[IPOL discuss] [IPOL] new version demo NLmeans

[Antoni Buades]

On 09/03/2011 22:01, Guoshen Yu wrote:
> Hi José Luis, hi Jean-Michel and Toni,
> Thanks very much for asking. I find the interface superb and it would be
> great if our DCT denoising can have a same demo like this. Just two
> remarks/questions.
>
> 1. The denoising algorithm uses a noise sigma parameter. Is this parameter
> estimated from the noisy image or is it simply copied from the interface?
> The noise estimation and the denoiser can be considered as two completely
> different algorithms, whereas the precision of noise estimation has a
> direct impact on the denoiser performance. If this demo is to test the
> denoiser, I think it would be better to directly copy the sigma as if it is
> given. Moreover, in most denoising benchmarks, sigma is assumed known. If
> in this demo the noise sigma is estimated, the comparison with the other
> benchmark results will be unfair, in favor of most other benchmark results.
>
>

Yes, it will take the sigma added as a parameter, without noise estimation.


> 2. I think it would be really great if we can have an interface where a
> number of denoising algorithms are simultaneously and systematically tested
> together. For example, by clicking a button, all the algorithms are
> executed and their results on the same image are displayed one next to the
> other. I would be very happy to have the DCT denoiser bundled with any
> denoising algorithm if possible.
>

I think that's the idea in a second stage.


> Jose Luis, thanks again in advance for implementing the DCT denoiser demo!
>
> Best,
> Guoshen
>
> On Wed, 09 Mar 2011 17:36:25 +0100, José Luis Lisani
> <joseluis.lisani at uib.es>  wrote:
>> The updated version of the NLmeans demo is available:
>>
>> http://demotest.ipol.im/~lisani//bcm_non_local_means_denoising/
>> <http://demotest.ipol.im/%7Elisani//bcm_non_local_means_denoising/>
>> (user: demotest, passw. demotest)
>>
>> The demo features:
>> - subimage selection
>> - result images displayed with a zoom in when they are small (less than
>> 200 pix. in any dimension)
>> - all the images displayed on the same frame
>>
>> It remains a pending issue:
>> the use of 'float' images to prevent the loss of information due to
>> quantization
>> (Nicolas?)
>>
>>
>> @Guoshen: tell me if you like this kind of demo for your dct_denoising
>> algorithm
>>
>>
>> Best,
>> José Luis