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#1 2018-11-27 22:57:12

psh
Member
2018-11-13
11

How to improve quality of thumbnails and pics

Hello/Hi/Greetings,

I’m using the dark theme but the thumbnails and pics (after clicking on a thumbnail or starting the slideshow) are noticeably softer than in the modus theme (I don’t want to use modus because there are some compatibility issues with the User Collections plugin).

Is there a way to get the same quality of thumbnails/pics in the dark theme (or generally spoken in other themes) as in the modus theme?

I use the current version of Piwigo.

Thanks,
Peter

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#2 2018-11-29 07:49:00

eliz82
Member
Romania
2016-04-27
240

Re: How to improve quality of thumbnails and pics

I'm not 100% sure that I understand what are u talking about, but there is a logical explanation for image softening.

In the past browsers used to not be influenced by the DPI setting in the operating system. Then they implemented text to be resized by that setting.
Recently with the apparition of high-dpi display, browsers also added images to the list ... and this there started to be problems with image softness. (in firefox for example OS dpi scaling can be disabled in advanced settings https://support.mozilla.org/en-US/questions/1120822)

-So if an image is the same size as container, it will be normally showed at 1:1 if DPI is 100%. if you set DPI to 125% in the operating system then the image will be upsized to 125% and will start to look soft.

-If an image is lager then the container, it will be downsized if DPI is 100% and will still look almoast as sharp as displayed to 1:1. if DPI is 125% will be showed closed to 1:1 and it will look sharp.

So the solution to not have soft looking images in modern browsers is to put images larger then the container. See print screen.


Uploaded Images

Last edited by eliz82 (2018-11-29 07:51:23)

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#3 2018-11-29 18:04:19

psh
Member
2018-11-13
11

Re: How to improve quality of thumbnails and pics

Hi eliz82,

thank's for your reply. You're totally right with what you wrote and I could reproduce it in Firefox by disabling dpi scaling as you suggested.

But what I've meant is that - when using the same settings in Windows and my browser - the same picture looks nice and sharp when using the Modus theme and rather soft (of poor quality) when using the dark theme. You can easily see the difference, even when you save the pics right from the screen with the snipping tool.

That's why I think it must have something to do with the piwigo/theme-settings as well and why I asked if I can change something in the piwigo or (dark) theme settings.

Thanks,
Peter

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#4 2018-11-30 21:51:49

psh
Member
2018-11-13
11

Re: How to improve quality of thumbnails and pics

I've saved from the same pic displayed once as thumbnail and once as normal sized picture with right-click a jpg, both from the dark theme and the Modus theme. These are the dimensions of the jpgs:

Dark theme:

Thumbnail: 144 x 95 Pixel, 240 dpi
Picture: 792 x 525 Pixel, 240 dpi

Modus theme:

Thumbnail: 432 x 286 Pixel, 240 dpi
Picture: 1656 x 1099 Pixel, 240 dpi

I suppose that's the reason for the quality difference. So is there a possibilty to change the settings to increase the resolution of the thumbnails and pics displayed in the galleries in the dark theme (or in other themes) like in Modus theme? If yes how do I have to do it?

Thanks,
Peter

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#5 2018-12-01 02:28:10

executive
Member
2017-08-16
399

Re: How to improve quality of thumbnails and pics

psh wrote:

So is there a possibilty to change the settings to increase the resolution of the thumbnails

config - options - photo sizes

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#6 2018-12-01 08:49:42

psh
Member
2018-11-13
11

Re: How to improve quality of thumbnails and pics

Hi executive,

thanks for your reply; unfortunately this makes the pics just bigger and not sharper?!

Best regards,
Peter

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#7 2018-12-03 12:58:37

eliz82
Member
Romania
2016-04-27
240

Re: How to improve quality of thumbnails and pics

psh wrote:

Dark theme:
Thumbnail: 144 x 95 Pixel, 240 dpi
Picture: 792 x 525 Pixel, 240 dpi

Modus theme:
Thumbnail: 432 x 286 Pixel, 240 dpi
Picture: 1656 x 1099 Pixel, 240 dpi

I suppose that's the reason for the quality difference. So is there a possibility to change the settings to increase the resolution of the thumbnails and pics displayed in the galleries in the dark theme (or in other themes) like in Modus theme?

No, it's not. Resolution alone have nothing to do with this. It's the fact that photo is in a smaller container then it's resolution make the image look sharp in modus. See the print screen from previous post.

If the thumbnail 144x95 it show at 1:1 in 100% dpi, for 150% it will be upsized. Changing resolution to a 300px will not help. The 300px version will be upsized also.
You could try some little CSS modifications of your theme. For example set the thumbnail 250px and set the container width to 144px or 66%. Then your picture will look sharp also on display with DPI set to something like 150%.

P.S. that 240 dpi is irrelevant. it's written in metadata of the image is only used by printer software when a user is printing something but not choosing dpi or a scaling to paper size. you are just saying to the printer that you want 240 pixel in 1 inch (by default). so if you have a 2400px image it will be print on 10 inches of paper.

Last edited by eliz82 (2018-12-03 17:12:10)

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#8 2018-12-06 20:55:33

psh
Member
2018-11-13
11

Re: How to improve quality of thumbnails and pics

Hi eliz82,

thank you for your help. I've tried it a little bit but I have to admit I am not skilled enough to get the css code lines right. Can you again assist me here with some useful tips or even better with the correct css code itself?


Thanks,
Peter

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