Re: [css3-images] image-rendering property for contrast-preserving image upscaling

On Thu, Dec 2, 2010 at 6:34 PM, Robert O'Callahan <robert@ocallahan.org>wrote:

> On Fri, Dec 3, 2010 at 3:13 PM, Gregg Tavares (wrk) <gman@google.com>wrote:
>
>> On Thu, Dec 2, 2010 at 5:59 PM, Robert O'Callahan <robert@ocallahan.org>wrote:
>>
>>> On Thu, Dec 2, 2010 at 3:04 PM, Tab Atkins Jr. <jackalmage@gmail.com>wrote:
>>>
>>>> Gimme a name for the new value and I'll add it to Image Values.
>>>>
>>>
>>> I think sometimes authors explicitly want nearest-neighbour (e.g. to
>>> expose the pixel data of an image, perhaps in an editor), so we might want
>>> to provide 'nearest-neighbor' explicitly.
>>>
>>> For what James described as "optimize-contrast", maybe
>>> "optimize-contrast" is the best name. Or maybe "preserve-contrast".
>>
>>
>> I agree. I don't understand "optimize-contrast"
>>
>> Does that mean If I have 5 pixels black,red,blue,green,white and I scale
>> to 10 pixels I'll get
>>
>> black,black,red,redish-purple,bluish-purple,blue,blueish-green,green,white,white
>> since by some definitions there is no contrast between red,green,blue so
>> those would be blended
>>
>> Why not just say "nearest-neighbor" if that's the effect people are asking
>> for?
>>
>
> For some use-cases, e.g. emulators, we want to allow scaling algorithms
> more elaborate than nearest-neighbor, like the ones Tab linked to earlier.
>

I understand that but suspect the user or the developer would want to choose
the algorithm, not leave it up to the browser. If the browser chooses the
wrong one the results will not be pleasant. Different algos work better with
different content. The UA has no way of knowing which is best for a given
piece of content or page.


>
> But one option is to tell those authors to implement their own scaling
> algorithms in WebGL.
>
> Rob
> --
> "Now the Bereans were of more noble character than the Thessalonians, for
> they received the message with great eagerness and examined the Scriptures
> every day to see if what Paul said was true." [Acts 17:11]
>