Method for enhancing image quality of locally amplified video area in narrowband environment

Abstract

The invention discloses a method for enhancing the image quality of a locally-amplified video area in a narrow-band environment, and the method comprises the following steps: a front-end player recognizes a rectangular area selected by a user, and transmits the resolution of the player, the coordinates of a pixel point at the upper left corner and a pixel point at the lower right corner of the rectangular area selected by the user, and the id of a video to a rear end; when the rear end obtains the data transmitted by the front end, a corresponding video is found through the video id in the transmitted data, and the resolution ratio of the player and the coordinates of the pixel points of the rectangular area selected by the user are transmitted to the coding end together for processing; and when the coding end receives the coordinate information of the rectangular region selected by the user, carrying out a region coding process on the rectangular region selected by the user, and obtaining the code stream of the rectangular region selected by the user under the limited bandwidth. According to the invention, under the condition that the bandwidth is limited and under the condition that the occupied bandwidth is not changed or is lower, a certain part of picture selected by a user can be displayed more clearly.

Description

Technical Field

[0001] The present invention belongs to the technical field of video playback, and in particular relates to a method for enhancing the image quality of a locally enlarged video area in a narrowband environment. Background Art

[0002] Narrowband environment refers to the satellite network or the environment with limited network bandwidth. Image quality enhancement means that the image quality is better than before while the occupied bandwidth remains the same or lower.

[0003] Video local zooming means that the user selects a certain area in the video for video zooming. Currently, most video area zooming is a kind of electronic zooming, which sacrifices the image quality to zoom in on a certain area. In many cases, after zooming in on the picture, the user cannot clearly see the content of the selected area, which is not very usable.

[0004] The commonly used video area magnification function in the existing surveillance field is based on electronic magnification. This technology processes and magnifies the specific area selected by the user through a digital image processing algorithm. However, in a narrowband or network bandwidth-limited environment, the bit rate allocation of the specific area is small and the image quality is not clear. After electronic magnification, the area cannot achieve a very clear effect. Summary of the invention

[0005] In view of the above problems, the present invention provides a method for enhancing the image quality of a locally enlarged video area in a narrowband environment, which is used to overcome the limited bandwidth and display a certain part of the picture selected by the user more clearly while keeping the occupied bandwidth unchanged or lower.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A method for enhancing the image quality of a locally enlarged video area in a narrowband environment comprises the following steps:

[0008] The front-end player identifies the rectangular area selected by the user and transmits the player resolution, the coordinates of the upper left corner pixel and the lower right corner pixel of the rectangular area selected by the user, and the video ID to the back-end;

[0009] When the backend obtains the data passed in by the frontend, it finds the corresponding video through the video ID in the passed data, and passes the player resolution and the pixel coordinates of the rectangular area selected by the user to the encoding end for processing;

[0010] When the encoding end receives the coordinate information of the rectangular area selected by the user, it performs a region encoding process on the rectangular area selected by the user to obtain the code stream of the rectangular area selected by the user and under the limited bandwidth.

[0011] In a possible implementation manner, the process of performing specific area encoding on the user selected area includes:

[0012] The encoder senses the resolution of the source video stream and the resolution of the front-end player. If the two resolutions are inconsistent, the encoder calculates the ratio of the width and height of the source video stream to the front-end player, which are recorded as the width scale factor and the height scale factor.

[0013] Multiply the x-coordinate of the upper left corner pixel and the x-coordinate of the lower right corner pixel of the rectangular area selected by the user by the width scale factor, and multiply the y-coordinate of the upper left corner pixel and the y-coordinate of the lower right corner pixel by the height scale factor to obtain the coordinate position of the rectangular area selected by the user at the source video stream resolution;

[0014] The encoder byte-aligns the width and height of the rectangular area;

[0015] The encoding end calls the graphics processing acceleration hardware to perform a cropping operation to obtain the video stream of the rectangular area selected by the user in the front-end player;

[0016] By calculating the ratio of the input size to the output size and selecting the QP value so that the bit rate of the rectangular area selected by the user is slightly lower than the original video bit rate, the QP value is used for encoding to obtain the bit stream of the rectangular area selected by the user under the limited bandwidth.

[0017] In a possible implementation, the encoder senses the resolution of the source video stream and the resolution of the front-end player. The resolution information is contained in the header information of the video stream. By parsing the data of the header information, both the player and the encoder can obtain the resolution information.

[0018] In a possible implementation, the encoder performs byte alignment on the width and height of the rectangular area, including: if the encoding end is in H264 encoding mode, 16-byte alignment is performed, and when the width or height is divided by 16 and there is a remainder, it is automatically rounded up to a multiple of 16.

[0019] In a possible implementation, the encoder performs byte alignment on the width and height of the rectangular area, including: if the encoding end is in H265 encoding mode, 64-byte alignment is performed, and when the width or height is divided by 64 and there is a remainder, it is automatically rounded up to a multiple of 64.

[0020] The present invention has the following beneficial effects:

[0021] (1) Improve user experience: It can provide clearer and more detailed video images in narrowband environments, improving the user's viewing experience.

[0022] (2) Saving bandwidth resources: By locally zooming in on a specific area and enhancing the image quality, network bandwidth resources can be saved while ensuring the overall video transmission quality.

[0023] (3) Wide range of applications: Applicable to video transmission scenarios in various narrowband environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The present invention is a flowchart of a method for enhancing the image quality of a locally enlarged video area in a narrowband environment according to an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Reference Figure 1 , which is a flowchart of a method for enhancing the image quality of a locally enlarged video area in a narrowband environment according to an embodiment of the present invention, includes the following steps:

[0027] S10, the front-end player identifies the rectangular area selected by the user, and transmits the player resolution, the coordinates of the upper left corner pixel and the lower right corner pixel of the rectangular area selected by the user, and the ID of the video to the back-end;

[0028] S20, when the backend obtains the data passed in by the frontend, it finds the corresponding video through the video ID in the passed in data, and passes the player resolution and the pixel coordinates of the rectangular area selected by the user to the encoding end for processing;

[0029] S30, when the encoding end receives the coordinate information of the rectangular area selected by the user, it performs a region encoding process on the rectangular area selected by the user to obtain a code stream of the rectangular area selected by the user under a limited bandwidth.

[0030] In a specific application example, the process of performing specific area encoding on the user selected area in S30 includes:

[0031] The encoder senses the resolution of the source video stream and the resolution of the front-end player. If the two resolutions are inconsistent, the encoder counts the ratios of the width and height of the source video stream and the front-end player respectively, which are recorded as the width scale factor and the height scale factor. The resolution information is contained in the header information of the video stream. By parsing the data of the header information, both the player and the encoder can obtain the resolution information.

[0032] Multiply the x-coordinate of the upper left corner pixel and the x-coordinate of the lower right corner pixel of the rectangular area selected by the user by the width scale factor, and multiply the y-coordinate of the upper left corner pixel and the y-coordinate of the lower right corner pixel by the height scale factor to obtain the coordinate position of the rectangular area selected by the user at the source video stream resolution;

[0033] The encoder byte-aligns the width and height of the rectangular region; alignment ensures that each block can neatly cover each frame without having to deal with boundary conditions. And processing in fixed-size memory blocks can significantly reduce memory access speed and computational complexity.

[0034] The encoding end calls the graphics processing acceleration hardware to perform a cropping operation to obtain the video stream of the rectangular area selected by the user in the front-end player;

[0035] By calculating the ratio of the input size to the output size and selecting the QP value so that the bit rate of the rectangular area selected by the user is slightly lower than the original video bit rate, the QP value is used for encoding to obtain the bit stream of the rectangular area selected by the user under limited bandwidth. The bit rate slightly lower here means within 20%. Generally, lowering one QP will reduce the bit rate by about 12%. QP is the abbreviation of (Quantization Parametr), which reflects the compression of spatial details. The smaller the value, the finer the quantization and the higher the image quality.

[0036] In a specific application embodiment, further, the encoder performs byte alignment on the width and height of the rectangular area, including: if the encoding end is in H264 encoding mode, 16-byte alignment is performed, and when the width or height is divided by 16 and there is a remainder, it is automatically rounded up to a multiple of 16.

[0037] In a specific application embodiment, further, the encoder performs byte alignment on the width and height of the rectangular area, including: if the encoding end is in H265 encoding mode, 64-byte alignment is performed, and when the width or height is divided by 64 and there is a remainder, it is automatically rounded up to a multiple of 64.

[0038] The above-set method for enhancing the image quality of a locally enlarged video area in a narrowband environment performs hardware cropping of the video stream based on the user-selected area of ​​the video stream, and sets a suitable QP for the cropped video stream, so that the cropped bitstream can effectively enhance the image quality of a specific area without exceeding the original bandwidth, thereby ensuring the overall video transmission quality and improving the video viewing experience.

[0039] It should be understood that the exemplary embodiments described herein are illustrative rather than restrictive. Although one or more embodiments of the present invention have been described in conjunction with the accompanying drawings, it should be understood by those skilled in the art that various changes in form and detail may be made without departing from the spirit and scope of the present invention as defined by the appended claims.

Claims

1. A method for enhancing the image quality of a locally enlarged video area in a narrowband environment, characterized in that: The following steps are involved: The front-end player identifies the rectangular area selected by the user and transmits the player resolution, the coordinates of the upper left corner pixel and the lower right corner pixel of the rectangular area selected by the user, and the video ID to the back-end; When the backend obtains the data passed in by the frontend, it finds the corresponding video through the video ID in the passed data, and passes the player resolution and the pixel coordinates of the rectangular area selected by the user to the encoding end for processing; When the encoding end receives the coordinate information of the rectangular area selected by the user, it performs a region encoding process on the rectangular area selected by the user to obtain the code stream of the rectangular area selected by the user and under the limited bandwidth.

2. The method for enhancing the image quality of a locally enlarged video area in a narrowband environment as claimed in claim 1, characterized in that: The process of performing specific area encoding on the area selected by the user includes: The encoder senses the resolution of the source video stream and the resolution of the front-end player. If the two resolutions are inconsistent, the encoder calculates the ratio of the width and height of the source video stream to the front-end player, which are recorded as the width scale factor and the height scale factor. Multiply the x-coordinate of the upper left corner pixel and the x-coordinate of the lower right corner pixel of the rectangular area selected by the user by the width scale factor, and multiply the y-coordinate of the upper left corner pixel and the y-coordinate of the lower right corner pixel by the height scale factor to obtain the coordinate position of the rectangular area selected by the user at the source video stream resolution; The encoder byte-aligns the width and height of the rectangular area; The encoding end calls the graphics processing acceleration hardware to perform a cropping operation to obtain the video stream of the rectangular area selected by the user in the front-end player; By calculating the ratio of the input size to the output size and selecting the QP value so that the bit rate of the rectangular area selected by the user is slightly lower than the original video bit rate, the QP value is used for encoding to obtain the bit stream of the rectangular area selected by the user under the limited bandwidth.

3. The method for enhancing the image quality of a locally enlarged video area in a narrowband environment as claimed in claim 2, characterized in that: The encoder senses the resolution of the source video stream and the resolution of the front-end player. The resolution information is contained in the header information of the video stream. By parsing the data of the header information, both the player and the encoder can obtain the resolution information.

4. The method for enhancing the image quality of a locally enlarged video area in a narrowband environment according to claim 2 or 3, characterized in that: The encoder performs byte alignment on the width and height of the rectangular area, including: if the encoding end is in H264 encoding mode, 16-byte alignment is performed, and when the width or height is divided by 16 and there is a remainder, it is automatically rounded up to a multiple of 16.

5. The method for enhancing the image quality of a locally enlarged video area in a narrowband environment according to claim 2 or 3, characterized in that: The encoder performs byte alignment on the width and height of the rectangular area, including: if the encoding end is in H265 encoding mode, 64-byte alignment is performed, and when the width or height is divided by 64 and there is a remainder, it is automatically rounded up to a multiple of 64.

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