China
Africa
Explore chapters and articles related to this topic
Wavelet Transform for Image Coding: JPEG2000
Published in Yun-Qing Shi, Huifang Sun, Image and Video Compression for Multimedia Engineering, 2019
Most image coding standards have exploited the DCT as their core technology for image decomposition for a while. However, this has been changing. The wavelet transform has been adopted by MPEG-4 for still image coding [mpeg4]. Also, JPEG-2000 has used the wavelet transform as its core technology for the next generation of the still image coding standard [jpeg2000 vm]. This is because the wavelet transform can provide not only excellent coding efficiency, but also good spatial and quality scalable functionality. JPEG-2000 is a new type of image compression system under development by Joint Photographic Experts Group for still image coding. This standard is intended to meet a need for image compression with great flexibility and efficient interchangeability. JPEG-2000 is also intended to offer unprecedented access into the image while still in compressed domain. Thus, images can be accessed, manipulated, edited, transmitted, and stored in a compressed form.
Accessing earth observation data using JPEG2000
Published in João Manuel, R. S. Tavares, R. M. Natal Jorge, Computational Modelling of Objects Represented in Images, 2018
Hélder Carvalho, Carlos Serrão, António Serra, Miguel Dias
JPEG2000 introduces flexibility in the transmission of images with a progressive improvement in image quality. The standard supports the capability of transmitting arbitrary regions of interest inside the image, with greater fidelity than others. It is also capable of providing lower resolution and/or low quality representations of an image for quick viewing, by only decoding a selected portion of the total transmitted image. JPEG2000 is able to code a wide range of images, from black and white, to grayscale, full-color (24 bit/pixel) images, to hyper-spectral space and planetary images that typically contain several dozen-color bands (Taubman, David S. & Marcellin, Michael W. 2001). Another important feature is the ability to provide error-resilience during transmission; that is to say, an error during progressive transmission will only affect a small portion of the final image rather than the whole image. As it stands currently, an image than has been compressed to the same final size with JPEG2000 and JPEG, will show much less visible artifacts with the first, due to the increased ability of wavelets to represent an image at low resolution than with the later, where the individual 8x8 blocks become noticeable for large compression ratios (Fig. 1). The two formats behave similarly for high quality reproductions but JPEG2000 increasingly outperforms JPEG as more and more compression is introduced, while maintaining the same visual fidelity (Taubman, David S. & Marcellin, Michael W. 2001).
Emerging Multimedia Standards
Published in Ling Guan, Yifeng He, Sun-Yuan Kung, Multimedia Image and Video Processing, 2012
JPEG-2000 is also the standard for still image coding, which is also jointly developed by ISO/IEC and ITU-T in 2001 as the international standard ISO/IEC 15444-1 or ITU-T Recommendation T.800 [36,37]. The reason to develop JPEG-2000 is to meet some advanced requirements of many of today’s applications such as Internet, wireless devices, digital cameras, image scanning, and client/server imaging which the JPEG is not so easy to satisfy. In order to satisfy the advanced applications, the JPEG-2000 is not just optimized for coding efficiency, also includes the function of scalability and interoperability. The main difference between JPEG-2000 and conventional JPEG is that the JPEG-2000 uses the wavelet transform as a core technology while the conventional JPEG uses traditional DCT-based coding technology. The encoding process of JPEG-2000 is shown in Figure 1.5.
Image compression in resource-constrained eye tracking devices*
Published in Journal of Information and Telecommunication, 2019
Pavel Morozkin, Marc Swynghedauw, Maria Trocan
We selected JPEG2000 because its outperforms JPEG, has open source implementation, supports ROI selection feature, and allows precisely control real bpp. We use OpenJPEG (OpenJPEG, open-source JPEG, 2000 codec ) (used in this research) and Kakadu (Kakadu, closed-source JPEG, 2000 codec), because it allows to more precisely control ‘real bpp’. We also tested several non-standard wavelets by replacing standard CDF97 (Cohen-Daubechies-Feauveau CDF 9/7 wavelet GGuangjun, Lizhi, & Huowang, 2001, October, also called ‘JPEG97’) and CDF53 (also called the LeGall 5/3 wavelet Le Gall & Tabatabai, 1988, April) wavelets by other biorthogonal wavelets from Cohen-Daubechies-Feauveau family. We found that standard wavelets are still the best in most cases (except very low bitrates such as 0.15). For the eye tracking system, the quality of decompressed eye image can be lower, as proved in Morozkin, Swynghedauw, & Trocan, 2016. To enable several users to use eye tracking system with acceptable precision, size of ROI can be also increased. This leads to changing of bpp. For example, if 0.20 bpp was used to compress static ROI with selected ROI of size 120 × 120 (leads to 36 dB, Table 1), then in case of ROI of size 180 × 180, bpp has to be increased to 0.40 (leads to 37 dB, Table 1).
Land use and land cover change detection by using principal component analysis and morphological operations in remote sensing applications
Published in International Journal of Computers and Applications, 2021
Satellite images are used in the digital image processing technique to achieve enhanced spatial and spectral quality factors for obtaining accurate results. Numerous image processing techniques have been applied to satellite images. Spatial and spectral information is lost when the JPEG 2000 image compression technique is used. In a multispectral image, each pixel has a high spatial and spectral resolution. In the false color composite technique, assigning bands to the red, green, and blue channels is a difficult process. Limited channels cannot provide a large amount of information. Therefore, the limitation of false color composite technique is overcome through dimension reduction by using principal component analysis (PCA) [2].
Protocol for the morphology analysis of SBS polymer modified bitumen images obtained by using fluorescent microscopy
Published in International Journal of Pavement Engineering, 2019
Changjiang Kou, Peng Xiao, Aihong Kang, Peter Mikhailenko, Hassan Baaj, Zhengguang Wu
As lossless compression formats, BMP and TIF keep more detailed information, which can be seen from the number of particles N. However, the number of polymer particles of JPG decreases significantly due to its high compression ratio. It was evident that the JPEG 2000 format, the default storage format of the acquisition system, can preserve the details more, and so JPEG 2000 is recommended as the ideal storage format.