No smooth contour.

[Designer1]

I have raised the issue here in the forum several times, unfortunately the export quality of PNG is not very smooth. Here is an example from circles. Open this graphic in Affinity Photo in 100% size. The contour is somewhat unclean, especially at extreme points. I am using Designer 1.10.5.

[DWright]

This is not a bug Affinity Photo and the PNG file format are raster based and you will get pixilation on the circle when zoomed in, to have this as a smooth curve you will need to use Designer and export to a vector format such as svg. 

[Designer1]

3 hours ago, DWright said:

This is not a bug Affinity Photo and the PNG file format are raster based and you will get pixilation on the circle when zoomed in, to have this as a smooth curve you will need to use Designer and export to a vector format such as svg. 

That is completely clear. But I need a perfect PNG for presentations. I have the impression that PNG export has become better in version 1.10.5. Still not perfect. The contours in PNG are a bit irregular. It would be nice if this were improved.

[R C-R]

3 hours ago, Designer1 said:

The contours in PNG are a bit irregular.

What specifically do you mean by irregular? Are you talking about antialiasing effects along the edges of the circle, stair-stepped edges if no antialiasing is applied, or something else?

Keep in mind that each pixel in a raster image can have only one color, so no edge pixel can be split into smaller parts to display more colors to get smoother looking results.

[Designer1]

13 hours ago, R C-R said:

What specifically do you mean by irregular? Are you talking about antialiasing effects along the edges of the circle, stair-stepped edges if no antialiasing is applied, or something else?

Keep in mind that each pixel in a raster image can have only one color, so no edge pixel can be split into smaller parts to display more colors to get smoother looking results.

I have enlarged the example to 400% to demonstrate the problem. At extreme points, the export quality of round shapes is not good.

[walt.farrell]

Perhaps your issue is that Affinity Circles are not mathematically precise Circles? That has been discussed previously.

[Designer1]

7 minutes ago, walt.farrell said:

Perhaps your issue is that Affinity Circles are not mathematically precise Circles? That has been discussed previously.

No. It's about export quality of vector graphics to PNG and JPG. For straight shapes quality is perfect, for round shapes unfortunately not.

[Old Bruce]

4 hours ago, Designer1 said:

No. It's about export quality of vector graphics to PNG and JPG. For straight shapes quality is perfect, for round shapes unfortunately not.

It is the nature of pixels. Absolutely nothing can be done to 'improve' them. Don't look at the PNGs at 400%, look at them at 100%. 

[NotMyFault]

It seems someone is obsessed with non-existing issues of export quality. Started with font rendering, now switched to circles. What will be next? Issues with raster export of heart symbol?

[R C-R]

1 hour ago, Old Bruce said:

It is the nature of pixels. Absolutely nothing can be done to 'improve' them.

Thus, the only way to mitigate this is to increase the number of pixels in the raster image export, increasing the file size.

[Designer1]

16 hours ago, NotMyFault said:

It seems someone is obsessed with non-existing issues of export quality. Started with font rendering, now switched to circles. What will be next? Issues with raster export of heart symbol?

It may be that you think the export quality of PNG is perfect. That is not yet a reason to portray other opinions as ridiculous.

[firstdefence]

Can you give an example of an export to png that is of higher quality or as you would expect or like it to be?

[NotMyFault]

Mal auf gut Deutsch: Die Affinity apps benutzen genau dieselben Algorithmen wie alle anderen Apps um aus Vektor-Objekten Raster Dateien zu erzeugen. Es gibt minimale Unterschiede, die aber keinesfalls einen irgendwie gearteten Qualitätsunterschied bedeuten. Die Exporte sind nach meinem fachlichen Verständnis (ich bin Diplom-Informatiker und habe selbst Grafik-Routinen programmiert und jahrelang gut von SW Entwicklung gelebt) absolut korrekt. Das heist nicht das Affinity Apps keine Fehler aufweist, die liegen nur an anderen Stellen.

 

Du hast, wie Du selbst im Post erwähnst, vielfach die Export-Qualität bemängelt, ohne jemals einen nachvollziehbaren Nachweis zu liefern. Es ist Dir also noch nicht gelungen, auf technisch nachvollziehbarer Weise aufzuzeigen, was genau das Problem ist, oder wie die Exporte Deiner Meinung nach korrekt aussehen müssten.

Daher sollte es nicht wundern, wenn andere langsam genervt reagieren, wenn immer wieder die gleiche substanzlose Generalkritik von Dir wiederholt wird.

[firstdefence]

Just for comparison, this is the png opened in Adobe Illustrator v24.1

[PaulEC]

I wonder if the attached image shows the difference between what is considered as "good" and "bad" PNG images in APhoto?

If so, they are both enlargements of the same sized torus. The only difference is that the top image is 72dpi and the lower one is 300dpi.

 

[Designer1]

46 minutes ago, NotMyFault said:

Mal auf gut Deutsch: Die Affinity apps benutzen genau dieselben Algorithmen wie alle anderen Apps um aus Vektor-Objekten Raster Dateien zu erzeugen. Es gibt minimale Unterschiede, die aber keinesfalls einen irgendwie gearteten Qualitätsunterschied bedeuten. Die Exporte sind nach meinem fachlichen Verständnis (ich bin Diplom-Informatiker und habe selbst Grafik-Routinen programmiert und jahrelang gut von SW Entwicklung gelebt) absolut korrekt. Das heist nicht das Affinity Apps keine Fehler aufweist, die liegen nur an anderen Stellen.

 

Du hast, wie Du selbst im Post erwähnst, vielfach die Export-Qualität bemängelt, ohne jemals einen nachvollziehbaren Nachweis zu liefern. Es ist Dir also noch nicht gelungen, auf technisch nachvollziehbarer Weise aufzuzeigen, was genau das Problem ist, oder wie die Exporte Deiner Meinung nach korrekt aussehen müssten.

Daher sollte es nicht wundern, wenn andere langsam genervt reagieren, wenn immer wieder die gleiche substanzlose Generalkritik von Dir wiederholt wird.

Das ist keine generelle Kritik. Als Diplom-Designer bin ich darauf angewiesen, dass die für Kunden exportierten Grafiken von hervorragender Qualität sind und feine typografische Details perfekt dargestellt werden. Leider ist die Qualität in einigen Fällen nicht ganz zufriedenstellend. Ob dies an Antialiasing oder anderen technischen Faktoren liegt, kann ich nicht beurteilen. Ich würde mich freuen, wenn dies verbessert werden könnte.
Ansonsten ist Affinity Designer eine wirklich tolle App mit vielen praktischen Funktionen.

[User_783649]

As far as I can remember, we already figured out earlier (in the previous topics) that @Designer1 also experienced poor text rendering and exports on his machine. By providing pixel-to-pixel accurate image samples some of the forum members (including myself) proved that there's no similar edge rendering problems on their machines (mostly Macs).

I should admit there are very subtle differences in how vector shapes are rendered between Affinity and Adobe apps. In 99% of cases you will only notice them if you really want to notice them. But they do exist.

Let's do a kind of double blind test (any hardcore audiophiles here?). Can you easily tell which one is made in Affinity?

[JIPJIP]

On 3/12/2022 at 11:16 AM, Designer1 said:

I have enlarged the example to 400% to demonstrate the problem. At extreme points, the export quality of round shapes is not good.

This is the best possible representation of a circle in a bitmap format (like png or any other bitmap format) at the resolution you choosed when creating it. (As opposed to vector format which describes shapes mathematically and are rasterized on the fly at the displayed resolution). This is not a bug. This is how a circle can be antialised at this resolution and this is the best every existing software can do at this resolution.

The best way to increase quality with a bitmap image like this is to increase resolution when creating your circle (or converting it from a vector format to a bimap format) and choose a resolution adapted to (or larger than) your final work.

If you want to be resolution independent you have to work in vector format.

[Designer1]

1 hour ago, Alex M said:

As far as I can remember, we already figured out earlier (in the previous topics) that @Designer1 also experienced poor text rendering and exports on his machine. By providing pixel-to-pixel accurate image samples some of the forum members (including myself) proved that there's no similar edge rendering problems on their machines (mostly Macs).

I should admit there are very subtle differences in how vector shapes are rendered between Affinity and Adobe apps. In 99% of cases you will only notice them if you really want to notice them. But they do exist.

Let's do a kind of double blind test (any hardcore audiophiles here?). Can you easily tell which one is made in Affinity?

The quality seems to be better on the Mac than on Windows. Is the first circle of Affinity?

[kaffeeundsalz]

1 hour ago, Alex M said:

Let's do a kind of double blind test (any hardcore audiophiles here?).

Off topic: Most hardcore audiophiles don't give a damn about double-blind listening tests. They simply claim they can hear a difference.

[firstdefence]

1 hour ago, Alex M said:

As far as I can remember, we already figured out earlier (in the previous topics) that @Designer1 also experienced poor text rendering and exports on his machine. By providing pixel-to-pixel accurate image samples some of the forum members (including myself) proved that there's no similar edge rendering problems on their machines (mostly Macs).

I should admit there are very subtle differences in how vector shapes are rendered between Affinity and Adobe apps. In 99% of cases you will only notice them if you really want to notice them. But they do exist.

Let's do a kind of double blind test (any hardcore audiophiles here?). Can you easily tell which one is made in Affinity?

The most likely answer is, both are, the suggestion that one is from affinity creates a subjective difference. 😉

[User_783649]

@Designer1 Correct! First one is from Affinity Designer and second one is from Adobe Photoshop. You have a really good trained eye and can easily spot the difference. From my experience, in general, rendering quality of Affinity apps is better on Mac. I remember our last discussion with you about difference in type rendering quality. I still believe there's a room for improvement for Windows versions of these wonderful apps in this particular aspect.

@kaffeeundsalz I like where you're going with that! So true. The real question is – should we always focus on recognizing these 0.00X% differences or we can just relax and enjoy our favorite music. What it is all about in the end of the day?

@firstdefence Really dig into philosophic aspect of this, thanks! Maybe it is not better or worse. Just subjectively... different?

[R C-R]

8 hours ago, Designer1 said:

It may be that you think the export quality of PNG is perfect.

I think that what @NotMyFault was trying to say is that the quality of a PNG file unavoidably depends on its pixel resolution (the total number of pixels in the raster image); thus, it can never be "perfect" in the same resolution-independent way a vector object can be.

IOW, the PNG will always be imperfect in some way when compared to a pure vector version of the same type of object. 

[NotMyFault]

45 minutes ago, R C-R said:

I think that what @NotMyFault was trying to say is that the quality of a PNG file unavoidably depends on its pixel resolution (the total number of pixels in the raster image); thus, it can never be "perfect" in the same resolution-independent way a vector object can be.

IOW, the PNG will always be imperfect in some way when compared to a pure vector version of the same type of object. 

While what you explain is ok for me, it was not what I intended to say.

The export result is in line what I expect from rasterising algorithms will provide. The barely noticeable differences at aliased edge pixels are the product of design choices, probably caused by rounding. If you move the circle center point, change the radius or stroke width by only a fraction of the pixel size, e.g. 1/10th of a pixel, you will get bigger rendering differences within Affinity or Photoshop, compared to the rendering difference between both Apps.

So there is a very slight difference, but it is no "quality" difference except you say Photoshop rules the world.

If D1 customers except a result 100% identical to Photoshop, then no other application can deliver this result.

Anti-Aliasing and other methods to improve (visible / perceivable) smoothness of raster images created from vectors are no exact science. It is a field of subjective design choices, and up to the App vendor to choose one of the well established methods. Actually, you would need to know the output device (LCD/LED, CRT, laser/inkjet printer, offset print etc) to choose the "best" AA method for every output device. For LCD/LED displays, you would need to know the RGB pattern sub-pixels to provide the "best" AA method. The method will even depend on zoom level used during display.

In times of at least 4K "retina" displays a discussion about AA differences does not make much sense. If you want to discuss, you would need to dig much deeper in the viewing situation.

There is a good reason why Windows allows users to individually adjust the "clear type" settings (since about Windows XP, 7, Vista, 10, and still in 11), based on a series of test renderings. It is a highly subjective personal choice. 

[NotMyFault]

1 hour ago, LondonSquirrel said:

To clarify rendering... do you mean the output (i.e. the file) or the display (what is shown on screen)?

If you take the same file, and output using the same settings, on a Mac and a Windows machine, but view both files on the Mac, can you see a difference then?

If Windows and Mac would deliver different exports from the same files, it would be actually a bug.

The only difference which might cause differences in exported files could be coming from fonts, which might share the same name, but could be slightly different depending on OS - they are delivered by OS or third party, not by Affinity