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Compression d'images

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Image compression is a critical technique in digital technologie[3], enabling efficient storage and transmission of images. This process involves reducing the size of an image file without significantly affecting its quality. Various techniques are used, including lossy and lossless methods, transform coding, color quantization, and more. The history of image compression dates back to the 1940s, with significant developments such as the introduction of the Discrete Cosine Transform in 1973 and the creation of JPEG[4] in 1992. There are also progressive compression techniques that improve user experience[2] by allowing images to load in stages. The field also encompasses issues such as JPEG copy protection, which seeks to prevent unauthorized use or alteration of images. Furthermore, there are various standards in image and other types of data compression, such as DEFLATE and JPEG2000 for images, H.261, H.262, H.263 for video, and G.711, G.726, G.729 for audio, which play a crucial role in ensuring interopérabilité[1].

Définitions des termes
1. interopérabilité. L'interopérabilité, dans le domaine des technologies et des systèmes, est la capacité de différents systèmes ou produits à fonctionner ensemble et à échanger des informations de manière transparente. Elle comprend différents types d'interopérabilité, tels que l'interopérabilité syntaxique, qui garantit des formats de données et des protocoles communs, et l'interopérabilité sémantique, qui permet une interprétation significative des données. L'interopérabilité interdomaines facilite l'échange de données entre plusieurs entités. Les normes d'interopérabilité facilitent la création de produits qui peuvent coopérer sans effort. L'interopérabilité a posteriori est importante dans les paysages concurrentiels où les produits dominants fixent les normes du marché. Les défis comprennent l'encombrement des données et l'absence de normes ouvertes, mais les solutions résident dans l'amélioration de l'interopérabilité de l'infrastructure et la promotion de normes ouvertes. L'interopérabilité spécifique à un secteur, comme dans les forces de l'OTAN ou les services d'administration en ligne, est cruciale pour une collaboration efficace et une prestation de services efficiente.
2. user experience. User Experience (UX) is a broad term that encompasses every aspect of an end-user's interaction with a company, its services, or its products. This includes users' perceptions and responses, both emotional and cognitive, during and after the use of a system, product, or service. User Experience also involves users' beliefs, preferences, and behaviors. While usability, a component of UX, focuses on the practical aspects of a system, UX incorporates a holistic view of system use. User experience is a vital factor in increasing brand loyalty and customer base growth. Its history dates back to the Machine Age, with notable contributions from figures like Frederick Winslow Taylor, Henry Ford, and Donald Norman. Today, technology advancements continue to shape and expand the field.Developer Experience (DX) is the analog of UX for software developers. It represents the experience developers have with the tools, processes, and software they use in their work. A high-quality DX can significantly impact the overall user experience, thus contributing to the success of the product. The importance of DX is increasingly recognized in the field of software services, where ease of use can serve as a key market differentiator. This concept has been explored by various authors and researchers, and it's also emphasized in international standards like ISO 9241-210, which advocates for human-centered design.

Compression d'images is a type of data compression applied to images numériques, to reduce their cost for storage ou transmission. Algorithms may take advantage of visual perception et le statistical properties of image data to provide superior results compared with generic data compression methods which are used for other digital data.

Comparison of JPEG images saved by Adobe Photoshop at different quality levels and with or without "save for web"
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