• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.46 no.2
• /
• pp.48-56
• /
• 2009

We propose a fast intra mode skip decision algorithm for H.264/AVC video encoding. Although newly added MB encoding algorithms based on various prediction methods increase compression ratio, they require a significant increase in the computational complexity because we calculate rate-distortion(RD) cost for all possible MB coding modes and then choose the best one. In this paper, we propose a fast mode decision algorithm based on an adaptive motion vector map(AMVM) method for H.264/AVC video encoding to reduce the processing time for the inter frame. We verify that the proposed algorithm generates generally good performances in PSNR, bit rates, and processing time.

• Journal of the Korea Society of Computer and Information
• /
• v.4 no.3
• /
• pp.73-77
• /
• 1999

In this paper. wavelet transform coding for image conference is studied. Original video frames are transformed into hierarchical pyramidal images with multiresolution using the band property of wavelet transform coefficients. Moving information between neighboring frames is obtained from the low-resolution band. Also, to control the video coding procedure. a new picture set filter is proposed. This filter controls the compression ratio of each frame depending on the correlation to the reference frame by selectively eliminating less important high-resolution areas. Consequently. video quality can be preserved and bit rate can be controlled adaptively In the simulation, to test the performance of the proposed coding method, comparisons with the full search block matching algorithm and the differential image coding algorithm are made. Consequently. the proposed method shows a reasonably good performance over existing ones.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.10 no.11
• /
• pp.2020-2025
• /
• 2006

H.264/AVC is newest video coding standard of the ITU-T Video coding Experts Group and the ISO/IEC Moving Picture Expets Group. Recently H.264/AVC has been adopted as a video compression standard in DMB and multimedia equipments. In this paper, we propose a H.264/AVC intra frame decoder which can minimize the memory usage and chip size. The proposed intra frame decoder is described in VHDL language and simulated in model_sim. It was verified in chip level by downloading to XCV1000E FPGA chip.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2010.05a
• /
• pp.614-616
• /
• 2010

Recently, there is increasing concern about smart phone due to the release of iPhone and Android phone. So, There are many kinds of application in smart phone, and applications using multimedia contents is increasing. The famous codecs for Image and video are JPEG, MPEG and h.264, which is popular recently as a vedeo codec because of its high compression ratio compared with the other video codecs. In this paper, we will divide Jpeg Sequence to each Jpeg and will display that Jpeg looks like a video continuously in Android. And we will show you the simulation result.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2010.05a
• /
• pp.585-588
• /
• 2010

Recently, there is increasing concern about smart phone due to the release of Iphone and Android phone. Like the normal desktop application, using multimedia contents will have important role for smart phone application. The multimedia contents mentioned here mean Image and Video. The famous codecs for Image and video are Jpeg Mpeg and h.264, which is popular recently as a vedeo codec because of its high compression ratio compared with the other video codecs. In this paper, we will use Jpeg and H.264 encoded raw sequences. This paper will suggest how to decode and display effectively Jpeg and H.264 raw sequences arrived from socket stream. And we will show you the simulation result.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2019.06a
• /
• pp.222-224
• /
• 2019

Light Field (LF) camera captures not only the light intensity but also the light direction coming to camera. While the rich information captured by LF camera enables many interesting applications such as digital refocusing, viewpoint changing, and 3D reconstruction, but it also requires powerful coding tools to reduce its large volume of data. In this paper, we investigate using the intra prediction scheme of the versatile video coding (VVC), which is the most recent video coding technology currently under developing, to compress the LF image. The Intra Block Copy (IBC) technique in VVC is exploited considering special LF image structure. The experimental result shows that VVC intra predict ion outperforms the H.265/HEVC intra coding technique in encoding LF data irrespective of using the IBC mode or not.

• Journal of Broadcast Engineering
• /
• v.24 no.1
• /
• pp.97-104
• /
• 2019

In the field of video watermarking, which adds a time axis to the watermarking of the existing still image, it is important to embed a watermark at a level that can claim copyright while minimizing the overall video quality. In this paper, we focus on the fact that B slices refer to blocks of I and P slices in the Random Access compression method of HEVC. Therefore, We propose that watermark is embedded only in I and P slices and extracted in I, P, and B slices. This can minimize the decreases of the overall image quality of the image and protect the copyright of the B slice without directly embedding the watermark.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.23 no.1
• /
• pp.37-43
• /
• 2023

Compressed still image or video bitstreams require protection from channel errors in a wireless channel. Embedded Zerotree Coding(EZW), SPIHT could have provided unprecedented high performance in image compression with low complexity. If bit error is generated by dint of wireless channel transmission problem, the loss of synchronization on between encoder and decoder causes serious performance degradation. But wavelet zerotree coding algorithms are producing variable-length codewords, extremely sensitive to bit errors. The idea is to partition the lifting coefficients. A many partition of lifting transform coefficients distributes channel error from wireless channel to each partition. Therefore synchronization problem that caused quality deterioration in still image and video stream was improved.

• Journal of Broadcast Engineering
• /
• v.27 no.6
• /
• pp.861-871
• /
• 2022

The moving picture experts group (MPEG) developed the MPEG immersive video (MIV) standard for efficient compression of multiple immersive videos representing natural contents and computer graphics. The MIV compresses multiple immersive videos and generates multiple output videos which are defined as atlases. However, there is a synchronization issue of multiple decoders in a legacy device when decoding multiple encoded atlases. This paper proposes and implements the geometry packing method for adaptive control of decoder instances for low-end and high-end devices. The proposed method on the recent version of the MIV reference software worked correctly.

• Journal of Korea Multimedia Society
• /
• v.12 no.7
• /
• pp.913-921
• /
• 2009

Quantization is an essential method for compression of video. The quantizer can adjust the bitrate and control the picture quality. Especially, the subjective picture quality can be improved if the concerned region within a video sequence has good picture quality. In this paper, firstly a classification method according to the subjective concerned region within the video sequence is suggested. Also we propose a method that assigns the quantization step-size differentially according to the concerned region within the video. Totally subjective picture quality can be increased by appling the quantization step-size as small value relatively for the concerned region compared with the other regions. We can find the result that the proposed method gives the improved picture quality by assigning differently quantization step-size and the best improvement can be brought when the difference between maximum and minimum values of the quantization step-size in a picture is from 4 to 8.