I had the same problem with blurry images on retina displays. I ended up
creating a image component that inside was by default setting source size for
twice the width and height of the item size to have good results on iOS screens.
However......
I have recently found that replacing the pngs for svgs has accelerated the UI
loading time from seconds to a snap!!!
I have found this because I was not finding acceptable the time it took to
resize a window.
I had to replace years of pngs into svgs but in the end it payed off.
You should definitely consider moving to svgs.
Best,
--
Nuno Santos
> No dia 27/03/2021, às 03:17, Alexander Dyagilev <alervd...@gmail.com>
> escreveu:
>
>
> This all is not about my question in any matter. I do not care about SVG at
> all. And SVG are not used in this example.
>
> Please learn to read question before answering....
>
> On 3/23/2021 4:16 PM, Jérôme Godbout wrote:
>> Do you really need to same memory by reducing the source size? I think you
>> should left the source size alone and sample the image from the full source.
>> Source size for SVG doesn’t make any sense, it’s vectoriel, doesn’t have any
>> size, it can scale to any dimension. When playing with the image size (not
>> the source) it will sample the source for each pixel, not sure about the
>> algorithm but you might need an higher source resolution to get a proper
>> image without artifact. I would at least take the Screen.devicePixelRatio
>> into the source size into account and even add a x2 to ensure proper
>> sampling, but I don’t see any real advantage to play with the source size
>> unless you really are consuming way too much memory.
>>
>> This might slow you down if the same image is using different sourceSize:
>>
>> Note: Changing this property dynamically causes the image source to be
>> reloaded, potentially even from the network, if it is not in the disk cache.
>>
>>
>>> On Mar 23, 2021, at 3:31 AM, Alexander Dyagilev <alervd...@gmail.com> wrote:
>>>
>>> Hello,
>>>
>>> We had a strange problem with blurred images under Retina displays. Left
>>> part of the image - before, right one - after the fix.
>>>
>>> <pjcgokflkeakcklh.png>
>>>
>>> Our QML code was using with to show images:
>>>
>>> Image {
>>> anchors.verticalCenter: parent.verticalCenter
>>> sourceSize.width: 25
>>> sourceSize.height: 25
>>> source: preview.url
>>> }
>>>
>>> I've tried to multiply sourceSize by Screen.devicePixelRatio - images
>>> became bigger so they did not fit their places.
>>>
>>> Then I've replaced sourceSize.width with just width and the same for
>>> height. And it works fine now.
>>>
>>> My questions is:
>>>
>>> 1) Is it required to multiply sourceSize by devicePixelRatio? Or is it
>>> managed automatically? It seems that it is managed automatically for PNG
>>> and NOT managed for SVG.
>>>
>>> 2) If it is already managed automatically for PNG (these images preview.url
>>> are PNGs) then why was it blurred? The original PNG image is of size 64x64
>>> pixels under Retina displays.
>>>
>>> _______________________________________________
>>> Interest mailing list
>>> Interest@qt-project.org
>>> https://lists.qt-project.org/listinfo/interest
>>
>> Jerome Godbout
>> Software/Firmare Lead Amotus
>>
>> C: (581) 777-0050
>> O: (418) 800-1073 ext.: 114
>> godbo...@amotus.ca
>>
>> <image007.png>
>>
>>
>> dimonoff.com | amotus.ca
>>
>> We have moved!
>> 1015 Avenue Wilfrid-Pelletier, Québec, QC G1W 0C4, 4e étage
>>
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