Histogram for images online

[Dave Humphries]

Does anyone know of a website that has the ability to paste a url for an image into a box and have it display a histogram of the image content?

I ask because I would find such a feature useful to save downloading the image to my HDD, then opening it in an image editing program like Elements, etc. Also, for use when at work where I have no Image editor (to speak of).

e.g. like you can here for EXIF data?

[Steaphany]

A quick google returned this:

Photo Histograms Everywhere!

is that what you were looking for ?

[Steaphany]

I tried the Histograms Everywhere and it works great, except for here on CiC. The Javascript that pops up an enlarged photo gets in the way. The plain images that are in the tutorials work fine with Histograms Everywhere. The admins may need to get the Histograms Everywhere source, available from the link I posted, to integrate it with the web site.

It is a nice handy tool to have and it would be useful to our whole community

[Dave Humphries]

Hi Steaphany,

That looks promising, although I was thinking of something that doesn't require installing anywhere - i.e. someone already has it and is magnamimous (sp?) enough to provide the bandwidth for people to use it where they host it.

oh, and I'll take 'the moon on a stick' while we're there

I'm at work at the moment, but will have a closer look at home tonight, in about 6+ hours.

I tried the Histograms Everywhere and it works great, except for here on CiC.

I wonder if it's because the urls for the images hosted at CiC (e.g. attachments and albums) are BB code links and don't end in a normal image file extension?

Thanks,

[Dave Humphries]

Hi again Steaphany,

I tried the Histograms Everywhere and it works great, except for here on CiC. The Javascript that pops up an enlarged photo gets in the way. The plain images that are in the tutorials work fine with Histograms Everywhere. The admins may need to get the Histograms Everywhere source, available from the link I posted, to integrate it with the web site.

It is a nice handy tool to have and it would be useful to our whole community

Ah, Now I have had a bit more time, yes, it is exactly what I was looking for (and developed for same reason).

I have tried it in both FF and IE.

As you say; for images viewed on other sites, it can work very well indeed - Just click the bookmark (the one you dragged from the website to browser toolbar), then click the image, just two clicks is all it takes - couldn't be much simpler - if only it worked here (where I need it most).

If you open the image in a new tab or window, it works better in FF.

Normally in FF, as you say, the Lytebox code seems to scupper it, but in IE, they share resources and it sorta works behind the Lytebox, so when that is cleared and you scroll across, it is visible.


Many thanks,

[Steaphany]

Dave,

I haven't reviewed the Histograms Everywhere or Lytebox code, but could the two be integrated so that the Histograms Everywhere button is in the border surounding the Lytebox pop up window ? Of course it would be beneficial if the server side php could be hosted from the CiC server as well. Then anyone viewing an image here would be able to call up the histogram whether hosted on CiC or referenced to an externally hosted image link.

[MiniChris]

Steaphany...let me know if you do not recieve a private message from me concerning free wet darkroom equipment.

[Steaphany]

Chris, I just replied

[Dave Humphries]

Hi Steaphany,

I checked it on one of Donald's white bordered shots and it seemed to show over exposure/clipping more than seemed evident in the picture, I think we may need to check accuracy, or at least compare to what Elements or CS5 displays.

No time to look out the url now.

[Donald]

Hi Steaphany,

I checked it on one of Donald's white bordered shots and it seemed to show over exposure/clipping more than seemed evident in the picture,

For what it's worth (as you folks have a much better technical undersatnding that I do), that border on my images is at 243 rather than 255. So I wouldn't have thought it should induce a histogram showing clipping.

[Steaphany]

Donald's white bordered shots and it seemed to show over exposure/clipping

I'm suspecting that Histogram Everywhere examines the whole file, not just a centered image surrounded by a frame and this would make any photo with an artistic border or other presentation related elements display a histogram inclusive of and biased by these elements. I'm wondering how hard it would be to add code to identify framing and borders to eliminate them from the histogram calculations.

As Donald mentioned, he uses a border white value of 243, which could easily show a significant peak on the right edge of the histogram. I'll have to review the code to see if once the image has been number crunched, if any scaling is done prior to displaying the histogram which would explain why the 243 looks as it did for you.

At least the full source is available to go over and play with.

[Dave Humphries]

Hi all,

When we had this discussion, I dropped a line to Jeffrey Friedl, the builder of my favourite online EXIF tool, about this and he has actually added the feature today

To use
Click link; http://regex.info/exif.cgi to open "Jeffrey's Exif Viewer"
Paste a URL into top box (or Browse you HDD in lower)
Click adjacent button
When page opens, if present, EXIF data will be displayed
Below the image thumbnails are the words "click to show histogram"
Do as it says and you see a little RGB histogram

I'm quite chuffed,

[rob marshall]

I use this one for Firefox. It works really well. You just right-click an image and select 'show histogram of image' and up it pops. You can select all channels, or individual colour channels. It gives some statistics on the light spread, which is quite useful.

https://addons.mozilla.org/en-US/firefox/addon/8767/

[Dave Humphries]

I use this one for Firefox. It works really well. You just right-click an image and select 'show histogram of image' and up it pops. You can select all channels, or individual colour channels. It gives some statistics on the light spread, which is quite useful.

https://addons.mozilla.org/en-US/firefox/addon/3905/

Hi Rob,

I have that installed and use it, but I don't seem to have the 'show histogram of image' option you refer to

[rob marshall]

Hi Rob,

I have that installed and use it, but I don't seem to have the 'show histogram of image' option you refer to

Try closing and reloading Firefox. When you hover over a posted image you should have the option on right-click. If you still can't see it check it's installed using TOOLS/ADD ONS. Another good thing it does is if you mouse over the 0-255 bar it tells you the count for a specific tonal value.

Can you see it now?

[Dave Humphries]

HI Rob,

OK, installed via add-ons and restarted.

Image on left is right click menu of an image in CiC thread and on the right is right click menu of an image in EXIF viewer installed from yur link.



Why is it not working?

[rob marshall]

Dave

When you open addons (TOOLS/ADDONS) do you get Histogram Viewer listed?

What version of Firefox are you on? I'm on 3.6.13. Which I think is the latest.

This is the right-click menu on mine



and this is the viewer in action. If you are on the latest version of Firefox try uninstalling and re-installing the addon. Maybe something got screwed up when loading. I notice on the web page it says version 1.55 but my installed version is 2.03. Maybe they just haven't updated the webpage though.

Can someone else try this to see if they have problems? https://addons.mozilla.org/en-US/firefox/addon/8767/

[Donald]

Rob

Is your link not to the EXIF viewer as opposed to the Histogram viewer? Is the link to what you're referring to not, https://addons.mozilla.org/en-US/fir...=all&x=17&y=17

I already have the EXIF viewer and can't find how to access a Histogram from it.

[rob marshall]

Argh! My mistake - I got the wrong page. Humble apologies - don't tell Katy This is the correct one....https://addons.mozilla.org/en-US/firefox/addon/8767/

I'll change the other links above.

Many thanks.

Rob

Is your link not to the EXIF viewer as opposed to the Histogram viewer? Is the link to what you're referring to not, https://addons.mozilla.org/en-US/fir...=all&x=17&y=17

I already have the EXIF viewer and can't find how to access a Histogram from it.

[Donald]

Katy ......