2015-05-23

Free and Easy Photo Retouching

Blog Notice: I wrote this originally as a Google Doc and then pasted it to my blog. The formatting on this blog version is a bit off from the copy/paste differences. I'm putting it here to make it easier to find when searching Google. If you want to see the better-formatted version use this public Google Doc.

I wrote this for a friend who was new to image touch-ups. I’m making the document available to anyone who wants it. It was written for Gimp 2.8. Only a few items are here to get her started, I’m not covering Gimp in depth.  

Table of Contents:
1 through 4 … Initial Gimp downloading/installing/setup
5 and 6 … Opening the original image
7 … Cleaning up the Background
8 … Tuning the Levels / white balance
9 … Hints on making colors look more accurate
10 … Saving your image
Addendum … Comparing the results and an example of HDR Toning

  1. Install “Gimp” (GNU Image Manipulation Program … the free software world’s answer to Photoshop)

    … download it for Mac from http://download.gimp.org/pub/gimp/v2.8/osx/gimp-2.8.14.dmg
    NOTE: This is a direct link and will change as new versions come out. If this link has stopped working, click on the Windows/Linux link below and click on the “Show Other Downloads” link and look on that page for a link to a “.DMG” installer to find the Macintosh version.

    … download for Windows & Linux from http://www.gimp.org/downloads/

    NOTE: Your Mac must be running OSX version 10.6 (“Snow Leopard”) or newer. If you are not, I can find some alternatives but it might be a bit difficult. 10.6 came out in 2009. Anything from 10.6 through 10.10 will work.
  2. Copy the image to your Mac. You can do this any number of ways including email ing from your phone.

  1. Start Gimp
  2. You will want to make sure you see the Toolbox as it is the easiest way to find the most commonly used actions. It looks like this -->


    If you do not see this somewhere on your screen (Gimp uses multiple windows on most computers, the Toolbar will probably not be part of the main window but a second floating window), press Control+B (on Windows, if that doesn’t work on Mac, go to “Tools” and select “Toolbox” or “New Toolbox”).



  1. Open the image (you should be able to drag and drop it into the Gimp window or use the “File” / “Open” command).
    NOTE: For this tutorial I used this image (copyright 2015 Kay O’Neil, all rights reserved):


    When DONE with all steps in this document we will have:
  2. When opening the image, it may ask you if you want to convert the image to RGB. If so, click “Convert”. For web posting this is the best option anyway. If not asked, don’t worry about it.

    NOTES:
    1. I’m going to try and give keyboard shortcuts, but I use Gimp on Windows. If a keyboard shortcut doesn’t work and you can’t find the tool I am speaking of in the tool palette, just let me know which step didn’t work and I’ll write more details on how to find it.
    2. Don’t get frustrated. Any time you make a mistake you can easily undo it by pressing “Control+Z” or going to the “Edit” menu and choosing “Undo” at the top of the menu. You can undo multiple steps. If you go too far back you can “Redo” them with the “Edit” menu as well, just like a word processor.
    3. You may not need to do every step below for every image, this just gives a list of things to consider. Feel free to skip some steps if, for example, your background is already how you want it.

  1. Background Cleanup: (if you don’t care about cleaning up the background, skip all of the steps in this item and go to Levels, if you are careful with making sure your subject is on a clean background you often won’t need these steps)
    1. SIMPLE: If you want to remove the  background so that it is purely on white, there are a few things you can do:
      1. Click the Rectangle Select Tool (top-left of the Toolbox, looks like a dashed rectangle) and drag it around the parts of the image you want to KEEP like this (the dashed rectangle in the image below is from using the Rectangle Select Tool to draw the rectangle):


      2. CROP the image at this point to remove most of the area we want to get rid of by going to the “Image” menu and clicking “Crop to Selection” to get this:
      3. REMOVE THE SELECTION RECTANGLE by pressing Shift+Control+A or by using the “Select” menu and choosing “None”

    2. ADVANCED: If you have an image like this one that can’t be completely cropped, and don’t want to retake the photo (or can’t), you can remove the rest of the background with this process. It is more complicated than just cropping, but not extremely difficult once you’ve done it a time or two.
      1. Using the Rectangle Select Tool again (hashed rectangle in the Toolbox), select all of the background you can safely remove without affecting the subject of the image:


      2. Click the Clone Tool in the Toolbox or press “C”. It looks like a small rubber stamp. In the Toolbox it is in the left column 15 down from the top.

        The Clone Tool will allow you to copy one part of the image over another like a brush. The selection we made protects the rest of the image. To do this we need to tell the Clone tool which part to copy from.

        Until you have told it where to copy from the tool will show that it isn’t ready with this:

        1. To define the area to copy from … Press and HOLD the Control key and move the mouse slightly (keep holding the Control key). The disabled circle shown above should disappear and you see an empty circle like this:

        2. WHILE STILL HOLDING Control … click the spot shown below:

          NOTE: Click a very tiny bit to the LEFT of the Rectangle Selection (above the Rectangle Selection, as shown, but very slightly to the left). If you click too far to the right, you won’t have enough room in the copy area to cover the selection. You can do this over if you need to.

    1. Now that you have told Gimp where to Clone from, you can just paint over the background area to remove. Don’t try to fill the entire rectangle, just paint over the area we want to remove. (note: this is the simplest way to do it, there are better methods but they get progressively more complicated):
      Notes:
      1. There is still a small area on the left to deal with later, but you just repeat the process above after we’re done with this area
      2. Notice that the selection rectangle is still there. This prevents you from accidentally painting over the subject.

    2. See the area in the rectangle that looks a little different? We want to smooth that out using the Heal Tool … luckily it works much like the clone tool. Select the Heal Tool from the Toolbox or just press “H”.
      1. Like with the Clone Tool, we have to define an area for Gimp to use for healing. In this case you can click the exact same spot while holding the Control key that we used in the Clone Tool image above.
      2. Once you’ve clicked the anchor spot, use the mouse like a paintbrush and just go over the border line that you can see in the Rectangle Selection above. When done the image should look like this, which is good enough for this region.


    3. Repeat the above steps for the small area to the bottom-left of the subject. For a quick repeat of the process:
      1. Rectangle Select the area to remove (avoiding the shadowed area, which we will deal with in the final step for cleaning the background):

      2. Clone Tool (hold Control and click where the circle is shown):

      3. Use the Clone Tool (you don’t need to reselect it, you already chose it in the prior step) to paint over the background area:

      4. That actually matches up pretty well, but you can also go over it with the Heal Tool at this point to be sure. All done it will look like this:

    4. DELICATE: Now to get rid of the remaining portion that is couched in shadows from the subject. You aren’t going to get this perfectly as a beginning but it will be acceptable for now. The process is actually pretty simple.
      1. REMOVE THE SELECTION RECTANGLE by pressing Shift+Control+A or by using the “Select” menu and choosing “None”
      2. Clone Tool … control-click anywhere on the plain background area near the tail (we want to camouflage the rest of the bad background, but without more serious editing it won’t completely disappear, just be less noticeable). Then very carefully click the Clone tool so that the edge of the tool doesn’t go over the tail but does on the background on the bottom on either side of the tail. Done properly you will see this and we are ready to do color adjustment with Levels:

  1. Levels … this section will adjust the color levels of the image so that they look more vibrant. This section is VERY EASY and I would have preferred to do it first, but if you were going to fix the background the colors will adjust better if done after editing the background.
    1. If you have a selection made, REMOVE THE SELECTION RECTANGLE by pressing Shift+Control+A or by using the “Select” menu and choosing “None”
    2. Go to the “Colors” menu and select “Auto” -> “White Balance” and you’ll get this:

      Doing the Auto -> White Balance should be the same as doing:
      “Colors” -> “Levels” -> “Auto”

  2. OPTIONAL: There are many other ways to tune the image with the menus under “Colors”. It is up to you at this point to start figuring out what you feel is the most accurate image. Some things you can play with to adjust the image:

    1. Colors -> “Levels” … will allow you to fine tune the levels of light and dark in the image. Play with the various things in this menu to see what it can do, hit “Cancel” if you want to go back to the Auto White Balance (or just “Undo” with Control+Z if you OK it and don’t like it).

    2. Colors -> “Hue and Saturation”
      1. You can make washed-out colors more realistic by sliding “Saturation” a bit to the right. Be careful, just a little too much can make the image look cartoonish.
      2. You can brighten/darken the entire image while preserving color saturation by sliding “Lightness” a bit to the point where you like it.
      3. Mix and match the above until you hit the spot you like. You probably don’t want to bother with “Hue”.

  1. Don’t forget to save your image :) Use the “File” menu.
    1. To save it to a file that you can post on the web/Facebook, use “Export as” and save it as a JPEG (just end the name with “.jpg”), PNG (end the name with “.png”), etc or use the “Select File Type (By Extension)” (just click the + sign to open up the list) and select the format by hand. For most cases JPEG or PNG is going to be best. JPEG will be a bit smaller size for a photo like this, PNG will preserve more detail and is better for editing it again later.
    2. If you want to keep editing an image that has some extra things like layers and such (not covered in the above information), you can use “Save As” to save in the native Gimp format.


Addendum: Results:
This image used “Colors” -> “Auto” -> “White Balance” combined with “Colors” -> “Hue and Saturation” with Saturation bumped only to +5 and Lightness bumped up by +20:
 
Compared to the original
          

Addendum: HDR

The following image is a fake HDR image using Photoshop (not free) HDR Toning. A real HDR image would look more accurate and wouldn’t have the “glow” effect (unless you wanted it) but this gives you an idea of what an HDR photo might look like of the subject. Many cameras, even fairly inexpensive ones, can do limited HDR built-in. I’m not suggesting this is necessary, but it is something to consider. If you want to get very very complicated or install filters you could achieve the same with Gimp but it goes beyond the scope of this quick start. I’m just including it as I briefly discussed it with the person I wrote this document for.


Note: true HDR requires information that isn’t present in a single image, cameras that do HDR directly take a series of photographs at different exposures and merge them. You can also do this with a standard camera by taking multiple shots with high, normal and low exposures and merging them in Gimp or Photoshop. This takes a lot of time and based on the amount of effort it takes, if this is the type of photo you would like, I recommend looking at buying a camera with a good HDR function (many cameras do poor HDR). Some smart phones do HDR as well. However to get the truly rich HDR pictures you see on many photo sites, you need to do the merging in separate software to tune all of the details.