[digiKam-users] why is batch convert to bw so extremely slow?

[Daniel Bauer]

Am 01.07.20 um 16:08 schrieb Gilles Caulier:
> Hi Daniel,
> 
> Did you activate Multicore support in BQM ?

Hi Gilles,

where do I find that setting?

> 
> Le mer. 1 juil. 2020 à 16:07, Daniel Bauer <linux at daniel-bauer.com> a écrit :
>>
>>
>>
>> Am 01.07.20 um 07:42 schrieb Maik Qualmann:
>>> Saving large PNG files takes so long, Gimp is not faster either. Are you sure
>>> you saved it as a PNG in the editor and not as a JPG? If versioning is active,
>>> "Save changes" creates a JPG depending on the setting, which is very fast. If
>>> you want to have a JPG in BQM, you have to attach the tool for saving in JPG
>>> at the end of the tools.
>>>
>>> Maik
>>
>> I use to work with png. The difference I see is between the batch tool
>> and the edit tool. Of course, saving "save as png" takes a bit, but
>> compared to the batch tool it is extremely much faster.
>>
>> There is no versioning active. It reads the original png, converts to
>> bw, then saves in a subfolder as png. This takes 2 to 3 minutes per
>> image, which is really long.
>>
>> Doing the same manually, also in digikam: in album click on image to
>> open editor, color: convert to bw, save as png... is at least ten times
>> faster, but needs a lot of clicks and is very boring - and ideal job for
>> a batch process. But I had to do it manually because I didn't want to
>> wait almost 3 hours...
>>
>> I know that highly compressed png take more time, but in settings I have
>> set png compression to 5, and I think, the batch process uses that
>> compression, too. Or not?
>>
>>>
>>> Am Dienstag, 30. Juni 2020, 20:11:56 CEST schrieb Daniel Bauer:
>>>> Hi,
>>>>
>>>> Sometimes I'd like to convert a complete album to bw. I added 69 color
>>>> png of 30-40MB to a batch, selected convert to bw, save in new folder, run.
>>>>
>>>> Each image takes more tan 2 minutes to convert. When I open it in
>>>> editor, and click color->bw it works immediately, also saving the file
>>>> is fast. But batch processing is so slow that it cannot be used.
>>>>
>>>> Now I must go through the album in editor, click color->bw->save->next
>>>> 68 times, which is not comfortable but at least 10 times faster :-(
>>>>
>>>> Why?
>>>
>>>
>>>
>>>
>>
>> --
>> Daniel Bauer photographer Basel Málaga
>> https://www.patreon.com/danielbauer
>> https://www.daniel-bauer.com

-- 
Daniel Bauer photographer Basel Málaga
https://www.patreon.com/danielbauer
https://www.daniel-bauer.com