Addon: RGB Histogram

[kevincrafts]

This addon will create a RGB Histogram for color images and a Luminosity Histogram for grayscale photos. Options include whether you want a combined/overlayed histogram (red, green, and blue channels overlayed on each other) or a stacked histogram (red, green, and blue channels separated) and the background color for the histogram. The histogram tends to be weighted towards the dark end on dark photos but the shape is still relatively the same compared to Photoshop.

Instructions:

1. Add admin_RGBhistogram to your addons directory.
2. Add histograms directory to your pixelpost directory and make it writable.
3. Add $lang_histogram = "<h2>Histogram</h2>"; to your language file.
4. Create histograms through the edit image menu by clicking on the RGB Histogram submenu (next to EDIT POST). Choose your background color and type and press the Create Histogram button.
5. Place <RGBHISTOGRAM> on your image_template.html file to display histogram.

See a Demo (http://blog.kevincrafts.com) - click on info & comments to see histogram

Download (http://www.pixelpost.org/extend/addons/rgb-histogram/download/)

[Dkozikowski]

This may be one of the coolest addons i've seen in a while.

Great job. It worked well in my test environment.

Just a suggestion for future updates/releases. Throw in a delete function so it's easy for one to remove the histogram file from the image.

Thanks for sharing. Your addons and templates are much welcomed!

[kevincrafts]

Hmm good idea. Done.

[Dennis]

Kevin, I would love to see an option to set the size of the histogram (most notable because the 256 px is to wide for my template.)

[kevincrafts]

Dennis, I updated the addon so you can specify a width, but it still keeps the same dimension ratio.

[Dennis]

Ok that is pretty cool. Thanks :D

(Basically I was to lazy to do it :P)

[Dennis]

One more question: I might have overlooked it but is there a feature to make histograms for all the images based on a setting?

If not, this would be a cool feature to add because making histograms of 200+ pictures one by one kinda is a drag.

You've been quite busy making addons which we really appreciate.

[kevincrafts]

I could probably add a ""make a bunch at once" function but I'm not sure how many it would take before it timed out. Shouldn't be a problem though - let me look into it this weekend.

[kevincrafts]

There's a new version of the RGBHistogram addon which allows you to create histograms for a selected range of images - it is access through the addons page instead of the image edit menus.

Download (http://www.pixelpost.org/extend/addons/rgb-histogram/download/)

[iHamad]

i think you forgot to add the admin_RGBhistogram in the .rar file

[kevincrafts]

Ooops. Thanks for seeing that - it's updated now.

[iHamad]

:) thanks ..
now you added the mass RGBhistogram and forgot the old admin_RGBhistogram ..

unless you want to call it another addon as a mass RGB creator ..

[kevincrafts]

The previous addon file is not required. All creation/deletion is done from the addons page.

[Dennis]

Kevin, thanks a billion. Here is an insider tip: move the creation/deletion to a separate page. Don't misuse the addon list for it. We going to push towards making the addon list a real list with descriptions and nothing more. If I would have had my way, all <form> tags would be stripped from this list.

[kevincrafts]

The RGB Histogram addon is now it's own page/menu item - select range and create/delete histograms. Thanks for the suggestion Dennis.

[wjarosz]

Would it be possible to make the background of the histogram transparent? By either creating a PNG or GIF instead of the current JPG?

[wjarosz]

Hi Kevincrafts,
Great addon!

One comment: After adding it to my page I noticed that the combined color histograms didn't overlay the way I expected. For instance, I expected that where all 3 histograms overlap it should be visualized as grey or white, instead of the blueish color that the addon currently generates. After looking at the code, I modified it slightly to match the color scheme I expected. This also matches photoshop better. You can check it out on my photoblog (http://graphics.ucsd.edu/~wjarosz/photoblog/) and if you are interested in merging the changes back into your official addon I can make a diff available.

cheers,
-w

[kevincrafts]

Yes please - private message me the changes you made and I will add them.

[narky]

This a newb question. But I'm a bit concerned that I never quite got step three to work...? That is:
3. Add $lang_histogram = "<h2>Histogram</h2>"; to your language file.
Mainly because I wasn't sure if I was meant to put it in the admin file or the front end file (english in both cases in my instance). I did try placing it in a few different locations but upon saving the new language file pixelpost would refuse to load (regardless of the web address I used - admin or otherwise) I would just get a white screen. When I removed the changes (from the language file) everything would be okay again. In my latest attempt I ended up getting a button for the plugin (in the admin section where I had pasted the code - next to the logout button) and the plugin seems to be working. So, perhaps I have nothing to worry about...?

The result may be viewed at:
http://www.journal.narky.com.au

I quote the full list of instructions for clarity:
This addon will create a RGB Histogram for color images and a Luminosity Histogram for grayscale photos. Options include whether you want a combined/overlayed histogram (red, green, and blue channels overlayed on each other) or a stacked histogram (red, green, and blue channels separated) and the background color for the histogram. The histogram tends to be weighted towards the dark end on dark photos but the shape is still relatively the same compared to Photoshop.

Instructions:

1. Add admin_RGBhistogram to your addons directory.
2. Add histograms directory to your pixelpost directory and make it writable.
3. Add $lang_histogram = "<h2>Histogram</h2>"; to your language file.
4. Create histograms through the edit image menu by clicking on the RGB Histogram submenu (next to EDIT POST). Choose your background color and type and press the Create Histogram button.
5. Place <RGBHISTOGRAM> on your image_template.html file to display histogram.

See a Demo (http://blog.kevincrafts.com) - click on info & comments to see histogram

Download (http://www.pixelpost.org/extend/addons/rgb-histogram/download/)

[narky]

Oh, I forgot. Cheers to kevincrafts, a great gem of a plug-in!

[kevincrafts]

I added this to my lang-english.php file:

$lang_histogram = "<h2>Histogram</h2>";

All it does is put "Histogram" above the histogram image but it's not required.

[narky]

Well, i'm a silly one arn't I! Thanks for letting me know.

[kilkim]

Mass histogram creation does'nt work
I don't know why...

Only 2 histograms are created, the "start" one and the "finish" one but nothing between...

Does anyone have an idea ?

For instance :
Start : 201_xxx
Finish : 202_xxx
=> I have the message : "2 histograms have been created"

But
Start : 198_xxx
Finish : 200_xxx
=> no more message and after checking the histograms directory only the 198_xxx and the 200_xxx histograms were created.
No histogram for the 199_xxx

Where is my mistake ?

[kilkim]

Up ;-)

[Robbo]

Kilkim, I have found that it works best when I create the Historgrams singularly instead of more than one till now I have had no problems doing it that way.

[Kentin]

I've seen this question but with no replys, would it be possible to make the background of the histogram transparent? By either creating a PNG or GIF instead of the current JPG?

[kevincrafts]

Yeah it would be possible, but not something I have an interest in doing for the addon at this time.