JPEG-1 History - When and How the Royalty-Free JPEG Patent Policy Got Lost
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Exploring the .BMP File Format
Exploring the .BMP File Format Don Lancaster Synergetics, Box 809, Thatcher, AZ 85552 copyright c2003 as GuruGram #14 http://www.tinaja.com [email protected] (928) 428-4073 The .BMP image standard is used by Windows and elsewhere to represent graphics images in any of several different display and compression options. The .BMP advantages are that each pixel is usually independently available for any alteration or modification. And that repeated use does not normally degrade the image. Because lossy compression is not used. Its main disadvantage is that file sizes are usually horrendous compared to JPEG, fractal, GIF, or other lossy compression schemes. A comparison of popular image standards can be found here. I’ve long been using the .BMP format for my eBay and my other phototography, scanning, and post processing. I firmly believe that… All photography, scanning, and all image post-processing should always be done using .BMP or a similar non-lossy format. Only after all post-processing is complete should JPEG or another compressed distribution format be chosen. Some current examples of my .BMP work now do include the IMAGIMAG.PDF post-processing tutorial, the Bitmap Typewriterthat generates fully anti-aliased small fonts, the Aerial Photo Combiner, and similar utilities and tutorials found on our Fonts & Images, PostScript, and on our Acrobat library pages. A few projects of current interest involving .BMP files include true view camera swings and tilts for a digital camera, distortion correction, dodging & burning, preventing white punchthrough on knockouts, and emphasis vignetting. Mainly applied to uncompressed RGBX 24-bit color .BMP files. -
ITU-T Rec. T.800 (08/2002) Information Technology
INTERNATIONAL TELECOMMUNICATION UNION ITU-T T.800 TELECOMMUNICATION (08/2002) STANDARDIZATION SECTOR OF ITU SERIES T: TERMINALS FOR TELEMATIC SERVICES Information technology – JPEG 2000 image coding system: Core coding system ITU-T Recommendation T.800 INTERNATIONAL STANDARD ISO/IEC 15444-1 ITU-T RECOMMENDATION T.800 Information technology – JPEG 2000 image coding system: Core coding system Summary This Recommendation | International Standard defines a set of lossless (bit-preserving) and lossy compression methods for coding bi-level, continuous-tone grey-scale, palletized color, or continuous-tone colour digital still images. This Recommendation | International Standard: – specifies decoding processes for converting compressed image data to reconstructed image data; – specifies a codestream syntax containing information for interpreting the compressed image data; – specifies a file format; – provides guidance on encoding processes for converting source image data to compressed image data; – provides guidance on how to implement these processes in practice. Source ITU-T Recommendation T.800 was prepared by ITU-T Study Group 16 (2001-2004) and approved on 29 August 2002. An identical text is also published as ISO/IEC 15444-1. ITU-T Rec. T.800 (08/2002 E) i FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. -
Free Lossless Image Format
FREE LOSSLESS IMAGE FORMAT Jon Sneyers and Pieter Wuille [email protected] [email protected] Cloudinary Blockstream ICIP 2016, September 26th DON’T WE HAVE ENOUGH IMAGE FORMATS ALREADY? • JPEG, PNG, GIF, WebP, JPEG 2000, JPEG XR, JPEG-LS, JBIG(2), APNG, MNG, BPG, TIFF, BMP, TGA, PCX, PBM/PGM/PPM, PAM, … • Obligatory XKCD comic: YES, BUT… • There are many kinds of images: photographs, medical images, diagrams, plots, maps, line art, paintings, comics, logos, game graphics, textures, rendered scenes, scanned documents, screenshots, … EVERYTHING SUCKS AT SOMETHING • None of the existing formats works well on all kinds of images. • JPEG / JP2 / JXR is great for photographs, but… • PNG / GIF is great for line art, but… • WebP: basically two totally different formats • Lossy WebP: somewhat better than (moz)JPEG • Lossless WebP: somewhat better than PNG • They are both .webp, but you still have to pick the format GOAL: ONE FORMAT THAT COMPRESSES ALL IMAGES WELL EXPERIMENTAL RESULTS Corpus Lossless formats JPEG* (bit depth) FLIF FLIF* WebP BPG PNG PNG* JP2* JXR JLS 100% 90% interlaced PNGs, we used OptiPNG [21]. For BPG we used [4] 8 1.002 1.000 1.234 1.318 1.480 2.108 1.253 1.676 1.242 1.054 0.302 the options -m 9 -e jctvc; for WebP we used -m 6 -q [4] 16 1.017 1.000 / / 1.414 1.502 1.012 2.011 1.111 / / 100. For the other formats we used default lossless options. [5] 8 1.032 1.000 1.099 1.163 1.429 1.664 1.097 1.248 1.500 1.017 0.302� [6] 8 1.003 1.000 1.040 1.081 1.282 1.441 1.074 1.168 1.225 0.980 0.263 Figure 4 shows the results; see [22] for more details. -
What Resolution Should Your Images Be?
What Resolution Should Your Images Be? The best way to determine the optimum resolution is to think about the final use of your images. For publication you’ll need the highest resolution, for desktop printing lower, and for web or classroom use, lower still. The following table is a general guide; detailed explanations follow. Use Pixel Size Resolution Preferred Approx. File File Format Size Projected in class About 1024 pixels wide 102 DPI JPEG 300–600 K for a horizontal image; or 768 pixels high for a vertical one Web site About 400–600 pixels 72 DPI JPEG 20–200 K wide for a large image; 100–200 for a thumbnail image Printed in a book Multiply intended print 300 DPI EPS or TIFF 6–10 MB or art magazine size by resolution; e.g. an image to be printed as 6” W x 4” H would be 1800 x 1200 pixels. Printed on a Multiply intended print 200 DPI EPS or TIFF 2-3 MB laserwriter size by resolution; e.g. an image to be printed as 6” W x 4” H would be 1200 x 800 pixels. Digital Camera Photos Digital cameras have a range of preset resolutions which vary from camera to camera. Designation Resolution Max. Image size at Printable size on 300 DPI a color printer 4 Megapixels 2272 x 1704 pixels 7.5” x 5.7” 12” x 9” 3 Megapixels 2048 x 1536 pixels 6.8” x 5” 11” x 8.5” 2 Megapixels 1600 x 1200 pixels 5.3” x 4” 6” x 4” 1 Megapixel 1024 x 768 pixels 3.5” x 2.5” 5” x 3 If you can, you generally want to shoot larger than you need, then sharpen the image and reduce its size in Photoshop. -
JPEG File Interchange Format Version 1.02
JPEG File Interchange Format Version 1.02 September 1, 1992 Eric Hamilton C-Cube Microsystems 1778 McCarthy Blvd. Milpitas, CA 95035 +1 408 944-6300 Fax: +1 408 944-6314 E-mail: [email protected] JPEG File Interchange Format Version 1.02 Why a File Interchange Format JPEG File Interchange Format is a minimal file format which enables JPEG bitstreams to be exchanged between a wide variety of platforms and applications. This minimal format does not include any of the advanced features found in the TIFF JPEG specification or any application specific file format. Nor should it, for the only purpose of this simplified format is to allow the exchange of JPEG compressed images. JPEG File Interchange Format features • Uses JPEG compression • Uses JPEG interchange format compressed image representation • PC or Mac or Unix workstation compatible • Standard color space: one or three components. For three components, YCbCr (CCIR 601-256 levels) • APP0 marker used to specify Units, X pixel density, Y pixel density, thumbnail • APP0 marker also used to specify JFIF extensions • APP0 marker also used to specify application-specific information JPEG Compression Although any JPEG process is supported by the syntax of the JPEG File Interchange Format (JFIF) it is strongly recommended that the JPEG baseline process be used for the purposes of file interchange. This ensures maximum compatibility with all applications supporting JPEG. JFIF conforms to the JPEG Draft International Standard (ISO DIS 10918-1). The JPEG File Interchange Format is entirely compatible with the standard JPEG interchange format; the only additional requirement is the mandatory presence of the APP0 marker right after the SOI marker. -
Quadtree Based JBIG Compression
Quadtree Based JBIG Compression B. Fowler R. Arps A. El Gamal D. Yang ISL, Stanford University, Stanford, CA 94305-4055 ffowler,arps,abbas,[email protected] Abstract A JBIG compliant, quadtree based, lossless image compression algorithm is describ ed. In terms of the numb er of arithmetic co ding op erations required to co de an image, this algorithm is signi cantly faster than previous JBIG algorithm variations. Based on this criterion, our algorithm achieves an average sp eed increase of more than 9 times with only a 5 decrease in compression when tested on the eight CCITT bi-level test images and compared against the basic non-progressive JBIG algorithm. The fastest JBIG variation that we know of, using \PRES" resolution reduction and progressive buildup, achieved an average sp eed increase of less than 6 times with a 7 decrease in compression, under the same conditions. 1 Intro duction In facsimile applications it is desirable to integrate a bilevel image sensor with loss- less compression on the same chip. Suchintegration would lower p ower consumption, improve reliability, and reduce system cost. To reap these b ene ts, however, the se- lection of the compression algorithm must takeinto consideration the implementation tradeo s intro duced byintegration. On the one hand, integration enhances the p os- sibility of parallelism which, if prop erly exploited, can sp eed up compression. On the other hand, the compression circuitry cannot b e to o complex b ecause of limitations on the available chip area. Moreover, most of the chip area on a bilevel image sensor must b e o ccupied by photo detectors, leaving only the edges for digital logic. -
JPEG-Resistant Adversarial Images
JPEG-resistant Adversarial Images Richard Shin Dawn Song Computer Science Division Computer Science Division University of California, Berkeley University of California, Berkeley [email protected] [email protected] Abstract Several papers have explored the use of JPEG compression as a defense against adversarial images [3, 2, 5]. In this work, we show that we can generate adversarial images which survive JPEG compression, by including a differentiable approxima- tion to JPEG in the target model. By ensembling multiple target models employing varying levels of compression, we generate adversarial images with up to 691× greater success rate than the baseline method on a model using JPEG as defense. 1 Introduction Image classification models has been a highly-studied domain for adversarial examples. While adversarial images generated against these models are nevertheless very close to the original image according to L1 or L2 norm, unnatural high-frequency components or random-looking dot patterns are sometimes noticeable. As such, some proposed defenses to adversarial examples involve an initial input transformation step which attempts to remove such unnatural-looking additions. In particular, several papers [3, 2, 5] have proposed and evaluated JPEG compression as a potential method for preventing adversarial images. To summarize, they compress and then decompress an image using JPEG before providing it to the image classification model. Since JPEG is a lossy image compression method designed to preferentially preserve details important to the human visual system, the hope is that JPEG compression will keep the aspects of the image important for classification, but discard any adversarial perturbations. The method is appealingly simple and, according to the previous work, can reduce the attack success rate of adversarial examples. -
Using Graphics on the Web Keep Graphics Small Most Users Have Little Patience for Slow Loading Pages, and Will Rapidly Abandon a Slow Site
Using graphics on the web Keep graphics small Most users have little patience for slow loading pages, and will rapidly abandon a slow site. Remember that many of your audience will be using a dial up modem, and try to keep graphics file sizes under 40K. Be willing to sacrifice some image quality. Provide thumbnails for large graphics If you feel your site absolutely requires large graphics, to illustrate an experimental set-up for example, provide an in-line reduced thumbnail of the graphic on your main page, which will link to the larger graphic and a separate page. This way the user has a choice and can decide if she or he wants to view it then, at another time or at all. It's also a kindness to indicate the file size, so the user can estimate how long the display will take to load. Use the same motifs throughout your site Recycle graphics (icons, navigation bars), as they are cached locally once downloaded. Standardizing on a set of graphic arrows, bullets, logos etc. also provides your site with a characteristic "look and feel" that your audience can identify with. Provide alternative text for non-graphics browsers Use the [alt="" ] command to provide a text description for those with text-only browsers or those who may have graphics loading disabled on their browsers. This also follows guidelines for Americans with Disabilities Act (ADA) Compliance. Use the appropriate file format Graphics Interchange format - GIF - was originally developed for the rapid transfer of images. GIF compression works by encoding the identical repeating elements within any given graphic, storing the code in an attached table and using the data to display the image when called upon by the web browser. -
Understanding Image Formats and When to Use Them
Understanding Image Formats And When to Use Them Are you familiar with the extensions after your images? There are so many image formats that it’s so easy to get confused! File extensions like .jpeg, .bmp, .gif, and more can be seen after an image’s file name. Most of us disregard it, thinking there is no significance regarding these image formats. These are all different and not cross‐ compatible. These image formats have their own pros and cons. They were created for specific, yet different purposes. What’s the difference, and when is each format appropriate to use? Every graphic you see online is an image file. Most everything you see printed on paper, plastic or a t‐shirt came from an image file. These files come in a variety of formats, and each is optimized for a specific use. Using the right type for the right job means your design will come out picture perfect and just how you intended. The wrong format could mean a bad print or a poor web image, a giant download or a missing graphic in an email Most image files fit into one of two general categories—raster files and vector files—and each category has its own specific uses. This breakdown isn’t perfect. For example, certain formats can actually contain elements of both types. But this is a good place to start when thinking about which format to use for your projects. Raster Images Raster images are made up of a set grid of dots called pixels where each pixel is assigned a color. -
JPEG and JPEG 2000
JPEG and JPEG 2000 Past, present, and future Richard Clark Elysium Ltd, Crowborough, UK [email protected] Planned presentation Brief introduction JPEG – 25 years of standards… Shortfalls and issues Why JPEG 2000? JPEG 2000 – imaging architecture JPEG 2000 – what it is (should be!) Current activities New and continuing work… +44 1892 667411 - [email protected] Introductions Richard Clark – Working in technical standardisation since early 70’s – Fax, email, character coding (8859-1 is basis of HTML), image coding, multimedia – Elysium, set up in ’91 as SME innovator on the Web – Currently looks after JPEG web site, historical archive, some PR, some standards as editor (extensions to JPEG, JPEG-LS, MIME type RFC and software reference for JPEG 2000), HD Photo in JPEG, and the UK MPEG and JPEG committees – Plus some work that is actually funded……. +44 1892 667411 - [email protected] Elysium in Europe ACTS project – SPEAR – advanced JPEG tools ESPRIT project – Eurostill – consensus building on JPEG 2000 IST – Migrator 2000 – tool migration and feature exploitation of JPEG 2000 – 2KAN – JPEG 2000 advanced networking Plus some other involvement through CEN in cultural heritage and medical imaging, Interreg and others +44 1892 667411 - [email protected] 25 years of standards JPEG – Joint Photographic Experts Group, joint venture between ISO and CCITT (now ITU-T) Evolved from photo-videotex, character coding First meeting March 83 – JPEG proper started in July 86. 42nd meeting in Lausanne, next week… Attendance through national -
MPEG Compression Is Based on Processing 8 X 8 Pixel Blocks
MPEG-1 & MPEG-2 Compression 6th of March, 2002, Mauri Kangas Contents: • MPEG Background • MPEG-1 Standard (shortly) • MPEG-2 Standard (shortly) • MPEG-1 and MPEG-2 Differencies • MPEG Encoding and Decoding • Colour sub-sampling • Motion Compensation • Slices, macroblocks, blocks, etc. • DCT • MPEG-2 bit stream syntax • MPEG-2 • Supported Features • Levels • Profiles • DVB Systems 1 © Mauri Kangas 2002 MPEG-1,2.PPT/ 24.02.2002 / Mauri Kangas MPEG Background • MPEG = Motion Picture Expert Group • ISO/IEC JTC1/SC29 • WG11 Motion Picture Experts Group (MPEG) • WG10 Joint Photographic Experts Group (JPEG) • WG7 Computer Graphics Experts Group (CGEG) • WG9 Joint Bi-level Image coding experts Group (JBIG) • WG12 Multimedia and Hypermedia information coding Experts Group (MHEG) • MPEG-1,2 Standardization 1988- • Requirement • System • Video • Audio • Implementation • Testing • Latest MPEG Standardization: MPEG-4, MPEG-7, MPEG-21 2 © Mauri Kangas 2002 MPEG-1,2.PPT/ 24.02.2002 / Mauri Kangas MPEG-1 Standard ISO/IEC 11172-2 (1991) "Coding of moving pictures and associated audio for digital storage media" Video • optimized for bitrates around 1.5 Mbit/s • originally optimized for SIF picture format, but not limited to it: • 352x240 pixels a 30 frames/sec [ NTSC based ] • 352x288 pixels at 25 frames/sec [ PAL based ] • progressive frames only - no direct provision for interlaced video applications, such as broadcast television Audio • joint stereo audio coding at 192 kbit/s (layer 2) System • mainly designed for error-free digital storage media • -
CISC 3635 [36] Multimedia Coding and Compression
Brooklyn College Department of Computer and Information Sciences CISC 3635 [36] Multimedia Coding and Compression 3 hours lecture; 3 credits Media types and their representation. Multimedia coding and compression. Lossless data compression. Lossy data compression. Compression standards: text, audio, image, fax, and video. Course Outline: 1. Media Types and Their Representations (Week 1-2) a. Text b. Analog and Digital Audio c. Digitization of Sound d. Musical Instrument Digital Interface (MIDI) e. Audio Coding: Pulse Code Modulation (PCM) f. Graphics and Images Data Representation g. Image File Formats: GIF, JPEG, PNG, TIFF, BMP, etc. h. Color Science and Models i. Fax j. Video Concepts k. Video Signals: Component, Composite, S-Video l. Analog and Digital Video: NTSC, PAL, SECAM, HDTV 2. Lossless Compression Algorithms (Week 3-4) a. Basics of Information Theory b. Run-Length Coding c. Variable Length Coding: Huffman Coding d. Basic Fax Compression e. Dictionary Based Coding: LZW Compression f. Arithmetic Coding g. Lossless Image Compression 3. Lossy Compression Algorithms (Week 5-6) a. Distortion Measures b. Quantization c. Transform Coding d. Wavelet Based Coding e. Embedded Zerotree of Wavelet (EZW) Coefficients 4. Basic Audio Compression (Week 7-8) a. Differential Coders: DPCM, ADPCM, DM b. Vocoders c. Linear Predictive Coding (LPC) d. CELP e. Audio Standards: G.711, G.726, G.723, G.728. G.729, etc. 5. Image Compression Standards (Week 9) a. The JPEG Standard b. JPEG 2000 c. JPEG-LS d. Bilevel Image Compression Standards: JBIG, JBIG2 6. Basic Video Compression (Week 10) a. Video Compression Based on Motion Compensation b. Search for Motion Vectors c.