S3 Texture Compression (S3TC) (sometimes also called DXTn, DXTC, or BCn) is a group of related lossytexture compressionalgorithms originally developed by Iourcha et al. of S3 Graphics, Ltd.[1][2] for use in their Savage 3Dcomputer graphics accelerator. The method of compression is strikingly similar to the previously published Color Cell Compression,[3] which is in turn an adaptation of Block Truncation Coding published in the late 1970s. Unlike some image compression algorithms (e.g. JPEG), S3TC's fixed-rate data compression coupled with the single memory access (cf. Color Cell Compression and some VQ-based schemes) made it well-suited for use in compressing textures in hardware-accelerated 3D computer graphics. Its subsequent inclusion in Microsoft's DirectX 6.0 and OpenGL 1.3 (via the GL_EXT_texture_compression_s3tc extension) led to widespread adoption of the technology among hardware and software makers. While S3 Graphics is no longer a competitor in the graphics accelerator market, license fees have been levied and collected for the use of S3TC technology until October 2017, for example in game consoles and graphics cards. The wide use of S3TC has led to a de facto requirement for OpenGL drivers to support it, but the patent-encumbered status of S3TC presented a major obstacle to open source implementations,[4] while implementation approaches which tried to avoid the patented parts existed.[5]
Compress PNG with the best quality and compression. Reduce the filesize of. Upload from computer. Or drop images here. Compress images. All images will be compressed with the best quality and filesize ratio. Getting files from Drive. Getting files from Dropbox. Uploading file 0 of 0. Time left - seconds - Upload speed - MB/S. You can upload up to 25 images, 0 - 30MB per file, 0 - 50MP per image. All of your images will be removed automatically after one hour. Compression method 1. S3 Texture Compression (S3TC) (sometimes also called DXTn, DXTC, or BCn) is a group of related lossy texture compression algorithms originally developed by Iourcha et al. Of S3 Graphics, Ltd. For use in their Savage 3D computer graphics accelerator.The method of compression is strikingly similar to the previously published Color Cell Compression, which is in turn an adaptation of Block.
Patent[edit]
Some (e.g. US 5956431 A) of the multiple USPTO patents on S3 Texture Compression expired on October 2, 2017.[6] At least one continuation patent, US6,775,417, however had a 165-day extension. This continuation patent expired on March 16, 2018.
Codecs[edit]
There are five variations of the S3TC algorithm (named DXT1 through DXT5, referring to the FourCC code assigned by Microsoft to each format), each designed for specific types of image data. All convert a 4×4 block of pixels to a 64-bit or 128-bit quantity, resulting in compression ratios of 6:1 with 24-bit RGB input data or 4:1 with 32-bit RGBA input data. S3TC is a lossy compression algorithm, resulting in image quality degradation, an effect which is minimized by the ability to increase texture resolutions while maintaining the same memory requirements. Hand-drawn cartoon-like images do not compress well, nor do normal map data, both of which usually generate artifacts. ATI's 3Dc compression algorithm is a modification of DXT5 designed to overcome S3TC's shortcomings with regard to normal maps. id Software worked around the normalmap compression issues in Doom 3 by moving the red component into the alpha channel before compression and moving it back during rendering in the pixel shader.[7]
Like many modern image compression algorithms, S3TC only specifies the method used to decompress images, allowing implementers to design the compression algorithm to suit their specific needs, although the patent still covers compression algorithms. The nVidia GeForce 256 through to GeForce 4 cards also used 16-bit interpolation to render DXT1 textures, which resulted in banding when unpacking textures with color gradients. Again, this created an unfavorable impression of texture compression, not related to the fundamentals of the codec itself.
DXT1[edit]
DXT1 (also known as Block Compression 1 or BC1) is the smallest variation of S3TC, storing 16 input pixels in 64 bits of output, consisting of two 16-bit RGB 5:6:5 color values and , and a 4x4 two-bit lookup table.
If (compare these colors by interpreting them as two 16-bit unsigned numbers), then two other colors are calculated, such that for each component, and .This mode operates similarly to mode 0xC0 of the original Apple Video codec.[8]
Otherwise, if , then and is transparent black corresponding to a premultiplied alpha format.
The lookup table is then consulted to determine the color value for each pixel, with a value of 0 corresponding to and a value of 3 corresponding to .
DXT2 and DXT3[edit]
DXT2 and DXT3 (collectively also known as Block Compression 2 or BC2) converts 16 input pixels (corresponding to a 4x4 pixel block) into 128 bits of output, consisting of 64 bits of alpha channel data (4 bits for each pixel) followed by 64 bits of color data, encoded the same way as DXT1 (with the exception that the 4-color version of the DXT1 algorithm is always used instead of deciding which version to use based on the relative values of and ).
In DXT2, the color data is interpreted as being premultiplied by alpha, in DXT3 it is interpreted as not having been premultiplied by alpha. Typically DXT2/3 are well suited to images with sharp alpha transitions, between translucent and opaque areas.
DXT4 and DXT5[edit]
DXT4 and DXT5 (collectively also known as Block Compression 3 or BC3) converts 16 input pixels into 128 bits of output, consisting of 64 bits of alpha channel data (two 8-bit alpha values and a 4x4 3-bit lookup table) followed by 64 bits of color data (encoded the same way as DXT1).
If , then six other alpha values are calculated, such that , , , , , and .
Otherwise, if , four other alpha values are calculated such that , , , and with and .
The lookup table is then consulted to determine the alpha value for each pixel, with a value of 0 corresponding to and a value of 7 corresponding to . DXT4's color data is premultiplied by alpha, whereas DXT5's is not. Because DXT4/5 use an interpolated alpha scheme, they generally produce superior results for alpha (transparency) gradients than DXT2/3.
Further variants[edit]
BC4 and BC5[edit]
BC4 and BC5 (Block Compression 4 and 5) are added in Direct3D 10. They reuse the alpha channel encoding found in DXT4/5 (BC3).[9]
- BC4 stores 16 input single-channel (e.g. greyscale) pixels into 64 bits of output, encoded in the same way as BC3 alphas. The expanded palette provides higher quality.
- BC4 stores 16 input double-channel (e.g. tangent space normal map) pixels into 128 bits of output, consisting of two halves each encoded in the same way as BC3 alphas.
BC6H and BC7[edit]
BC6H (sometimes BC6) and BC7 (Block Compression 6H and 7) are added in Direct3D 11.[9]
- BC6H encodes 16 input RGB HDR (float16) pixels into 128 bits of output.
- BC7 encodes 16 input RGB8/RGBA8 pixels into 128 bits of output.
BC6H and BC7 have a much more complex algorithm with a selection of encoding modes. The quality is much better as a result.[9]
S3TC format comparison[edit]
FOURCC | DX 10/11 Name | Description | Alpha premultiplied? | Compression ratio | Texture Type |
---|---|---|---|---|---|
DXT1 | BC1 | 1-bit Alpha / Opaque | Yes | 6:1 (for 24-bit source image) | Simple non-alpha |
DXT2 | BC2 | Explicit alpha | Yes | 4:1 | Sharp alpha |
DXT3 | BC2 | Explicit alpha | No | 4:1 | Sharp alpha |
DXT4 | BC3 | Interpolated alpha | Yes | 4:1 | Gradient alpha |
DXT5 | BC3 | Interpolated alpha | No | 4:1 | Gradient alpha |
N/A | BC4 | Interpolated greyscale | N/A | 2:1 | Gradient |
N/A | BC5 | Interpolated two-channel | N/A | 2:1 | Gradient |
See also[edit]
- S2TC, patentless workaround
- Adaptive Scalable Texture Compression (ASTC)
- Ericsson Texture Compression (ETC1 & ETC2)
References[edit]
- ^US 5956431 'Fixed-rate block-based image compression with inferred pixel values'
- ^[1], Iourcha, Konstantine I.; Krishna S. Nayak & Zhou Hong, 'System and method for fixed-rate block-based image compression with inferred pixel values'
- ^'1990 IEEE Color Cell Compression Paper'. Ieeexplore.ieee.org. doi:10.1109/TENCON.1990.152671.Cite journal requires
|journal=
(help) - ^'S3TC situation on official DRI information page'. Dri.freedesktop.org. Retrieved 2012-01-25.
- ^S2TC: A Possible Workaround For The S3TC Patent Situation on phoronix
- ^Yates, Tom (2017-02-15). 'This is why I drink: a discussion of Fedora's legal state'. LWN.net. Retrieved 2017-02-16.
.. The patent on S3 texture compression expires on October 2, 2017, so Steam games might work better on Fedora after that date. ..
- ^Duffy, Robert (July 27, 2004). 'DOOM 3 Video Requirements'. Gamershell.com. Archived from the original on January 3, 2008. Retrieved 2012-01-25.
- ^Togni, Roberto, et al. 'Apple RPZA'. MultimediaWiki.
- ^ abcReed, Nathan. 'Understanding BCn Texture Compression Formats'. Nathan Reed’s coding blog.
External links[edit]
- squish, an MIT-licensed S3TC compressor. The site also contains an article giving an introduction to compression algorithms.
- The Truth about S3TC Note: This article used an early S3TC compression engine, not nVidia's or ATI's updated codecs.
(Wayback Machine copy)
- Texture compression survey
Retrieved from 'https://en.wikipedia.org/w/index.php?title=S3_Texture_Compression&oldid=976125355'
What are post-surgery compression garments?
LIPOELASTIC® post-surgery compression garments are designed for postoperative treatment following plastic-aesthetic procedures such as liposuction, mammoplasty, augmentation or reconstruction of breasts, abdominoplasty, facelifting, necklifting etc.
What are post-surgery compression garments?Why you should use post-surgery compression garmentsWhat does compression therapy ensure?BenefitsCERTIFICATION OF MATERIALSCertificates2 STEPS FOR THE PERFECT RESULT OF LIPOSUCTIONTypes of materialWhat doctors say2 STEPS FOR PERFECT AUGMENTATION RESULTFAQ
Why you should use post-surgery compression garments
Compression garment is an inseparable part of postoperative care . In some cases, not wearing the right post-surgery compression garment can lead to critical consequences. Among these can be a significantly different result of the procedure than that which the patient was counting on.
Another reason in favor of using post-surgery compression garments is that it speeds up the healing process and therefore the client can make a quick return to everyday activities.
2-4 weeks after procedure
100% of patients who use post-surgery garments return back to everyday activities faster than those who do not use the under garments after the surgery.
Defined ductility and elasticity
Does not contain latex
Compression garments pleasant to the touch
Flat seams
Custom made orders
CERTIFICATION OF MATERIALS
Top-quality materials, custom-made by producers in EU, are used for LIPOELASTIC® garments. All materials are regularly tested at the Textile Testing Institute TZÚ in Brno - Czech Republic.
The key criteria, carefully monitored, are the parameters of longitudinal and cross-section compression of textiles. These tests are carried out in accordance with the methods of the company DuPont, a world-renowned producer of elastic fibers under the Lycra trademark.
These regular tests enable us to guarantee our partners the required compression of garments ranging from 20-30 mmHg. The individual garment types are put on torsos simulating particular body parts and continuously tested using the measuring device MST MK IV from the Swiss producer Swisslastic AG.
These regular tests enable us to guarantee our partners the required compression of garments ranging from 17-22 mmHg. The individual garment types are put on torsos simulating particular body parts and continuously tested using the measuring device MST MK IV from the Swiss producer Swisslastic AG.
Material certificates
Permeability of moisture evaporation
Top-most resistance according to CSN EN 31092 standard is between 2-3 m2Pa/W. LIPOELASTIC® material meets the ideal value 2,57 m2Pa/W
Conveyance and management of perspiration
The value of perspiration conveyance between 800 – 900 g/m2H is first-rate. The results of LIPOELASTIC® materials reach the value 815 g/m2H.
Moisture control
Compress 1 0 3 – Image Compression Garments Garment
Tests results showed that the moisture control with LIPOELASTIC® material is 85%. This result provides the patient with the feeling of dryness during wear.
1 : 0,85
Certificates of quality assurance
OEKO-TEX
This guarantees the absence of harmful substances in our garments, which are tested annually by the Trial Institute Hohenstein in Germany. This certificate is a guarantee of the quality and safety of our products. All garments are Latex-free.
ISO 13485:2016
LIPOELASTIC products are manufactured in a production facility which meets quality management requirements for ISO 13485.
CE – Declaration of conformity
LIPOELASTIC® products meet the requirements of the Medical Device Directive 93/42/EEC. The LIPOELASTIC® products are authorized to use the CE mark.
2 STEPS FOR THE PERFECT RESULT
OF LIPOSUCTION
Benefits
• Minimises swelling and bruises • Improves blood circulation • Eliminates risk of infection • Guaranted elasticity and adjustment to your form throughout the entire stage of compression therapy
*Illustrative photo
The final outcome may be significantly influenced by, among other things, improper postoperative care. To help patients achieve the best result and ease post-surgical developments, the company LIPOELASTIC has developed a two-phase program of compression therapy. They are the collections Classic (compression garments designed for the immediate post-operative phase) and Unique (for use during follow-up treatment.)
1st STEP
- Use immediately after operation
- Recommended wear for 1 - 2 weeks
- Innovation of existing garments collections
- Enriched with nanoparticles of silver: slow the spread of microbes,
- Speed up the healing process without odor
The existing collections of compression garments have now been innovated with the collection Classic and enriched with nano-particles of silver. The anti-bacterial properties eliminate the growth of bacteria, the healing process is sped up and there is no unpleasant odor. So during the first two weeks the patient will feel as if they are wrapped in cotton wool (even though, in fact, the materials LIPOELASTIC uses for its garments are far more sophisticated and guarantee constant ductility).
2nd STEP
- Use during the second step of post-operative therapy
- Recommended wear for 3 - 6 weeks following the first step
- Adjustable compression via special three-row of hooks fastening, enables adjustment of bandage size after swelling subsides
- Perforated 3D material maintains microclimate
- High-comfort for long-term wear and putting on
Unique compression garments come in the next phase of therapy. This phase is less painful. Special fastening allows the patient to adjust the level of compression to his or her comfort. Perforated 3D material maintains a constant microclimate and makes putting the garments on and wearing them much more comfortable. You will certainly appreciate this because, in some cases, you will have to wear these garments for up to six weeks.
1st STEP
- Use immediately after operation
- Recommended wear for 1 - 2 weeks
- speed up the healing process without odor
The existing collections of compression garments with the collection Classic are recommended during the first two weeks. The patient will feel as if they are wrapped in cotton wool (even though, in fact, the materials LIPOELASTIC uses for its garments are far more sophisticated and guarantee constant ductility).
2nd STEP
- Use during the second step of post-operative therapy
- Recommended wear for 3 - 6 weeks following the first step
- Adjustable compression via special three-row of hooks fastening, enables adjustment of bandage size after swelling subsides
- Perforated 3D material maintains microclimate
- High-comfort for long-term wear and putting on
Unique Compression garments come in the next phase of therapy. This phase is less painful. Special fastening allows the patient to adjust the level of compression to his or her comfort. Perforated 3D material maintains a constant microclimate and makes putting the garments on and wearing them much more comfortable. You will certainly appreciate this because, in some cases, you will have to wear these garments for up to six weeks.
LIPOELASTIC® garments meet the highest criteria for compression therapy.
They significantly speed up the healing process and thus enable the user to make a smoother return to everyday activities.
Their carefully crafted manufacture, design and easy-to-use characteristics are the icing on the cake.
TYPES OF MATERIAL
CLASSIC material
A long-proven and now new and improved collection.
Design options:
Comfort
Zippers are underlain with a row of hooks and eyes closure for easy fastening in the days immediately following the procedure.
Variant
3-positional hook and eye closure, enables adjustment of bandage size after swelling subsides. Possibility to adjust compression enhances healing.
RIB material
A new material made especially for LIPOELASTIC. Its compression ensures tightness around the body without the need for double underlay. The material is very comfortable for everyday wear and very pleasant to the touch.
The material can be used for both the first and second phase of post-operative care.
The material can be used for both the first and second phase of post-operative care.
Design options:
Comfort
Zippers are underlain with a row of hooks and eyes closure for easy fastening in the days immediately following the procedure.
Variant
3-positional hook and eye closure, enables adjustment of bandage size after swelling subsides. Possibility to adjust compression enhances healing.
UNIQUE material
Easy to put on without assistance.
MICRO CLIMA
Perforated 3D material touches the skin only in some points. It massages skin during movement, thus increasing blood circulation. Special 3D perforation absorbs and takes away moisture, maintaining microclimate.
Variant
3-positional hook and eye closure, enables adjustment of bandage size after swelling subsides. Possibility to adjust compression enhances healing.
What do doctors say about post-operativ compression garments?
2 STEPS FOR THE PERFECT RESULT
OF AUGMENTATION
Benefits
Compression Garments For Men
• Minimises swelling and bruises • Improves blood circulation • Eliminates risk of infection • Forms the contours and stabilises the implants
PI SPECIAL
- WEAR IMMEDIATELY AFTER AUGMENTATION
- RECOMMENDED USE: 3 WEEKS
Invaluable aid for use during the first stage of post-surgery care to promote ideal breast shaping. The main advantage of this bra are the cups which are seamless, double-layered and heat-molded from elastic cotton material, which is very comfortable even during long-term wear. This design eliminates unwanted pressure or skin irritation while at the same time enabling easy manipulation. Specially reinforced cups ensure an even rate of compression and optimal breast support.
For pleasant feeling during wear and easy handling
- prevents unwanted pressure and skin irritation
- controlled compression
- seamless design relieves the lymphatic system
- easy to tolerate, soft material
- durability and resistance
PI UNIQUE
- WEAR AS A FOLLOW-UP CARE AFTER THE FIRST PHASE
- RECOMMENDED USE: 5 WEEKS
PI UNIQUE is latest leading product in the area of compression bras from LIPOELASTIC. It is designed to be worn mainly by very demanding women who do not wish to compromise themselves even in the period of their convalescence. The shaped cups are designed for the second stage of post-surgery care. However, their design reveals much about their further potential use.
For the long-lasting fresh feeling of your skin
- The breathable material enables circulation of air and prevents moisture from cumulating
- It maintains a constant body temperature
- It protects the body against cold
FAQ – the frequently asked questions
Why should I choose compression garments from LIPOELASTIC?
LIPOELASTIC has been successfully producing post-surgery compression garments since 2002. Our products are made from certified materials and meet all the requirements of compression therapy. We continuously develop new products based on feedback from physicians and patients. We would not be counted amongst the absolute topmost producers in this field world-wide without satisfied customers.
Why do I need compression garments after the surgery?
Compression therapy is one of the oldest postoperative methods in general; and most physicians use its benefits even now. Compression garments minimize the occurrence of swelling, bruises and scars. Also, their positive effect on blood circulation has been proven. Moreover, compression reduces the risk of infection and pain. Compression garments are important to shape contours and stabilize the implants after plastic surgery.
Why should I buy 2 pieces of compression garments?
Compression garments in general speed up the healing process. If you do not use any garments, the convalescence may not only take much longer, but the result of the surgery may not be as you had expected it. In every phase of the convalescence process the body reacts and looks differently. That is the reason why LIPOELASTIC has developed this 2-step program for maximum healing efficiency and the best result of the surgery. We guarantee a speedy return to everyday activities without side effects (smooth and even skin after liposuction, no breast asymmetry etc.).
How can I choose the right size?
Your physician should assist you in choosing the right garments. In some cases he or she can refer you directly to the company LIPOELASTIC. It is all right, we will be happy to advise you. In order to provide you with a qualified answer, we will need to know some information about the surgery which you have undergone or which you are planning to undergo. We will be mostly interested in which part of your body will be treated and the size change.
Where can I buy LIPOELASTIC compression postoperative garments?
Tagr 5 1 0 mac. Please, contact us on [email protected] and we will inform you where you can buy our products in your country.