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Picture Enhancement Tutorial

Discussion in 'Darkroom Tutorials' started by PapaBob, Feb 19, 2005.

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  1. PapaBob

    PapaBob ScubaBoard Supporter ScubaBoard Supporter

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    This tutorial is an extension of the discussion in This Thread

    Adjusting a picture subject using a separate layer
    Making a selection of the subject in Quickmask mode
    Converting the selection into a layer mask.

    INTRODUCTION

    Before I get into this tutorial, some introductory comments. This tutorial is of very limited use to someone using Photoshop Elements. You should have PS7 or PSCS and some experience with the basic tools. I encourage questions from PSE users and hope to write some tutorials directed at the PSE crowd.

    I am a BIG believer in the Quick and Easy school of photo manipulation, especially if I am processing a lot of photos at one time. Load em in, make the fastest and best adjustments you can and save em to a file. When I open an image (after raw conversion if it is a raw shot), I immediately copy it (Image>Duplicate) and work on the copy. This does not take any time at all and lets me go back to the original if I need to. In the copy I start my work on a duplicate background layer (Control-J gets you there real quick). I can always trash the layer and make another copy of the background layer if I need to.

    If you have muddled through my article Overall Color Correction of Underwater Images in Photoshop then you know I believe in making the big adjustments (overall color correction) first. I have created some actions Bob's Automatic Actions to try to speed this process, but often manual adjustments work better and give a finer result.

    After you complete the overall color correction, there is usually a part of the image (subject) that did not turn out the way you wanted. Maybe the background water is no longer a natural color even though the fish and sand look natural. Gee, you got the reef looking good but the fish and the sand didn’t respond. Every image will be different.

    In my shark picture posted above, I didn’t like the shark, didn’t like the color of the water, didn’t like the cyan cast in the sand, and didn’t like the appearance of the diver (me!). No one adjustment, no matter how cleverly crafted, is going to fix all of that.

    The first question you have to ask: “Is it worth the time and effort to rework the photo?” I answered yes because this is one of the few pictures I have which was shot by a friend and I appear in the photo. Otherwise, it was probably not worth the effort I put into it.

    Back to Quick and Easy. Yoda has a great idea. Fiddle with the photo and if you don’t like the results, then back up a few steps in the History Palette and try again. I cannot tell you how many times I have used this method. As my article suggests, History Snapshots allow you to experiment, take a snapshot, go back to the start and try something else. Quick and Easy. You can return to any snapshot and work from there, compare snapshots, and pick the result you like the best to save.

    There are two problems with the Q&E History Palette approach. First, after you save and close the file, all history states are lost, including all of your lovely snapshots. Second, isolating multiple subjects in the picture and combining them is possible with the history brush feature, but not the best method. Using multiple layers for each subject and isolating the subject from the rest of the layer using a layer mask .is the way go. If the adjustment of each subject is made on a separate layer, then you can save a psd file and go back and redo the layer at a later date.

    Layer sets (more advanced Photoshop now) let you combine various layers and work them together rather than separately. Think of it a layer with sublayers. For example, I worked the shark on 5 different layers which I combined as the “Shark Set”. This allows me to go back and tweak any one of the 5 shark layer adjustments without affecting the others. I can then apply adjustments (or a mask) to the entire set without individually adjusting each of the layers in the set. I could have done the work on a single “Shark Layer”. For the purpose of this exercise, I want you to think of the Shark Set as if it were just a single layer.

    OK, back again to Q&E. Lets say I open a new image and do my overall color correction. Everything looks great except the shark. I can select the shark and do separate adjustments on it without all this layers business. When you make an adjustment and there is an active selection (note the “marching ants” on the screen) then the adjustment will only apply to what you have selected and leave the rest of the image alone. This is great for Q&E adjustments and I use it all the time. Problem is that the selection may not be perfect or feathered (blended) properly and now that shark will stand out. The appearance is usually an obvious “cut out” or a “halo” or as Mike calls them “the crappies”. Sure you can go back and redo your selection, but after a few attempts the process can get frustrating. If you make your adjustment on a separate layer, and use your selection to create a mask, then you can adjust the shark and the selection separately by adjusting the mask.

    On to Part I.
     
  2. PapaBob

    PapaBob ScubaBoard Supporter ScubaBoard Supporter

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    If you want to try this out, then print out the tutorial and download my original shark pic at the top of this thread. Make sure your Layers Palette is open in your work area. In a duplicate image make two layer copies of the background (hit Control-J twice). With the top layer active make any adjustments you want to improve the shark. Don’t worry about how the rest of the image appears to be affected, but it should look different than the original so the effect of isolating the shark will be apparent.. We are going to block out all of the top layer except the shark with a mask. First we have to select the shark.

    There are tons of ways to make a selection, and a lot of ink has been spilt on this subject alone. I like to paint selections with the quickmask where there is not a sharply defined or straight border or clear color contrast where the magnetic lasso or magic wand tools might be effective (read most underwater shots). Here is a screenshot of my quickmask of the shark.

    [​IMG]

    First select a brush. I used a 20 pixel brush and hardness of 30% (fairly soft) for this.

    Type the letter “d” to set the default foreground and background colors in the toolbar as black and white. Black will paint the mask and white will erase what you painted. You can toggle between the two by pressing the keyboard letter “x” (think eXchange) or clicking on the toggle icon in the toolbar.

    Don’t paint yet! If you do you will paint black or white on your image. Make sure the top layer is active and click on the Quickmask button in the toolbox (right button third from the bottom). Now when you paint with black you will get a red 50% opacity overlay showing the areas you have masked. Paint with white and the red vanishes. You can actually see your selection much better with this method when compared to the “marching ants” which result from other selection techniques..

    I paint the borders first with a smaller brush to get the detail. I use the navigator (or zoom function) to zoom in on my selection. If I over paint the border, I can toggle to white and erase back. If I didn’t get enough shark then I can fine tune by painting more with the foreground color set to black. I can adjust the brush hardness to get the edge definition I want. You will get the hang of it with a little practice.

    Often you need to adjust the brush size, smaller to pick up finer details and larger to cover more area. The “]” key makes the brush bigger and the “[“ key makes the brush smaller.

    Once I have a nice border, I make a bigger brush and paint in the rest of the mask with black as the foreground color to get the red mask overlay. Then I go back into navigator and zoom in to check the borders to make sure I painted the nice fine selection I was looking for. This is not Q&E but the result is worth the effort. Besides, I find the “painting in” to be good relaxation therapy. You might prefer knitting. OK diving IS the best but we can’t dive all day every day...can we?

    Next to Part II
     
  3. PapaBob

    PapaBob ScubaBoard Supporter ScubaBoard Supporter

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    The objective is to create a mask for the shark layer which will allow the shark to shine through but the rest of the shark layer to be blocked out revealing the next layer down. The following screen shot shows how this is done.

    [​IMG]

    First, click on the quickmask convert button (third up from the bottom on the left hand side). This converts the quickmask into a selection. Initially you will get the “marching ants” around the shark but also around the border of the image. Remember, you have “masked” the shark so what you have “selected” is everything but the shark.

    To select the shark choose Select>Inverse. Now the marching ants will just march around the shark (and not the border). You have selected the shark and masked the background. Want to check? Click on the quickmask button and the background will be red and the shark will be normal. Just be sure to click back on the selection button to get the selection ants marching around the shark again.

    Next, open the Layers palette (if it is not already open in your work area). Make the shark layer active. Then click on the mask button (second from left at the bottom of the layers palette). A mask thumbnail will appear to the right of the image thumbnail in the layer you are working on in the Layers Palette. Note that the background in the mask thumbnail is rendered in black and the outline of the shark is rendered in white. This means that the black part of the mask is blocking that part of the image from showing and the white is allowing only the shark to appear. Any adjustments you did to that layer will only show on the shark. The black part the mask blocks the rest of the image and lets the next visible layer down show through for everything but the shark. If that layer has a great background then the good shark (top layer) will appear with the good background (next visible layer down).

    On to the finale - Part III
     
  4. PapaBob

    PapaBob ScubaBoard Supporter ScubaBoard Supporter

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    In my adjustments I used 4 layers (sets). The top layer was the shark layer where I just made adjustments to improve the shark and let the shark shine through with a layer mask made from my quickmask selection discussed above.

    The next layer down was the diver layer (me!). I used the same technique to make me look better in a separate layer (set) and used quickmask to just let me shine through.

    The third layer from the top was the background (water). The layer mask allowed only my adjustments on that layer to appear in the final image

    The bottom layer was the sand (foreground set). I didn’t have to mask that layer because it was the bottom visible layer I was using

    The original background layer at the bottom it is blocked out by all of the layers above it and is not visible. I keep it to make additional layer copies for further work if I need them.

    The following screenie shows the layers palette on the left.

    [​IMG] ***

    Tip1: When using multiple layers and masks put the closest object (shark) in the top layer. The next closest (diver) goes in the second from the top. In the water (background) and sand (foreground) layers, the order did not matter.

    Tip2: When you turn a selection into a mask, it Photoshop automatically creates an alpha channel from the selection. See the Channels Palette above. When that layer is active you can turn the alpha channel back into a selection by clicking the selection button at the bottom left of the Channels Palette.

    Tip3: Lets say you don’t like the mask (oops a crappy slipped in there). Go to the layer that has the mask and click on the mask thumbnail to make the mask active for work. You can now paint with black to mask more or with white to unmask. If black or white “paint” is actually appearing in your image then you have your layer active, not the layer mask. Undo, click on the mask thumbnail in the active layer, and start over.

    Tip4: If you want to see your mask in black and white on the big screen, then Alt-click on the mask thumbnail. You can work directly on the black and white mask if you want to clean it up. To go back click on the image thumbnail in the active layer in the Layers Palette.

    Tip5: If the selection is too sharp (hard edged) and you want to blend it in with the other layers more smoothly, then click on the mask thumbnail in the active layer and choose Filter>Blur>Guassian Blur. Start at 0 and move the slider to the right to improve the “blend”. Watch the edges of your subject soften. I like to work with a softer brush. Some authors suggest using a hard brush and if the subject looks too “cut out” then the edges of the subject can be softened using this method.

    Tip6: If you don’t like to paint, then make you selection using the lasso, magic wand, Select>Color Range, pen tool (ugh, I still don’t know how to use this tool) or marquee. Convert your selection into a Quickmask by hitting the Quickmask button. Note, your subject is clear and the mask (red) applies to the image other than the subject. You can now do your fine tuning in Quickmask mode, hit the selection button, and create the mask on the active layer in the Layers Palette discussed above.

    That is it for this tutorial. Play with it for a while and if you need help with any of the steps, let me know.
     
  5. Dee

    Dee ScubaBoard Supporter ScubaBoard Supporter

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    Excellent tutorial, Bob! The screen shots and tips make it so much easier to understand. Thanks for taking the time to put it all together. :thumb:
     
  6. hawk2

    hawk2 Angel Fish

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    yea that was good
     
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