error value calculation unit 150 is configured to calculate the error value E _{1 of the} first pixel P (x, y) according to the correction value D ₁ of the first pixel P (x, y), and according to the second pixel P (x + 1, The correction value D _{2 of} y) is used to calculate the error value E _{2 of the} second pixel P (x + 1, y). In the embodiment of the present disclosure, the error value E ₁ of the first pixel P (x, y) is the least significant bit (LSB) value of the correction value D ₁ of the first pixel P (x, y). , That is, E ₁ = LSB (D ₁ ). In the embodiment of the present disclosure, the error value E ₂ of the second pixel P (x + 1, y) is the least significant bit value of the correction value D ₂ of the second pixel P (x + 1, y), that is, E ₂ = LSB (D ₂ ). It is worth mentioning that the first pixel P (x, y) of the error value calculation unit 150 calculates the error value E ₁ and the second pixel P (x + 1, y) of the same error value E ₂ will be according to the above Way to diffuse to its neighboring pixels.

In the embodiment of the present disclosure, the error value E ₃ of the first neighboring pixel P (x-1, y) is the least significant bit of the correction value D ₃ of the first neighboring pixel P (x-1, y). Value, that is, E ₃ = LSB (D ₃ ); the error value E ₄ of the first neighboring pixel P (x-1, y-1) is the correction of the first neighboring pixel P (x-1, y-1) The least significant bit value of the value D ₄ is E ₄ = LSB (D ₄ ); the error value E ₅ of the first adjacent pixel (or the second adjacent pixel) P (x, y-1) is the first phase The least significant bit value of the correction value D ₅ of the neighboring pixel P (x, y-1), that is, E ₅ = LSB (D ₅ ); the first neighboring pixel (or the second neighboring pixel) P (x + 1 , y-1) error value E ₆ is the least significant bit value of the correction value D ₆ of the first neighboring pixel P (x + 1, y-1), that is, E ₆ = LSB (D ₆ ); second The error value E ₇ of the adjacent pixel P (x + 2, y-1) is the least significant bit value of the correction value D ₇ of the second adjacent pixel P (x + 2, y-1), that is, E ₇ = LSB (D ₇ ). It is worth mentioning that, because the correction value calculation unit 120 is, for example, calculating the correction value of the first pixel based on the multiple component error values of the plurality of first neighboring pixels and the input value of the first pixel, it is shown in FIG. In the system block diagram shown, the error value calculated by the error value calculation unit 150 is sent back to the correction value calculation unit 120 to calculate the correction value.

The output value specifying unit 140 is used to specify an output value O _{1 of} the first pixel P (x, y) to the first pixel P (x, y), and specify an output value O of the second pixel P (x + 1, y). ₂ for the second pixel P (x + 1, y). For example, the output value O ₁ of the first pixel P (x, y) is the pixel data of the first pixel P (x, y) in the output image, and the output value of the second pixel P (x + 1, y) is The output value O ₂ is the pixel data of the second pixel P (x + 1, y) in the output image.

It is worth mentioning that in the embodiment of the present disclosure, when at least one of the first pixel P (x, y) and the second pixel P (x + 1, y) is located at the edge of the image, the first In the case where at least one of a neighboring pixel and a second neighboring pixel does not substantially exist, if this is the case, the original pixel data of the nearest and substantially existing pixel is designated as the non-existing first phase Neighbor The original pixel data of the prime or second neighboring pixel. For example, when the first pixel P (x, y) is at the far left of the image, the first neighboring pixel P (x-1, y) does not exist substantially, so it will be closest to the first neighboring pixel P (x-1, y) and the original pixel data of the substantially existing pixel (that is, the first pixel P (x, y)) is designated as the original pixel data of the first neighboring pixel P (x-1, y). By analogy, the rest of the cases (for example, the leftmost side of the image at the second pixel P (x + 1, y) position, etc.) are also the same, and will not be repeated here.

It should be noted that, for the first adjacent pixel of the embodiment of the present disclosure, it includes horizontal diffusion and vertical diffusion, and for the second adjacent pixel of the embodiment of the present disclosure, there is only vertical diffusion. Specifically, for the image processing apparatus 100 according to the embodiment of the disclosure, only half of the pixels will diffuse their component error values horizontally and vertically, and the other half of the pixels will only have their component errors Values are diffused vertically. Therefore, compared to the conventional error diffusion processing method, the image processing apparatus 100 of the embodiment of the present disclosure has the following benefits: it can reduce the cost of hardware design, increase the amount of output information processing, and speed up the transmission sequence.

In summary, the present disclosure proposes an image processing device based on error diffusion and improving it, thereby improving the shortcomings of the conventional error diffusion processing method.

The features of several embodiments are summarized above, so those skilled in the art can better understand the aspects of the present disclosure. Those skilled in the art should understand that they can easily use this disclosure as a basis to design or modify other processes and structures, thereby achieving the same goals and / or achieving the same advantages as the embodiments described herein. . Those skilled in the art should also understand that these equivalent constructs Structures do not depart from the spirit and scope of this disclosure, and they can make various changes, substitutions, and alterations without departing from the spirit and scope of this disclosure.

Claims (9)

An image processing device includes: an input value receiving unit for receiving an input value of a first pixel of an image and an input value of a second pixel, wherein the first pixel is adjacent to the second pixel, The first pixel and the second pixel are respectively located at a first position (x, y) and a second position (x + 1, y); a correction value calculating unit is configured to A plurality of component error values of a plurality of first adjacent pixels of the pixel and the input value of the first pixel to calculate a correction value of the first pixel, and according to a plurality of second phases adjacent to the second pixel A plurality of component error values of adjacent pixels and the input value of the second pixel are used to calculate a correction value of the second pixel, wherein the first adjacent pixels are respectively located at a third position (x-1, y) A fourth position (x-1, y-1), a fifth position (x, y-1), and a sixth position (x + 1, y-1), wherein the second adjacent pixels are Located at the fifth position (x, y-1), the sixth position (x + 1, y-1), and a seventh position (x + 2, y-1), respectively; an output value calculation unit for The school according to the first pixel Value to calculate an output value of the first pixel, and calculate an output value of the second pixel according to the correction value of the second pixel; and an output value specifying unit for specifying the output of the first pixel Value to the first pixel, and assign the output value of the second pixel to the second pixel. The image processing device according to item 1 of the scope of patent application, wherein the correction value of the first pixel is a sum of the component error values of the first neighboring pixels and the input value of the first pixel, where The correction value of the second pixel is the sum of the component error values of the second neighboring pixels and the input value of the second pixel. The image processing device according to item 1 of the scope of patent application, wherein the output value of the first pixel is one of the most significant bit (MSB) values of the correction value of the first pixel, wherein the first pixel The output value of the two pixels is one of the most significant bit values of the correction value of the second pixel. The image processing device according to item 1 of the scope of patent application, further comprising: an error value calculating unit for calculating an error value of the first pixel according to the correction value of the first pixel, and according to the second The correction value of the pixel is used to calculate an error value of the second pixel. The image processing device according to item 4 of the scope of patent application, wherein the error value of the first pixel is one of the least significant bit (LSB) values of the correction value of the first pixel, The error value of the second pixel is one of the least significant bit values of the correction value of the second pixel. The image processing device according to item 1 of the scope of patent application, wherein the component error value of the first adjacent pixel located at the third position (x-1, y) is located at the third position (x-1, y) A / Z of an error value of the first neighboring pixel; wherein the component error value of the first neighboring pixel at the fourth position (x-1, y-1) is located at the fourth A B / Z of an error value of the first neighboring pixel at position (x-1, y-1); wherein the component error of the first neighboring pixel at the fifth position (x, y-1) The value is the C / Z of the error value of one of the first neighboring pixels at the fifth position (x, y-1); wherein the first phase at the sixth position (x + 1, y-1) The component error value of the neighboring pixel is the D / Z of the error value of one of the first neighboring pixels at the sixth position (x + 1, y-1); wherein the fifth position (x, y-1) The component error value of the second neighboring pixel is the E / Z of the error value of one of the second neighboring pixels located at the fifth position (x, y-1); where the sixth position (x The component error value of the second neighboring pixel at + 1, y-1) is one of the second neighboring pixels at the sixth position (x + 1, y-1) F / Z of the error value; where the second adjacent pixel at the seventh position (x + 2, y-1) The component error value is G / Z of the error value of one of the second adjacent pixels at the seventh position (x + 2, y-1); where A, B, C, D, E, F, G, Z is a positive integer, and A + B + C + D + E + F + G = 2 * Z. The image processing device according to item 6 of the scope of patent application, wherein A = 7, B = 3, C = 6, D = 1, E = F = G = 5. The image processing device according to item 6 of the scope of patent application, wherein the error value of the first neighboring pixel is one of the least significant bit (LSB) values of the correction value of the first neighboring pixel. , Wherein the error value of the second adjacent pixel is one of the least significant bit values of the correction value of the second adjacent pixel. The image processing device according to item 1 of the scope of patent application, wherein the first adjacent pixel at the fifth position (x, y-1) and the first adjacent pixel at the fifth position (x, y-1) Two adjacent pixels are the same pixel, wherein the first adjacent pixel at the sixth position (x + 1, y-1) and the second phase at the sixth position (x + 1, y-1) Adjacent pixels are the same pixel.