Bolovo
18-05-2004, 22:41:24
Ontem o site Computerbase.de acusou a ATI de usar trapaças com filtros. A ATi não usa filtro trilinear+AF, mas sim "brilinear"( mistura de bilinear e trilinear e algumas mudança no algoritimo) e o desempenho é muito melhor assim, mas perde em termos de qualidade de imagem. A ATI foi acusada de fazer coisas que a Nvidia já fizera. Hoje a ATI responde sobre as acusações:
Resposta da ATI em Ingles
There has been a lot of discussion about our trilinear filtering algorithms recently.
The objective of trilinear filtering is to make transitions between mipmap levels as near to invisible as possible. As long as this is achieved, there is no "right" or "wrong" way to implement the filtering.
We have added intelligence to our filtering algorithm to increase performance without affecting image quality. As some people have discovered, it is possible to show differences between our filtering implementations for the RADEON 9800XT and RADEON X800. However, these differences can only be seen by subtracting before and after screenshots and amplifying the result. No-one has claimed that the differences make one implementation "better" than another.
Our algorithm for image analysis-based texture filtering techniques is patent-pending. It works by determining how different one mipmap level is from the next and then applying the appropriate level of filtering. It only applies this optimization to the typical case - specifically, where the mipmaps are generated using box filtering. Atypical situations, where each mipmap could differ significantly from the previous level, receive no optimizations. This includes extreme cases such as colored mipmap levels, which is why tests based on color mipmap levels show different results. Just to be explicit: there is no application detection going on; this just illustrates the sophistication of the algorithm.
We encourage users to experiment with moving the texture preference slider from "Quality" towards "Performance" - you will see huge performance gains with no effect on image quality until the very end, and even then, the effect is hardly noticeable. We are confident that we give gamers the best image quality at every performance level.
Microsoft does set some standards for texture filtering and the company's WHQL process includes extensive image quality tests for trilinear filtering and mipmapping. CATALYST passes all these tests - and without application detection, which could be used if you wanted to get a lower-quality algorithm go undetected through the tests.
Finally, ATI takes image quality extremely seriously and we are confident that we set the bar for the whole industry. We don't undertake changes to our filtering algorithms lightly, and perform considerable on-line and off-line image analysis before implementing changes. This algorithm has been in public use for over a year in our RADEON 9600 series products, and we have not received any adverse comments on image quality in that time. If anyone does find any quality degradation as a result of this algorithm, they are invited to report it to ATI. If there is a problem, we will fix it.
Resposta da ATI, toscamente traduzida
Pra quem não entende inglês, resumidamente:
Eles disseram que é uma tecnologia diferente, que está sendo patenteada, e que as diferenças são percebidas apenas "comparando screenshots apliadas com e sem o algoritmo", e que esse tipo de comparação não é válida para apontar que uma implementação é melhor do que outra.
O algoritmo funciona determinando o quanto diferente um "mipmap" é do próximo, e então aplicando o somente o filtro apropriado (necessário). Eles frisam que em situações atípicas (em que os "mipmaps" são muito diferentes, não é aplicada qualquer otimização.
Frisam também que o driver não detecta a aplicação que está rodando em momento algum, ou seja, o procedimento é o mesmo pra qualquer jogo ou benchmark, o que segundo eles dá uma idéia da sofisticação do algoritmo.
Se alguém perceber qualquer degradação na qualidade de imagem como resultado desse algoritmo, pode reportar isso à ATI. Se há algum problema, corrigiremos.
Driveheaven (http://www.driverheaven.net/#article_13615)
Fonte: ForumPcs
hehehe o q isso ATI!!! Agora ate vc!!! :sm01: :p
A[B]'s
Resposta da ATI em Ingles
There has been a lot of discussion about our trilinear filtering algorithms recently.
The objective of trilinear filtering is to make transitions between mipmap levels as near to invisible as possible. As long as this is achieved, there is no "right" or "wrong" way to implement the filtering.
We have added intelligence to our filtering algorithm to increase performance without affecting image quality. As some people have discovered, it is possible to show differences between our filtering implementations for the RADEON 9800XT and RADEON X800. However, these differences can only be seen by subtracting before and after screenshots and amplifying the result. No-one has claimed that the differences make one implementation "better" than another.
Our algorithm for image analysis-based texture filtering techniques is patent-pending. It works by determining how different one mipmap level is from the next and then applying the appropriate level of filtering. It only applies this optimization to the typical case - specifically, where the mipmaps are generated using box filtering. Atypical situations, where each mipmap could differ significantly from the previous level, receive no optimizations. This includes extreme cases such as colored mipmap levels, which is why tests based on color mipmap levels show different results. Just to be explicit: there is no application detection going on; this just illustrates the sophistication of the algorithm.
We encourage users to experiment with moving the texture preference slider from "Quality" towards "Performance" - you will see huge performance gains with no effect on image quality until the very end, and even then, the effect is hardly noticeable. We are confident that we give gamers the best image quality at every performance level.
Microsoft does set some standards for texture filtering and the company's WHQL process includes extensive image quality tests for trilinear filtering and mipmapping. CATALYST passes all these tests - and without application detection, which could be used if you wanted to get a lower-quality algorithm go undetected through the tests.
Finally, ATI takes image quality extremely seriously and we are confident that we set the bar for the whole industry. We don't undertake changes to our filtering algorithms lightly, and perform considerable on-line and off-line image analysis before implementing changes. This algorithm has been in public use for over a year in our RADEON 9600 series products, and we have not received any adverse comments on image quality in that time. If anyone does find any quality degradation as a result of this algorithm, they are invited to report it to ATI. If there is a problem, we will fix it.
Resposta da ATI, toscamente traduzida
Pra quem não entende inglês, resumidamente:
Eles disseram que é uma tecnologia diferente, que está sendo patenteada, e que as diferenças são percebidas apenas "comparando screenshots apliadas com e sem o algoritmo", e que esse tipo de comparação não é válida para apontar que uma implementação é melhor do que outra.
O algoritmo funciona determinando o quanto diferente um "mipmap" é do próximo, e então aplicando o somente o filtro apropriado (necessário). Eles frisam que em situações atípicas (em que os "mipmaps" são muito diferentes, não é aplicada qualquer otimização.
Frisam também que o driver não detecta a aplicação que está rodando em momento algum, ou seja, o procedimento é o mesmo pra qualquer jogo ou benchmark, o que segundo eles dá uma idéia da sofisticação do algoritmo.
Se alguém perceber qualquer degradação na qualidade de imagem como resultado desse algoritmo, pode reportar isso à ATI. Se há algum problema, corrigiremos.
Driveheaven (http://www.driverheaven.net/#article_13615)
Fonte: ForumPcs
hehehe o q isso ATI!!! Agora ate vc!!! :sm01: :p
A[B]'s