How to filter images with specific dimensions?

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mrwul
Posts: 195
Joined: Tue May 25, 2010 7:01 pm

How to filter images with specific dimensions?

Post by mrwul » Thu Apr 26, 2018 8:46 am

I have downloaded quite a lot of images and would like to delete images below a certain size (LxW),
so they would show up on the monitor, let's say at least as postcard size.

Q: How am I to proceed?

Considering that maybe the dimensions of the images can be small, but because of the high resolution, they still show up as fairly big on the monitor.

Probably I should start off deleting stuff with 200 pixels width?

The printsize does not always correspond with the size on monitor.

Width: 100 x Height:72
# of bit:8
Color mode:RGB
DP:300 x 300
Print siz:8.47x6.10 cm

shows a larger size on the monitor.

Bottom line, frankly, I would not know how to filter/delete small images (on the monitor).

It may sound as a newbie question, I know, but I would really appreciate any recommendations.

Thanks in advance!


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SnagIt-26042018 104037.png

cday
XnThusiast
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Location: Cheltenham, U.K.

Re: How to filter images with specific dimensions?

Post by cday » Thu Apr 26, 2018 10:21 am

You wish to be able to identify images in a folder that you do not want to view from the properties displayed, and then delete them?

One thought: the size of an image on the screen will depend on the View > Auto image size setting, but if you select View > Real size the size on screen will depend only on the image pixel dimensions, I presume...

mrwul
Posts: 195
Joined: Tue May 25, 2010 7:01 pm

Re: How to filter images with specific dimensions?

Post by mrwul » Thu Apr 26, 2018 11:56 am

Eh ...
I want to delete images that are small (smaller than a specific size on screen, e.g. smaller than W 8-10cm H 6-7cm)
Have a -lot- of images, thousands, so my first go is to delete all the small stuff, they are often just a few cm x few cm, so useless.
No idea where to start. Of course, very small size, and low resolution, those are easy to delete, but after that ..

I have set the view to 1:1
Noticed that when I select 'Real size' images are often bigger, at the bottom I see it is, for instance, 133%
Maybe 'Real Size' (with this 133% or so) is not a good idea - it should be just 100% ..?

cday
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Re: How to filter images with specific dimensions?

Post by cday » Thu Apr 26, 2018 12:36 pm

I see now that Real size is not suitable, as images with large pixel dimensions will be too big fit on the screen.

I'm not very familiar with the various viewing options. But is Print size in the image properties actually a relevant parameter, the way you are viewing images? Or are the image pixel dimensions actually the only parameter that matters, enabling you to quickly identify which files to delete?

Edit:

If you are not sure, you could do a simple test by making a copy of an image, and then changing the print size of the copy: do the two files actually display at different sizes on the screen?

mrwul
Posts: 195
Joined: Tue May 25, 2010 7:01 pm

Re: How to filter images with specific dimensions?

Post by mrwul » Sat Apr 28, 2018 4:28 am

To be honest, I would not know -where- else to ask such a complicated question.

Point is that the size on screen does not correspond with the physical size, so, the physical size is of no use.
Likely the screenresolution has something to do with it(??)
Probably (I don't know for sure) a low-res 19" monitor will display an image differently (different size) than a hi-res 27" monitor.
I think there is no such thing as showing dimensions based on screen display.

For example:
I have an image which is 17 cm wide on screen - which is okay, but
when printed the physical width is only 5cm, so the physical width is of no use.

Have no idea how to filter images that are xx cm wide, on screen.

cday
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Re: How to filter images with specific dimensions?

Post by cday » Sat Apr 28, 2018 9:50 am

mrwul wrote:
Sat Apr 28, 2018 4:28 am
I have an image which is 17 cm wide on screen - which is okay, but
when printed the physical width is only 5cm, so the physical width is of no use.

I have no idea how to filter images that are xx cm wide, on screen.
What, ultimately, matters: the image size on the screen, or the size of the printed image? Or are both relevant, which would make life more complicated?

The printed size is shown directly in the file properties shown in your first post.

The image size on the screen will depend on the image pixel dimensions, also shown in the file properties shown in your first post, and also on the particular monitor used, in terms of the monitor diagonal and monitor pixel resolution e.g. 1920×1080.

mrwul
Posts: 195
Joined: Tue May 25, 2010 7:01 pm

Re: How to filter images with specific dimensions?

Post by mrwul » Sat Apr 28, 2018 11:29 am

Important is the image on screen.
(The physical, printed, size, I don't care)

my monitor 2560x1440 (27")

I assume, when an image is, let's say 10cm wide on above 27"monitor, it probably will be displayed larger on a 1920x1080 monitor..?
maybe, 15cm or something.

cday
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Location: Cheltenham, U.K.

Re: How to filter images with specific dimensions?

Post by cday » Sat Apr 28, 2018 11:43 am

mrwul wrote:
Sat Apr 28, 2018 11:29 am
Important is the image on screen.
(The physical, printed, size, I don't care)

my monitor 2560x1440 (27")

I assume, when an image is, let's say 10cm wide on above 27"monitor, it probably will be displayed larger on a 1920x1080 monitor..?
maybe, 15cm or something.
If your monitor is 2560x1440 px and has a 27" diagonal, it should be possible using trigonometry to calculate the pixels per inch of the display, and so calculate the image size on that screen...

mrwul
Posts: 195
Joined: Tue May 25, 2010 7:01 pm

Re: How to filter images with specific dimensions?

Post by mrwul » Sat Apr 28, 2018 12:12 pm

Yes, but then I don't know how to proceed... :?

http://dpi.lv/
2018-04-28_14-06-44.png
2018-04-28_14-06-44.png (54.85 KiB) Viewed 325 times
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Also see a thread about total number of pixels:
viewtopic.php?f=82&t=37392&p=149724#p149724

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cday
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Posts: 1705
Joined: Sun Apr 29, 2012 9:45 am
Location: Cheltenham, U.K.

Re: How to filter images with specific dimensions?

Post by cday » Sat Apr 28, 2018 12:31 pm

cday wrote:
Sat Apr 28, 2018 11:43 am

If your monitor is 2560x1440 px and has a 27" diagonal, it should be possible using trigonometry to calculate the pixels per inch of the display, and so calculate the image size on that screen...

There is actually an easier way, as you have the monitor in front of you, that should be accurate enough:

Measure the width of the visible area of the screen in inches, then divide that figure by the number of pixels in landscape orientation, 2560, and the result should be the number of pixels per inch of that monitor when displaying images at that resolution...

Jochen S.
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Joined: Sun Nov 05, 2017 12:52 pm

Re: How to filter images with specific dimensions?

Post by Jochen S. » Sun Apr 29, 2018 10:53 am

@mrwul:
Just to make sure we are talking about the same: A digital images of defined by pixels which have a color. The size of the image is defined by the number of pixels in x and y dimension. Every information in units like inch or cm is just calculated with the dpi (dots per inch) setting. It says something about the density of pixels during printing. While displaying small images on your monitor just let each pixel of your monitor show one pixel of the image, that is called 100%.

As far as I understood your question you want to delete images with low resolution. So please do not think in "cm" but in pixels. You should view the images at 100% (or lower if the image has more pixels than your monitor) since with values >100% the images will get unsharp.

Did you try to not filter but just sort the images by "image size" (not filesize)? This way the images with the lowest resolution would be first (or last). You can scroll through them and decide up to which resolution you want to keep them.

Regards,
Jochen

mrwul
Posts: 195
Joined: Tue May 25, 2010 7:01 pm

Re: How to filter images with specific dimensions?

Post by mrwul » Sun Apr 29, 2018 1:14 pm

I took me a while to find a workaround...

I am talking about the pixels W multiplied by pixels H
For instance, an image has W 640 pixels H 400 = total pixels 256000

I have a large number of downloaded images want to get rid of 'small' images. Found out that images of roughly 300.000 pixels in total are still okay on my monitor, so all files with total pixels less than this number, I want to delete. Too small.

There is no column of 'total number of pixels' in XnView so I had to do that myself in Excel.
So I exported the list of files (names with their W+H pixel sizes) to Excel, then calculated total pixels sizes there.
In case total pixel size is below 300.000 add 'delete' to the filename, else add 'keep'.
That list I used to have the original file names renamed.

As said, it is a bit of a workaround, but right now I don't know a better way... :)

cday
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Re: How to filter images with specific dimensions?

Post by cday » Sun Apr 29, 2018 2:22 pm

mrwul wrote:
Sun Apr 29, 2018 1:14 pm
There is no column of 'total number of pixels' in XnView so I had to do that myself in Excel.

So I exported the list of files (names with their W+H pixel sizes) to Excel, then calculated total pixels sizes there.
In case total pixel size is below 300.000 add 'delete' to the filename, else add 'keep'.
That list I used to have the original file names renamed.

As said, it is a bit of a workaround, but right now I don't know a better way... :)
Using, in the Browser, Create > File listing... presumably?

Dabola
Posts: 2
Joined: Mon Feb 27, 2017 7:50 am

Re: How to filter images with specific dimensions?

Post by Dabola » Wed May 02, 2018 3:01 pm

Why not sort the file-list by the columns >Width and >Height?
Open the file list (by Ctrl +double-click the image), >View details. (As you already have done:)

Image
>View >Asecending.
>View >Sort by >Image Width (by pixels). And the next time >Image Height. (Or click on the column header).

Then your smallest images in your folder should be at the top of the list.

First mark those where Width are below your limit, 200 pixels. After marking the list then press the header >Height and rapidly see that the marked list seems okay also when the list is sorted by height. It shouldn't take many second to unmark those at the end of the marked list with height over 200. And further on select those less than 200. Then finally delete...

mrwul
Posts: 195
Joined: Tue May 25, 2010 7:01 pm

Re: How to filter images with specific dimensions?

Post by mrwul » Sat May 05, 2018 5:31 am

See attachment, this would be the idea. Hopefully in some next release...

Have submitted this as an idea in the 'Suggestions' section.
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SnagIt-05052018 072445.png
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