A little fun in RGB and Curves

I love puzzles, love figuring things out.  Recently I tried out two 'tests' that were posted on Facebook.

The first one tests your knowledge of curves.  The creator of the test provides a quick (I would have liked a little more information) explanation on each answer.

Understanding how curves works, whether in Photoshop or Lightroom, helps to create colour manipulations with just a few adjustments.  You are able to work independently on the red, green and blue channels (RGB - Red, Green, Blue) and the slightest shift on the curve can dramatically change the photo.

The first link here is the Curves Challenge.  The second link is each part of the challenge discussed lightly.

Curves Challenge
Curves Challenge Explained

Now the reason I posted the Curves Challenge first is because it can help you understand how RGB works i.e. moving one curve up lightens the colour, moving it down darkens and this also works as an add and subtract equation.

The more you lower the curve below the grey/gray line the more you remove the colour.

The second quiz is a little more difficult.  Here you are working with numbers, each number corresponds with the amount of red, green and blue that has been added or removed from the photo.

The first number is red, the second green and the third blue.  I'm not going to give it away and even though this is not an absolute necessity in photography it will help you understand colour a bit better.  And hey, it's fun once you get the hang of it.

Think about adding and subtracting, the higher the number the lighter the colour, the lower the number the darker the colour.  Also think about how colours work together i.e. if you mix green and red you get yellow etc.

I found that working out the first two and then adding the third is how I was able to figure out the closest answer.

RGB Challenge

Once you have an idea of this all fits together it should open your eyes to the bigger world of colour.

But...if you want to be able to test out your colour theories and practice try this Colour Chart.

Digital Restoration of Photos - fading, rips, water damage etc

Sorry that I haven't been active on my blog lately but time has kinda gone AWOL on me.  I recently found out about an organisation called Operation Photo Rescue.  They have created a data base of people who have volunteered their skills in restoration of photos for victims of natural disasters.  In order to become a volunteer you need to fill in and submit a form and also restore a test photo that is sent to you.  I passed the test (big smile) and am now a volunteer.

The point of this posting is to discuss restoration of photos.  When I first started, which wasn't even 2 years ago, I tried my hand at restoring a photo nearly 100 years old as well as a photo with missing pieces.

After some searching for tutorials I can see a few places in the second one that needs work.  But still, not too bad for a beginner.

I have since searched further but honestly can't find a large amount of info on the Internet.  I have also looked at books but have found only one that's ok (not great, but ok) that also includes Photoshop Elements.  Other books lean more towards CS (the above images were restored using PSE9).  I think people tend to undervalue PSE and its abilities for restoration.

When it comes to books I personally don't want to have pages and pages of what storage systems to use, expensive software and so on.  I actually just want a book with tutorials.  But some people do prefer the added info on what to use.  

Digital Restoration

Anyway, I did find some sites with info:

http://www.cambridgeincolour.com/tutorials/digital-photo-restoration.htm

http://www.hp.com/united-states/consumer/digital_photography/edit_restore_photos/tips/restore_photos.html

https://familysearch.org/techtips/2011/07/beginning-digitization-principles-restoring-old-photographs

http://www.scantips.com/restore.html

I haven't been able to find techniques per say and many of the sites are service based i.e. offering the service of restoration.  I will discuss below what I use and what I have recently learned.

As restoration also depends on colour correction (the first thing you should do before restoring I'm told) you will need to use Curves and Channels as well as Levels.  Curves and Channels are not found in PSE (Levels is found in PSE).  But....Elements + does have both features (an inexpensive add on that opens up hidden features of PSE).  

Colour channels like Blue are used to bring out hidden details in a photo that might otherwise be hidden by water damage, mould etc.  It's still something I have to try out but here is a site about creating individual channels: http://www.photokaboom.com/photography/learn/Photoshop_Elements/layers/separate_RGB_channel_layers/1_separate_RGB_channel_layers_introduction.htm

Levels is also a very important feature that works with exposure and contrast..  Be careful about clipping or losing information.  http://www.photokaboom.com/photography/learn/Photoshop_Elements/workflow/first_steps_10/11_workflow_first_steps_10_Levels.htm

Remember to use adjustment layers instead of directly using the features on the photo as adjustment layers are less destructive and can be removed at any time without disrupting the pixels.

Typically I use the Clone Stamp and Healing brush although more the Clone Stamp as the Healing brush can give undesired results.  If the area I'm working on has missing information or very little information I then work at about 200% zoom or more.  Using the Clone Stamp I work on what information (area undamaged) there is and start cloning back little at a time.  Once I have a big enough area that is undamaged I increase my Clone Stamp to fix the damage quicker.

Keep in mind, the Clone Stamp just clones the areas so sometimes I go over an area again to give it a different texture so a pattern isn't repeated e.g. highlights in hair with the same width, shape etc.  Also, be careful about using cloned areas that have less detail than the surrounding areas where the damage is.

REMEMBER to save your file (PSD is best, you can always create a JPEG separately when you are done) around every 5 or so minutes.  The electricity can fail, a storm can hit, your computer may decide it's had enough and just switch off on it's own.  SAVE SAVE SAVE.

Since every photo is different, there isn't a set method to use.  But if you learn the basics then all you need is patience and some observation.  Photos with missing or damaged areas can still provide enough clues as to what is missing or damaged,  Pay attention to shadows and shapes.

I'm still learning and searching.  If you come across any sites with tips and techniques please share :-D.

Have fun!

Update: I've have since been reading Digital Restoration from Start to Finish by Ctein and it's an incredibly in depth book.  I would definitely recommend it for anyone interested in Restoration of Digital photos.