A sharpness quantification method, storage medium, and terminal device

Abstract

This invention discloses a sharpness quantification method, storage medium, and terminal device. The method includes: acquiring a test screen set of a device under test, wherein the test screen set includes several test screens, each test screen having stripes with periodic brightness variations; for each test screen, acquiring a first brightness of the test screen, and acquiring a sharpness gain coefficient corresponding to the test screen based on the first brightness and a preset second brightness corresponding to the test screen; and determining the sharpness gain coefficient of the device under test based on all acquired sharpness gain coefficients. This invention, by pre-setting a test screen set for the test device, and then acquiring the first brightness of each test screen and obtaining the sharpness gain coefficient of the device under test based on the first brightness and the preset second brightness corresponding to the test screen, facilitates subsequent analysis of the test device and improves the accuracy of the analysis.

Description

Technical Field

[0001] This invention relates to the field of computer technology, and in particular to a sharpness quantification method, storage medium, and terminal device. Background Technology

[0002] Sharpness is one of the most important factors in measuring image quality, reflecting the amount of detail in an image. Sharpness is defined by the boundaries between different tones or color areas. Currently, most companies use subjective human reading as the standard; however, different people's readings, as well as variations in their states of mind, can lead to inconsistencies in reading values.

[0003] Therefore, existing technologies still need to be improved and enhanced. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a sharpness quantification method, storage medium, and terminal device to solve the problem that existing technologies require subjective determination of sharpness values.

[0005] The technical solution adopted in this invention is as follows:

[0006] In a first aspect, the present invention provides a sharpness measurement method, comprising:

[0007] Acquire a set of test screens for the device under test, wherein the set of test screens includes several test screens, each test screen having stripes with periodic brightness variations;

[0008] For each test screen, obtain the first brightness of the test screen, and obtain the sharpness gain coefficient corresponding to the test screen based on the first brightness and the preset second brightness corresponding to the test screen.

[0009] Based on all the obtained sharpness gain coefficients, determine the sharpness gain coefficient of the device under test.

[0010] As a further improved technical solution, the test screen set includes several test screen groups, each test screen group corresponds to a test direction, and the test directions corresponding to each test screen group are different from each other. The time width corresponding to each test screen in each test screen group is different from each other.

[0011] As a further improved technical solution, the stripes corresponding to each test screen are rectangular; the stripe tilt angles of each test screen in the plurality of test screen groups are the same, and the stripe tilt angles of the test screens in the test screen groups are different.

[0012] As a further improved technical solution, the step of obtaining a first brightness of each test image and obtaining a sharpness gain coefficient corresponding to the test image based on the first brightness and a preset second brightness corresponding to the test image specifically includes:

[0013] For each test frame, obtain the first brightness of that test frame;

[0014] Obtain a reference image corresponding to the test image, and obtain a preset second brightness corresponding to the test image based on the brightness of the reference image;

[0015] The sharpness gain coefficient corresponding to the test image is obtained based on the first brightness and the preset second brightness.

[0016] As a further improved technical solution, the amplitude of the bright stripes in the test screen is different from that in the reference screen, while the amplitude of the dark stripes is the same, and the time width of the bright stripes is the same, and the time width of the dark stripes is the same.

[0017] As a further improved technical solution, the time width of the bright and dark stripes is determined by the time width of one pixel and the pixel value of the test image.

[0018] As a further improved technical solution, the step of obtaining the sharpness gain coefficient corresponding to the test image based on the first brightness and the preset second brightness corresponding to the test image specifically involves:

[0019] Calculate the ratio of the first brightness to the second brightness, and use the ratio as the sharpness gain coefficient corresponding to the test image.

[0020] As a further improved technical solution, after determining the sharpness gain coefficient of the device under test based on all the obtained sharpness gain coefficients, the method further includes:

[0021] The obtained sharpness gain coefficients are plotted as a curve.

[0022] In a second aspect, the present invention provides a computer-readable storage medium storing one or more programs that can be executed by one or more processors to implement the steps in the sharpness quantification method as described in any of the above claims.

[0023] Fourthly, the present invention provides a terminal device comprising: a processor and a memory; the memory storing a computer-readable program executable by the processor; and the processor executing the computer-readable program to implement the steps in the sharpness quantification method described in any of the above.

[0024] Beneficial Effects: Compared with existing technologies, this invention provides a sharpness measurement method, storage medium, and terminal device. The method includes: acquiring a test screen set of a device under test, wherein the test screen set includes several test screens, each test screen having stripes with periodic brightness variations; for each test screen, acquiring a first brightness of the test screen, and acquiring a sharpness gain coefficient corresponding to the test screen based on the first brightness and a preset second brightness corresponding to the test screen; determining the sharpness gain coefficient of the device under test based on all acquired sharpness gain coefficients. This invention, by pre-setting a test screen set for the test device, and then acquiring the first brightness of each test screen and obtaining the sharpness gain coefficient of the device under test based on the first brightness and a preset second brightness corresponding to the test screen, facilitates subsequent analysis of the test device and improves the accuracy of the analysis. Attached Figure Description

[0025] Figure 1 A flowchart of the sharpness quantification method provided by the present invention.

[0026] Figure 2 This is a schematic diagram of the sharpness test screen provided by the present invention.

[0027] Figure 3 This is a schematic diagram of a periodic rectangular wave provided by the present invention.

[0028] Figure 4 The signal diagram of the periodic rectangular wave provided by the present invention.

[0029] Figure 5 The PHT provided by the present invention m and PHR m A schematic diagram of the image.

[0030] Figure 6 PVT provided for the present invention m and PVR m A schematic diagram of the image.

[0031] Figure 7 PDT provided for this invention m and PDR m Illustration of the image

[0032] Figure 8 This is a schematic diagram of a curve provided by the present invention.

[0033] Figure 9 The structural schematic diagram of the terminal device provided by the present invention. Detailed Implementation

[0034] This invention provides a sharpness measurement method, a storage medium, and a terminal device. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention.

[0035] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when we say an element is “connected” or “coupled” to another element, it can be directly connected or coupled to the other element, or there may be intermediate elements. Furthermore, “connected” or “coupled” as used herein can include wireless connections or wireless coupling. The term “and / or” as used herein includes all or any units and all combinations of one or more associated listed items.

[0036] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0037] The invention will be further explained below with reference to the accompanying drawings and the description of the embodiments.

[0038] This embodiment provides a sharpness quantification method, such as Figure 1 As shown, the method includes:

[0039] S100. Obtain the test screen set of the device under test, wherein the test screen set includes several test screens, and each test screen has stripes with periodic brightness changes.

[0040] S200. For each test screen, obtain the first brightness of the test screen, and obtain the sharpness gain coefficient corresponding to the test screen based on the first brightness and the preset second brightness corresponding to the test screen.

[0041] S300. Based on all the obtained sharpness gain coefficients, determine the sharpness gain coefficient of the device under test.

[0042] In this embodiment, by pre-setting the test screen set of the test device, and then by obtaining the first brightness of each test screen, and based on the first brightness and the preset second brightness corresponding to the test screen, the sharpness gain coefficient of the device under test is obtained, which facilitates the subsequent analysis of the test device and improves the accuracy of the analysis.

[0043] In this embodiment, the test screen set includes several test screen groups, each of which corresponds to a test direction, and the test directions corresponding to each test screen group are different. Furthermore, the time width corresponding to each test screen in each test screen group is different. It should be noted that the stripes corresponding to each test screen are rectangular, and in practical applications, the stripe tilt angles of each test screen in the several test screen groups are the same, while the stripe tilt angles of the test screens between different test screen groups are different. For example, the stripe tilt angles in the same test screen group can be 90°, 0°, or 45°. In this embodiment, the stripes with periodic brightness changes can be vertical stripes, horizontal stripes, or diagonal stripes, respectively.

[0044] For example, such as Figure 2 As shown, Figure 2 This is a schematic diagram of the sharpness test screen provided by the present invention. Figure 2 As can be seen, its main characteristic is the presence of stripes with periodic changes in brightness and darkness, while there are no specific regulations regarding their shape, position, size, or direction. Let the angle between the stripes and the horizontal direction be β. For ease of expression, we will use a typical rectangular vertical stripe image (β = 90°) for preliminary analysis.

[0045] Figure 2 The cross-section is a periodic rectangular wave, correspondingly, as... Figure 3 As shown, let the time widths of the dark and bright stripes in each test frame be T1 and T2, respectively, and their amplitudes be Y1 and Y2, respectively. The period is T, the value range of Y1 is [0, Ymax], and the value range of Y2 is [0, Ymax], and the condition 0 ≤ Y1 is satisfied. <Y2≤Ymax。

[0046] Furthermore, the cross-section of each test frame is a periodic rectangular wave, and the Fourier transform of the periodic rectangular wave is as follows:

[0047]

[0048] Where, angular frequency ω=2π / T, Y dc and Y ac These are the coefficients for the DC component and the AC component, respectively.

[0049] Y dc = (T1*Y1+T2*Y2) / (T1+T2);

[0050] Y ac =2*(Y2-Y2) / π.

[0051] The general principle of sharpness enhancement is to first separate the cos(nωt) signals with different frequencies in the signal using a bandpass filter, and then apply different gains A to them. n (A n >1), ultimately synthesized into a sharper signal Y. E .

[0052]

[0053] like Figure 4 As shown, the sharpness enhancement effect of cos(nωt) is as follows. It is easy to see that the changes in the signal are amplified after the sharpness enhancement process, thus making the details of the image clearer and more obvious.

[0054] For example, let Y1 = 0, meaning the dark stripes are completely black. T1 = T2 = T / 2, meaning the time widths of the dark and light stripes are equal. Then we have...

[0055]

[0056] Based on this, a series of images can be designed, incorporating the characteristics of the sharpness test images described above. These images are then enlarged or reduced, and partially or fully displayed on a display device. A luminance meter is then used to test the brightness of the characteristic images, and the corresponding sharpness gain coefficient can be calculated accordingly. The basic parameters of the characteristic images are shown in Table 1.

[0057] Table 1

[0058] Y1 Y2 T1 T2 β PHTm 0 a*Ymax m*τ m*τ 90° PHRm 0 Ymax m*τ m*τ 90° PVTm 0 a*Ymax m*τ m*τ 0° PVRm 0 Ymax m*τ m*τ 0° PDTm 0 a*Ymax m*τ m*τ 45° PDRm 0 Ymax m*τ m*τ 45°

[0059] As shown in Table 1, a is the amplitude coefficient of Y2, 0 < a < 1. Optionally, a equals 0.7, which is A. n (A n >1) Reserved gain control. τ is the time width of one pixel, in seconds per pixel. m = 1, 2, ..., used to characterize the width of the feature image stripes, in pixels. That is, the amplitude of the bright stripes in the test image is different from that in the reference image, while the amplitude of the dark stripes is the same; the time widths of the bright stripes and the dark stripes are the same. Furthermore, the time widths of the bright and dark stripes are determined by the time width of one pixel and the pixel value of the test image.

[0060] In one implementation of this embodiment, for each test screen, obtaining the first brightness of the test screen and obtaining the sharpness gain coefficient corresponding to the test screen according to the first brightness and the preset second brightness corresponding to the test screen specifically includes:

[0061] S201. For each test screen, obtain the first brightness of the test screen;

[0062] S202. Obtain the reference screen corresponding to the test screen, and obtain the preset second brightness corresponding to the test screen according to the brightness of the reference screen;

[0063] S203. According to the first brightness and the preset second brightness, obtain the sharpness gain coefficient corresponding to the test screen.

[0064] In practical applications, the specific method of obtaining the sharpness gain coefficient corresponding to the test screen according to the first brightness and the preset second brightness is:

[0065] Calculate the ratio of the first brightness to the second brightness, and use the ratio as the sharpness gain coefficient corresponding to the test screen.

[0066] Exemplarily, as Figure 5 shown, Figure 5 is a schematic diagram of PHT m and PHR m screens. PHT m is the horizontal sharpness test screen, which is displayed on the display device, and its measured brightness is LHT m ; PHR m is the horizontal sharpness reference screen, which is displayed on the display device, and its measured brightness is LHR m . Under the same conditions, if only sharpness enhancement is considered, according to the above analysis, for PHT m because Y2 - Y1 < Ymax, Y1 will still remain 0, Y2 will be enhanced and become larger, and the overall picture will become brighter. And for PHR m because Y2 - Y1 = Ymax, it will not be affected by sharpness enhancement, then the horizontal sharpness gain coefficient is: AH m = LHT m / LHR m m = 1, 2......

[0067] In one implementation of this embodiment, as Figure 6 shown, Figure 6 is a schematic diagram of PVT m and PVR m screens. PVT m is the vertical sharpness test screen, which is displayed on the display device, and its measured brightness is LVTm PVR m As a reference image for vertical sharpness, it was displayed on a display device, and its brightness was measured to be LVR. m Under the same conditions, if only sharpness enhancement is considered, based on the above analysis, PVT m Because Y2 - Y1 < Ymax, Y1 will remain 0, while Y2 will be enhanced and increased, resulting in an overall brighter image. (PHR) m Since Y2 - Y1 = Ymax, it will not be affected by sharpness enhancement. Therefore, the sharpness gain coefficient in the vertical direction is: AV m =LVT m / LVR m m = 1, 2, ...

[0068] In one implementation of this embodiment, such as Figure 7 As shown, Figure 7 For PDT m and PDR m A diagram of the image. (PDT) m The image was used for a diagonal sharpness test, displayed on a display device, and its brightness was measured in PDR values. m PDR m A diagonal sharpness reference image was displayed on a display device, and its brightness was measured to be LDR. m Under the same conditions, if only sharpness enhancement is considered, based on the above analysis, PDT m Because Y2 - Y1 < Ymax, Y1 will remain 0, while Y2 will be enhanced and increased, resulting in an overall brighter image. (PDR) m Since Y2-Y1=Ymax, it will not be affected by the sharpness enhancement. Therefore, the sharpness gain coefficient in the diagonal direction is: AD m =LVT m / LVR m m = 1, 2, ...

[0069] In summary, AH m AV m and AD m The series of values ​​(m = 1, 2, ...) can be used to characterize the strength of sharpness enhancement in the horizontal, vertical, and diagonal directions, respectively. Let m be 1 to 8, and follow the steps above to obtain AH. m AV m and AD m The series of values ​​are shown in Table 2.

[0070] Table 2

[0071] m 1 2 3 4 5 6 7 8 AHm 0.794 0.892 0.815 0.687 0.661 0.637 0.523 0.519 AVm 0.683 0.753 0.588 0.539 0.522 0.510 0.493 0.499 ADm 0.725 0.811 0.676 0.611 0.589 0.532 0.517 0.503

[0072] Furthermore, in one implementation of this embodiment, after determining the sharpness gain coefficient of the device under test based on all the acquired sharpness gain coefficients, the method further includes: plotting the acquired sharpness gain coefficients into a curve. For example, as shown... Figure 8 As shown, the corresponding AH in the table above m AV m and AD m The series of values ​​(m = 1, 2, ...) can be plotted as a curve to facilitate subsequent analysis of the test equipment and improve the accuracy of the analysis.

[0073] In summary, this invention provides a sharpness measurement method, comprising: acquiring a test screen set of a device under test, wherein the test screen set includes several test screens, each test screen having stripes with periodic brightness variations; for each test screen, acquiring a first brightness of the test screen, and acquiring a sharpness gain coefficient corresponding to the test screen based on the first brightness and a preset second brightness corresponding to the test screen; and determining the sharpness gain coefficient of the device under test based on all acquired sharpness gain coefficients. This invention, by pre-setting a test screen set for the test device, and then acquiring the first brightness of each test screen and obtaining the sharpness gain coefficient of the device under test based on the first brightness and a preset second brightness corresponding to the test screen, facilitates subsequent analysis of the test device and improves the accuracy of the analysis.

[0074] Based on the above-described sharpness quantification method, the present invention also provides a computer-readable storage medium storing one or more programs, which can be executed by one or more processors to implement the steps in the sharpness quantification method described in the above embodiments.

[0075] Based on the above-described sharpness quantification method, the present invention also provides a terminal device, such as... Figure 9 As shown, it includes at least one processor 20; a display screen 21; and a memory 22, and may also include a communications interface 23 and a bus 24. The processor 20, display screen 21, memory 22, and communications interface 23 can communicate with each other via the bus 24. The display screen 21 is configured to display a preset user guide interface in the initial setup mode. The communications interface 23 can transmit information. The processor 20 can invoke logical instructions in the memory 22 to execute the methods described in the above embodiments.

[0076] Furthermore, the logical instructions in the aforementioned memory 22 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium.

[0077] The memory 22, as a computer-readable storage medium, can be configured to store software programs, computer-executable programs, such as program instructions or modules corresponding to the methods in the embodiments of this disclosure. The processor 20 executes functional applications and data processing by running the software programs, instructions, or modules stored in the memory 22, thereby implementing the methods in the above embodiments.

[0078] The memory 22 may include a program storage area and a data storage area. The program storage area may store the operating system and application programs required for at least one function; the data storage area may store data created based on the use of the terminal device. Furthermore, the memory 22 may include high-speed random access memory (RAM) and non-volatile memory. Examples include various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks, as well as transient storage media.

[0079] Furthermore, the specific process of loading and executing multiple instruction processors in the aforementioned storage medium and terminal device has been described in detail in the above method, and will not be repeated here.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A sharpness quantification method, characterized in that, It includes: Acquire a set of test screens for the device under test, wherein the set of test screens includes several test screens, each test screen having stripes with periodic brightness variations; For each test screen, obtain the first brightness of the test screen, and obtain the sharpness gain coefficient corresponding to the test screen based on the first brightness and the preset second brightness corresponding to the test screen. Based on all the obtained sharpness gain coefficients, determine the sharpness gain coefficient of the device under test; The cross-section of the test screen is a periodic rectangular wave, and the Fourier transform of the periodic rectangular wave Y is expressed as: Where, angular frequency ω=2π / T, Y dc and Y ac These are the coefficients for the DC component and the AC component, respectively. AND dc =(T1*Y1+T2*Y2) / (T1+T2),Y ac =2*(Y2-Y1) / π, Y1 and Y2 are the amplitudes of the dark and bright stripes, respectively, and T1 and T2 are the time widths of the dark and bright stripes, respectively. Let Y1 = 0, Y2 = a * Ymax, where a is the reserved gain control, Ymax is the maximum amplitude value, T1 = T2 = m * τ, where τ is the time width of one pixel, and m is the pixel value of the test screen; For each test image, obtaining the first brightness of the test image and, based on the first brightness and a preset second brightness corresponding to the test image, obtaining the sharpness gain coefficient corresponding to the test image specifically includes: For each test frame, obtain the first brightness of that test frame; Obtain a reference image corresponding to the test image, and obtain a preset second brightness corresponding to the test image based on the brightness of the reference image; Based on the first brightness and the preset second brightness, the sharpness gain coefficient corresponding to the test image is obtained; The test screen and the reference screen have different amplitudes for bright stripes and the same amplitude for dark stripes. The bright stripes have the same time width and the dark stripes have the same time width. The specific steps for obtaining the sharpness gain coefficient corresponding to the test image based on the first brightness and the preset second brightness corresponding to the test image are as follows: Calculate the ratio of the first brightness to the second brightness, and use the ratio as the sharpness gain coefficient corresponding to the test image.

2. The sharpness quantification method according to claim 1, characterized in that, The test screen set includes several test screen groups, each test screen group corresponds to a test direction, and the test directions corresponding to each test screen group are different from each other. The time width corresponding to each test screen in each test screen group is different from each other.

3. The sharpness quantification method according to claim 2, characterized in that, The stripes corresponding to each test screen are rectangles; the stripe tilt angles of each test screen in the plurality of test screen groups are the same, while the stripe tilt angles of the test screens in the test screen groups are different.

4. The sharpness quantification method according to claim 1, characterized in that, After determining the sharpness gain coefficient of the device under test based on all the obtained sharpness gain coefficients, the process further includes: The obtained sharpness gain coefficients are plotted as a curve.

5. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores one or more programs, which can be executed by one or more processors to implement the steps in the sharpness quantification method as described in any one of claims 1 to 4.

6. A terminal device, characterized in that, include: Processor and memory; The memory stores a computer-readable program that can be executed by the processor; when the processor executes the computer-readable program, it implements the steps in the sharpness quantification method as described in any one of claims 1 to 4.

Images