0.81 MacOS: Embedded aspect ratio issues

Older bugs which are supposed to be fixed in 0.84. *** Please try to reproduce your bug and confirm the bug fix. ***

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sd_snatcher
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0.81 MacOS: Embedded aspect ratio issues

Post by sd_snatcher » Sat Sep 10, 2016 11:48 pm

When aspect ratio information is present inside PNG, TIF, JPG, BMP etc image files, XnViewMP will show both the thumbnail and the preview with incorrect proportions. Only after you open the image that it will be shown with its correct aspect.

Note: For GIF files, the image will still be shown with incorrect aspect ratio even when you open the files.

Use the following images to test the problem. They can be converted
http://frs.badcoffee.info/images/Zarth-PC88.png
http://frs.badcoffee.info/images/gifsui ... tratio.zip

Tested with XnViewMP 0.81 on Mac OS-X 10.10.5.

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Re: 0.81 Mac: Embedded aspect ratio issues

Post by xnview » Wed Mar 01, 2017 12:50 pm

O.k., thank you, I can also reproduce the problem. Issue 950 is fixed in next version.
Pierre.

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Re: 0.81 Mac: Embedded aspect ratio issues

Post by xnview » Thu Mar 16, 2017 8:48 am

This problem is supposed to be fixed in XnView MP 0.85 beta 1. Please check and confirm the bug fix here.
Pierre.

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Re: XnView MP 0.85 beta 1

Post by sd_snatcher » Mon Apr 03, 2017 9:49 pm

As requested, I tested the embedded aspect ratio bug with 0.85beta2 (Mac) and it's still present.

The files to test the problem can be found in the links bellow:

http://frs.badcoffee.info/images/Zarth-PC88.png
http://frs.badcoffee.info/images/gifsui ... tratio.zip

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Re: XnView MP 0.85 beta 1

Post by xnview » Thu Jun 08, 2017 7:58 pm

Preview is always incorrect?? or only the thumbnail?
Pierre.

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Re: 0.81 MacOS: Embedded aspect ratio issues

Post by sd_snatcher » Sun Dec 31, 2017 12:05 pm

I just tested with XnView-MP v0.88 on Mac OS-X. These are the results:

1) Preview

The aspect ratio is shown correctly for JPG and PNG files. It is still incorrect for GIF files.

But there's a catch: ideally, the image should only be expanded to adjust the aspect ratio, so no pixel information is lost. But XnView is expanding them for changes in the vertical axis, and reducing them for changes in the horizontal axis.


2) Thumbnails in the file browser

The aspect ratio is incorrect for JPG, PNG and GIF files.


To help with the tests, I attached here three files with the same image saved in JPG, PNG and GIF formats. They all have the Pixel Aspect Ratio field set up inside them. In all cases, a black square should be rendered and all images should render the square with the same size.

- If a rectangle is seen, then the aspect ratio info isn't being respected.
- If the size of the rendered rectangle differs between all the rendered versions, then the Aspect Ratio scaler isn't scaling the axes by the same factor.
Attachments
ShouldBeSquare_2x1.png
PNG image with Pixel Aspect Ratio 2:1 set and a square drawn on it.
ShouldBeSquare_2x1.png (716 Bytes) Viewed 623 times
ShouldBeSquare_2x1.jpg
JPG image with Pixel Aspect Ratio 2:1 set and a square drawn on it.
ShouldBeSquare_2x1.jpg (2.34 KiB) Viewed 623 times
ShouldBeSquare_2x1.gif
GIF image with Pixel Aspect Ratio 2:1 set and a square drawn on it.
ShouldBeSquare_2x1.gif (2.39 KiB) Viewed 623 times
ShouldBeSquare_1x2.png
PNG image with Pixel Aspect Ratio 1:2 set and a square drawn on it.
ShouldBeSquare_1x2.png (612 Bytes) Viewed 623 times
ShouldBeSquare_1x2.jpg
JPG image with Pixel Aspect Ratio 1:2 set and a square drawn on it.
ShouldBeSquare_1x2.jpg (3.55 KiB) Viewed 623 times
ShouldBeSquare_1x2.gif
GIF image with Pixel Aspect Ratio 1:2 set and a square drawn on it.
ShouldBeSquare_1x2.gif (1.97 KiB) Viewed 623 times
Last edited by sd_snatcher on Sun Dec 31, 2017 12:41 pm, edited 6 times in total.

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Re: 0.81 MacOS: Embedded aspect ratio issues

Post by sd_snatcher » Sun Dec 31, 2017 12:33 pm

The formula for the GIF pixel aspect ratio can be seen at this link. It goes like this:

In a nutshell, it goes like this:

1) The Gif Aspect Ratio field is present at the offset +12 of the file.

2) The formula for the Pixel Aspect Ratio is this

- If HeaderAspectRatio = 0, then no Pixel Aspect Ratio is defined
- When HeaderAspectRatio > 0, PixelAspectRatio = (HeaderAspectRatio + 15) / 64

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Re: 0.81 MacOS: Embedded aspect ratio issues

Post by xnview » Wed Jan 17, 2018 8:49 am

:bugconfirmed: Thanks to your detailed description I can reproduce the problem.
Pierre.

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Re: 0.81 MacOS: Embedded aspect ratio issues

Post by sd_snatcher » Sun Feb 04, 2018 8:46 pm

It seems that some Pixel Aspect Ratios are still not shown correctly by XnView. Like the one in this attached image.
Attachments
cdfn2c08.png
Image with Pixel Aspect Ratio that doesn't render properly
cdfn2c08.png (404 Bytes) Viewed 570 times

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Re: 0.81 MacOS: Embedded aspect ratio issues

Post by xnview » Tue Apr 17, 2018 12:15 pm

See issue for current status and some details.
Pierre.

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Re: 0.81 MacOS: Embedded aspect ratio issues

Post by xnview » Thu Jun 07, 2018 9:45 am

This problem is supposed to be fixed in XnView MP 0.91. Please check and confirm the bug fix here.
Pierre.

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Re: 0.81 MacOS: Embedded aspect ratio issues

Post by sd_snatcher » Sat Aug 04, 2018 3:18 am

I just tested with XnView-MP v0.91-Beta4 on Mac OS-X. These are the results:

1) Preview

The aspect ratio is shown correctly for JPG, PNG and GIF files now.

But this problem still happens: "ideally, the image should only be expanded to adjust the aspect ratio, so no pixel information is lost. But XnView is expanding them for changes in the vertical axis, and reducing them for changes in the horizontal axis."

I attached a screenshot showing that 2:1 is being rendered much smaller than 1:1 and 1:2 on image view. But they should all be rendered at the same size.

2) Thumbnails in the file browser

The aspect ratio is still incorrect for JPG, PNG and GIF files, as show the attached screenshot.


To help with the tests, I made this page with a set of images. In all cases, all images of the same set (Lennas or squares) should be rendered with the same size.
Attachments
Screen Shot - 2x1 is being rendered much smaller on image view mode.jpg
Screen Shot - distorted thumbnails.jpg

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Re: 0.81 MacOS: Embedded aspect ratio issues

Post by xnview » Sat Aug 04, 2018 9:03 am

sd_snatcher wrote:
Sat Aug 04, 2018 3:18 am
To help with the tests, I made this page with a set of images. In all cases, all images of the same set (Lennas or squares) should be rendered with the same size.
where is the download link for images set?
Pierre.

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Re: 0.81 MacOS: Embedded aspect ratio issues

Post by sd_snatcher » Sat Aug 04, 2018 8:25 pm

The images can be downloaded directly from this page, with right-click:
http://frs.badcoffee.info/PAR_AcidTest

To make things easier, I also attached it here.
Attachments
PixelAspectRatio_tests_image_set.zip
(1.93 MiB) Downloaded 3 times

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Re: 0.81 MacOS: Embedded aspect ratio issues

Post by xnview » Sun Aug 05, 2018 8:05 am

Are you sure that you have 'rebuild thumbnails'?

for preview, 512x256 & 256x512 should be expanded as 512x512 or 256x256?
Pierre.

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