|
Photo Recovery
Photo recovery is the process of salvaging digital photographs from damaged, failed, corrupted, or inaccessible secondary storage media when it cannot be accessed normally. Photo recovery can be considered a subset of the overall data recovery field. Photo loss or deletion failures may be due to both hardware or software failures/errors. Recovering data after logical failure Logical Damage or the inability to view photos can occur for several reasons. The most common reasons are: # Deletion of photos # Corruption of the boot sector of media # Corruption of file system # Disk formatting # Move or copy errors Photo recovery using file carving The majority of photo recovery programs work by using a technique called file carving (data carving). There are many different file carving techniques that are used to recover photos. Most of these techniques fail in the presence of file system fragmentation. Simson Garfinkel showed that on average, 16% of JPEGs are fragmented,Simson Garf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Data Storage
Computer data storage is a technology consisting of computer components and Data storage, recording media that are used to retain digital data (computing), data. It is a core function and fundamental component of computers. The central processing unit (CPU) of a computer is what manipulates data by performing computations. In practice, almost all computers use a memory hierarchy, storage hierarchy, which puts fast but expensive and small storage options close to the CPU and slower but less expensive and larger options further away. Generally, the fast volatile technologies (which lose data when off power) are referred to as "memory", while slower persistent technologies are referred to as "storage". Even the first computer designs, Charles Babbage's Analytical Engine and Percy Ludgate's Analytical Machine, clearly distinguished between processing and memory (Babbage stored numbers as rotations of gears, while Ludgate stored numbers as displacements of rods in shuttles). Thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Recovery
In computing, data recovery is a process of retrieving deleted, inaccessible, lost, corrupted, damaged, or formatted data from secondary storage, removable media or files, when the data stored in them cannot be accessed in a usual way. The data is most often salvaged from storage media such as internal or external hard disk drives (HDDs), solid-state drives (SSDs), USB flash drives, magnetic tapes, CDs, DVDs, RAID subsystems, and other electronic devices. Recovery may be required due to physical damage to the storage devices or logical damage to the file system that prevents it from being mounted by the host operating system (OS). Logical failures occur when the hard drive devices are functional but the user or automated-OS cannot retrieve or access date stored in it. It can occur due to corrupt engineering chip, lost partitions, deleted data, firmware failure, failed formatting/re-installation. Data recovery can be a very simple or technical challenge. This is why there ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
File System
In computing, file system or filesystem (often abbreviated to fs) is a method and data structure that the operating system uses to control how data is stored and retrieved. Without a file system, data placed in a storage medium would be one large body of data with no way to tell where one piece of data stopped and the next began, or where any piece of data was located when it was time to retrieve it. By separating the data into pieces and giving each piece a name, the data are easily isolated and identified. Taking its name from the way a paper-based data management system is named, each group of data is called a "file". The structure and logic rules used to manage the groups of data and their names is called a "file system." There are many kinds of file systems, each with unique structure and logic, properties of speed, flexibility, security, size and more. Some file systems have been designed to be used for specific applications. For example, the ISO 9660 file system is designe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disk Formatting
Disk formatting is the process of preparing a data storage device such as a hard disk drive, solid-state drive, floppy disk, memory card or USB flash drive for initial use. In some cases, the formatting operation may also create one or more new file systems. The first part of the formatting process that performs basic medium preparation is often referred to as "low-level formatting". Partitioning is the common term for the second part of the process, dividing the device into several sub-devices and, in some cases, writing information to the device allowing an operating system to be booted from it. The third part of the process, usually termed "high-level formatting" most often refers to the process of generating a new file system. In some operating systems all or parts of these three processes can be combined or repeated at different levels and the term "format" is understood to mean an operation in which a new disk medium is fully prepared to store files. Some formatting utilitie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
File Carving
File carving is the process of reassembling computer files from fragments in the absence of filesystem metadata. Introduction and basic principles All filesystems contain some metadata that describes the actual file system. At a minimum, this includes the hierarchy of folders and files, with names for each. The filesystem will also record the physical locations on the storage device where each file is stored. As explained below, a file might be scattered in fragments at different physical addresses. File carving is the process of trying to recover files without this metadata. This is done by analyzing the raw data and identifying what it is (text, executable, png, mp3, etc.). This can be done in different ways, but the simplest is to look for the file signature or "magic numbers" that mark the beginning and/or end of a particular file type. For instance, every Java class file has as its first four bytes the hexadecimal value CA FE BA BE. Some files contain footers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
File System Fragmentation
In computing, file system fragmentation, sometimes called file system aging, is the tendency of a file system to lay out the contents of files non-continuously to allow in-place modification of their contents. It is a special case of data fragmentation. File system fragmentation negatively impacts seek time in spinning storage media, which is known to hinder throughput. Fragmentation can be remedied by re-organizing files and free space back into contiguous areas, a process called defragmentation. Solid-state drives do not physically seek, so their non-sequential data access is hundreds of times faster than moving drives', making fragmentation a non-issue. It is recommended to not defragment solid-state storage, because this can prematurely wear drives via unnecessary write–erase operations. Causes When a file system is first initialized on a partition, it contains only a few small internal structures and is otherwise one contiguous block of empty space. This means that the fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JPEG
JPEG ( ) is a commonly used method of lossy compression for digital images, particularly for those images produced by digital photography. The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and image quality. JPEG typically achieves 10:1 compression with little perceptible loss in image quality. Since its introduction in 1992, JPEG has been the most widely used image compression standard in the world, and the most widely used digital image format, with several billion JPEG images produced every day as of 2015. The term "JPEG" is an acronym for the Joint Photographic Experts Group, which created the standard in 1992. JPEG was largely responsible for the proliferation of digital images and digital photos across the Internet, and later social media. JPEG compression is used in a number of image file formats. JPEG/Exif is the most common image format used by digital cameras and other photographic image capture devices; along with JPEG ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Simson Garfinkel
Simson L. Garfinkel (born 1965) is Senior Data Scientist at the Department of Homeland Security (DHS). He was formerly the US Census Bureau's Senior Computer Scientist for Confidentiality and Data Access. Previously, he was a computer scientist at the National Institute of Standards and Technology (2015-2017) and, prior to that, an associate professor at the Naval Postgraduate School in Monterey, California (2006-2015). In addition to his research, Garfinkel is a journalist, an entrepreneur, and an inventor; his work is generally concerned with computer security, privacy, and information technology. Research Garfinkel's early research was in the field of optical storage. While he was an undergraduate at the MIT Media Laboratory, Garfinkel developed CDFS, the first file system for write-once optical disk systems. During the summer of 1987, he worked at Brown University's IRIS Project, where he developed a server allowing CDROMs to be shared over a network simultaneously by multipl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Truncation
In mathematics and computer science, truncation is limiting the number of digits right of the decimal point. Truncation and floor function Truncation of positive real numbers can be done using the floor function. Given a number x \in \mathbb_+ to be truncated and n \in \mathbb_0, the number of elements to be kept behind the decimal point, the truncated value of x is :\operatorname(x,n) = \frac. However, for negative numbers truncation does not round in the same direction as the floor function: truncation always rounds toward zero, the floor function rounds towards negative infinity. For a given number x \in \mathbb_-, the function ceil is used instead. :\operatorname(x,n) = \frac In some cases is written as . See Notation of floor and ceiling functions. Causes of truncation With computers, truncation can occur when a decimal number is typecast as an integer; it is truncated to zero decimal digits because integers cannot store non-integer real numbers. In algebra An a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NTFS
New Technology File System (NTFS) is a proprietary journaling file system developed by Microsoft. Starting with Windows NT 3.1, it is the default file system of the Windows NT family. It superseded File Allocation Table (FAT) as the preferred filesystem on Windows and is supported in Linux and BSD as well. NTFS reading and writing support is provided using a free and open-source kernel implementation known as NTFS3 in Linux and the NTFS-3G driver in BSD. By using the convert command, Windows can convert FAT32/16/12 into NTFS without the need to rewrite all files. NTFS uses several files typically hidden from the user to store metadata about other files stored on the drive which can help improve speed and performance when reading data. Unlike FAT and High Performance File System (HPFS), NTFS supports access control lists (ACLs), filesystem encryption, transparent compression, sparse files and file system journaling. NTFS also supports shadow copy to allow backups of a system ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Recovery
In computing, data recovery is a process of retrieving deleted, inaccessible, lost, corrupted, damaged, or formatted data from secondary storage, removable media or files, when the data stored in them cannot be accessed in a usual way. The data is most often salvaged from storage media such as internal or external hard disk drives (HDDs), solid-state drives (SSDs), USB flash drives, magnetic tapes, CDs, DVDs, RAID subsystems, and other electronic devices. Recovery may be required due to physical damage to the storage devices or logical damage to the file system that prevents it from being mounted by the host operating system (OS). Logical failures occur when the hard drive devices are functional but the user or automated-OS cannot retrieve or access date stored in it. It can occur due to corrupt engineering chip, lost partitions, deleted data, firmware failure, failed formatting/re-installation. Data recovery can be a very simple or technical challenge. This is why there ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hard Disk Software
Hard may refer to: * Hardness, resistance of physical materials to deformation or fracture * Hard water, water with high mineral content Arts and entertainment * ''Hard'' (TV series), a French TV series * Hard (band), a Hungarian hard rock supergroup * Hard (music festival), in the U.S. * ''Hard'' (EP), Goodbye Mr Mackenzie, 1993 * ''Hard'' (Brainpower album), 2008 * ''Hard'' (Gang of Four album), 1983 * ''Hard'' (Jagged Edge album), 2003 * "Hard" (song), a 2009 song by Rihanna * "Hard", a song by Royce da 5'9" from the 2016 album ''Layers'' * "Hard", a song by Why Don't We from the 2018 album ''8 Letters'' * ''Hard'', a 2017 EP from the band The Neighbourhood *"Hard", a song by Sophie from the 2015 compilation album ''Product'' Places * Hard, Austria * Hard (Zürich), Switzerland Other uses * Hard (surname) * Nickname of Masaki Sumitani ( HardGay / HardoGay ) * Hard (nautical), a beach or slope convenient for hauling out vessels * Hard (video game player), Anthony Barkho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.svg "Click for more on -> NTFS")