Calculate the real aspect ratio of an image

[sinus]

Hi all
Does someone know a possibility to calculate the aspect ratio (like 3:2 or 16:9) of an image with help of the variables with the math-functions?
Means variables like

Code Select Expand

{File.LongEdge|cast:int;math:div,{File.ShortEdge|cast:int}}

But this one works not.
Maybe it is simply not possible.

But maybe someone has an idea?

[herman]

Wouldn't {File.AspectRatio} be easier to use?

[sinus]

Thanks, Herman, for your intput.

Unfortunately this variable ({File.AspectRatio}) works only for uncropped images.
As soon I have altered them with Photoshop, it shows a completely wrong number (e.g. 4:3, thougth is is 16:9) or it shows simply a 0 (null).

At least on my images, I do not know, when and with what value this variable is feeded, but here it works only for new images.

That is why I am searching a better way.

[Mario]

The aspect ratio is calculated from the physical width and height of the file, as returned by the image library.
The same values you see in IMatch and returned by {File.Width} and {File.Height}. Are these variables correct for your image?
When I crop a 16:9 image to 5:4 in Ps, IMatch afterwards also displays 4:5 for the {File.AspectRatio}

[sinus]

The aspect ratio is calculated from the physical width and height of the file, as returned by the image library.
The same values you see in IMatch and returned by {File.Width} and {File.Height}. Are these variables correct for your image?
When I crop a 16:9 image to 5:4 in Ps, IMatch afterwards also displays 4:5 for the {File.AspectRatio}

Thanks, Mario

The variables {File.Width} and {File.Height} are correct, but not the {File.AspectRatio}, as you can see in my attachement.
After cropping in PS Aspect Ratio shows 0.

I checked this also in VarToy, it is the same.
The Variable what I used:

Code Select Expand

{File.Width|pereplace:.==} x {File.Height|pereplace:.==}
{File.Width|numcomp:gt,{File.Height},Q,H}
{File.AspectRatio}

That is the reason, why I want to calculate the real AspectRatio.

[Mario]

The pixel dimensions you have used match none of the standard a:b ratios. Hence the variable returns 0.
Your variable should be {File.LongEdge|cast:int;math:div,{File.ShortEdge|cast:int},2}. The cast is implicit with math and if you don't specify the digits parameter, 0 decimal digits is assumed.

Since, for example, 2548 / 800 gives 3.21, the variable returns 3 if digits=0 and 3.21 if digits=2

[sinus]

Mario, brilliant!

Thanks for your input. This was a great help. Now I get good and correct results! 

Now I get e.g. 3.67 as a result and I have lerned somewhere on the net to count further with "Verhältnisse berechnen"  I think, finally I will get a good result.

I have to know this, because specialy one client does layouts, where he ask for aspect ratios like 3:4, but also 16:9 and 12:7).

[Mario]

I have enhanced the {File.AspectRatio} variable a bit for the next release.

[sinus]

I have enhanced the {File.AspectRatio} variable a bit for the next release.

Thanks, Mario, cool!