lab 6: non-destructive editing in photoshop · adjustment layers modify airphotos using...
TRANSCRIPT
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Lab 6: Non-Destructive Editing in Photoshop
Prepared by Sarah Layton, Spring 2011
Prepared for Geog 467 “Applied Cartographic Design” with C. Brewer, Penn
State Geography
Introduction:
Non-destructive editing in Photoshop emphasizes basing maps on adjustment layers rather than
making edits to elevation data. It also utilizes the use of smart objects and smart filters to
preserve the original data of terrain data.
Outline:
Open Hillshade& DEM in Photoshop compatible format
Achieve realistic colors by blending in elevation through the use of masking into
adjustment layers
Modify airphotos using content-aware spot healing and other tools
Using smart objects and smart filters to edit non-destructively
Procedure:
A. Open DEM and Shaded Relief
Open your DEM and Shaded Relief in Photoshop CS5
The easiest option will likely be opening your TIFF files from Lab 1
Alex Tait example file: Katahdin.psd
B. Add color into the grayscale DEM (Hypso):
Under the Adjustments tab, apply a Gradiant Map above
the DEM (Hypso).
Click directly on the spectrum to open the Gradiant Editor
In the Presets window, choose a spectrum with any three
Non-Destructive Editing: Working with Terrain based on color adjustment layers
This technique for non-destructive editing uses color adjustment layers as the base of the
map to then blend the elevation into those solid color layers using them primarily as
masks. The elevation hillshade and DEM are left unchanged while the use of blended
color layers produces more realistic coloring.
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colors. Click directly on sliders at the bottom to adjust the colors. Set the Color to a
green, tan and light gray.
You can name and save a spectrum for later use by naming it and clicking New.
Back under the Layers tab, keep the blending mode at normal
C. Create Shadows:
Create a Solid Color Adjustment Layer with Dark blue
Now, apply the hillshade as a mask.
Activate the hillshade layer.
Use the Rectangular Marquee Tool on the left side to
select and Copy (Ctrl+C) the hillshade layer.
Use ALT +
Click to select the
mask (the white
square) on the dark blue
color layer. You should
see an empty white box.
You are now in the mask
channel. Paste in the
hillshade and Deselect (Ctrl + D).
How does a mask work?
Masks have the ability to only allow certain
elements of the layer to be visible. We will use
masks when we only want to apply a shade
to certain elevation values (using the DEM as
a mask) or to color shadows vs. illuminated
areas (using the hillshade as a mask).
IMPORTANT: Wherever the mask is black, none
of the image will be portrayed. Wherever the
image is white will be fully visible. The
grayscale values in between determine the
level of transparency.
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Now click on the MasksTab and click Invert. You should
notice that the dark and light values have been inverted.
You should now see the hillshade appears in the mask. The dark
blue is restricted to the shaded slopes. This is because the
grayscale mask values determine the opacity of the adjustment
layer throughout the image. The inverted black slopes do not let
any color through on the
illuminated side of the
terrain.
Now, choke the mask by
going to Image
Adjustments
Levels
Push the black slider to
the middle, and the
white slider in. This
brightens the whites and darkens the rest by restricting the range of dark values.
Back under the Layers tab, change the blending mode to Multiply for a more realistic
appearance
Set the Opacity of the layer to 40%
D. Create Highlights:
Create a Solid Color Adjustment Layer with Bright Yellow
Now, apply the hillshade as a mask.
Copy (Ctrl+C) the hillshade layer.
Use ALT + Click to select the mask (the white square) and Paste in the hillshade
and Deselect (Ctrl + D).
The bright yellow is now restricted to the illuminated slopes.
Now, choke the mask by going to Image Adjustments Levels
Back under the Layers tab, change the blending mode to Screen for a more realistic
appearance.
Important Tips:
Editing a mask is destructive. If you want to undo changes you have to “Undo” or start
over with
the mask. For complicating masks, make them as their own image and then copy and
paste them into the mask layers.
Blending modes for shading layers should be set multiply, while the highlight layers should
blend with Screen
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E. Create a Second Highlight Layer:
Create a Solid Color Adjustment Layer with White
Now, apply the hillshade as a mask.
Copy (Ctrl+C) the hillshade layer.
Use ALT + Click to select the mask (the white
square) and Paste in the hillshade and Deselect (Ctrl +
D).
The white is now restricted to the illuminated slopes.
Now, choke the mask even more than the yellow layer by
going to Image Adjustments Levels
Back under the Layers tab, change the blending mode to
Screen for a more realistic appearance
A. Pick-out the Forest: Add Color and Texture from a Land Cover Image
With the previous example, use a Solid Color Adjustment Layer in tan as the base
of the map
Open the practice: Katahdin_NLCD_Start.psd
On the land cover image, use the
Magic Wand (W) to click and select the
green pixels. Ctrl + C and copy the
selection.
Tolerance: 8 (or 16), Contiguous: off
Go back to the original image. Click CTRL + V
and it will paste the trees selection into a new layer
Note: For the sake of this example, the NLCD file
will not match up in size with your own Photoshop
workspace. If you want to download your own land
use file, you would need to go to the National Map.
ALT + CTRL + Click the layer to select all the
non-transparent pixels in the image, or copy the layer
using Ctrl + C.
Create a Solid Color Adjustment Layer with bright green
Paste the trees into the Mask, Deselect and Invert the selection under the Masks
Tab. Your mask should look all black with the white areas where the trees will go. Refer
back to part 1 for a more detailed masking process.
The Magic Wand Tool
The Magic Wand is a great tool
for quick selections. It allows you
to quickly find a particular color
anywhere within the image
based on the pixel value you
select. The tolerance determines
how small/large the range of
pixels values is that the tool will
select. When you select a pixel,
it will find the rest of the pixels
surrounding it (contiguous) or
from within the entire image
(non-contiguous)
Final Layers
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Double click on the adjustment layer so that the Layer Style dialogue box opens.
On the left side Check the box beside Bevel & Emboss.
Click on the name Bevel & Emboss to edit the properties. Adjust the angle to be
from the northwest to simulate realistic lighting. The greater the angle, the greater the
shadows.
Set the Blend to Multiply and Opacity at 20%
A. Making masks in a Remotely-Sensed Image
Open airphoto file: Chincoteague_start.psd
Using the Quick-Select tool (tolerance around 30), click and drag over the area of
water you want to select. Note: The Quick-select tool uses an edge matching algorithm
to find the layers of the image.
Add a Solid Color Adjustment Layer by clicking on the Adjustment Layer
icon at the bottom of the Layers Tab
When prompted to choose the color, click on the cube icon beside the color viewer.
When you move your cursor onto the screen you should see the eyedropper tool. Use
your eyedropper to select a water color from the image that you feel is characteristic of
most of it. When you add the color it should create an automatic mask of the selected
area, filled in with your chosen color
Non-Destructive Editing: Working with Airphotos
Note: Work at 100% Zoom so that you are seeing the actual pixels. When working at a
lower zoom, the pixel values are being averaged with other pixels close to it.
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Blend the layer with Multiply with the Opacity at 40%
Under the Masks Tab, choose Mask Edge. This will open the Refine Edge
dialogue box. In here you can refine the mask non-destructively to better smooth the
mask in.
Feather – softens the mask edge
Push out the edge – using shift edge
Note: For a good tutorial showing advanced masking techniques go to:
http://tv.adobe.com/watch/the-russell-brown-show/advanced-masking-with-
photoshop-cs5/
A quick mask
was created
when you
chose the solid
color layer.
Make sure your
mask is
selected in
order to choose
“Mask Edge”
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A. Smart Filters
Open: Roatan.psd
Right-click on the first layer and choose Convert To Smart Object.
You’ll notice the Smart Object
Icon now appears at the corner of the
layer icon.
Filter Artistic Fresco. This opens the filter dialogue. You can
now choose different filters, and add new filters. When you close the dialogue you will
see that the filter is on the layer and you can non-destructively edit and change the
visibility of each filter.
Non-Destructive Editing: Working with Smart Objects, Smart Filters and Other fun tools
Why as a smart object?
Photoshop deals with pixel-based images.
Typically, any edits applied to an image alter
the pixels themselves, thus losing the original
values. This is particularly problematic when it
comes to issues of scaling and transformations.
Smart objects embed a copy of the original
pixel values within the layer. By doing this,
every edit is made off of the original values
thus preserving the quality of the original
image. This allows for non-destructive editing,
and easier changes to filters and other layers.
Adjust which ones are
visible
Double-click on the filter on
the layer to open and
continue editing
Add new artistic filter
Why Smart Filters?
The ease of editing and turning filters
on/off makes smart filters preferable.
This is an alternative to creating a
separate layer like we did in Lab 4
Adjust which ones are
visible
Double-click on the filter on
the layer to open and
continue editing
Add new artistic filter
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B. Spot-Healing Tool
Create a new layer (since this is a destructive editing tool)
Open the Spot Healing Brush (Size: 20; Sample all layers – this will
base the selection on the pixels below it) – the healing happens on the new
layer and the base layer is untouched.
Click and drag to cover the area you want to remove. Best method is quick, short
strokes
C. Rubbersheeting with Liquify
Reload Roatan.psd
Duplicate the layer (because liquefy is destructive)
Filter Liquify – choose Show Mesh and put the Size to 100
Move coastline around. Why? You can use this to push rivers into position on old hand
rendered shaded relief where there is no actual projection attached to the image and you
want to rectify it with a georeferenced image. Need a big brush with a soft touch
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D. Rubbersheeting with Puppet Warp – non-destructive
Reload Roatan.psd
Duplicate layer
Convert to Smart Object
Edit Puppet Warp Creates a TIN
Apply pins to where you want to anchor your image (apply 6 along the
coastline)
Move Coast around
Editable! And this is good for old, hand shaded relief where there’s no projection to put
into it
E. Content-aware tools (new in CS 5)
Spot-Healing Brush with Content-Aware: get rid of Docks, boat wakes, etc.
Open: CLOUDS.psd again and zoom in on the dock
Add a new layer.
Select the Spot-Healing Brush. Make sure that Content Aware is on,
with a brush size of about 20. Choose sample all layers and paint on a new
layer so that it is non-destructive
Content-Aware Fill: use for clouds, lakes, etc.
With the Magic Wand or Quick-Select tool, choose the clouds
Click Edit Fill with content-aware ON
The history tab
allows you to
see what you’ve
done, and go
back to a
previous state
in the project
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Deliverables:
Two PDF files
One PDF of your Shaded Relief/DEM combination from Part 1, and another PDF using Alex
Tait’s Roatan.psd file that shows the use of smart objects, smart filters, and the removal of the
clouds and dock via content-aware tools. Place them in the dropbox named “Project 5: Sarah’s
Presentation” by March 30.
Sources:
Patterson, Tom, and Mike Hermann. “Value-enhanced Relief.” Shaded Relief. Web. 01 Mar.
2011. <http://www.shadedrelief.com/value/value.html>.
Patterson, Tom. “See the Light: How to Make Illuminated Shaded Relief in Photoshop 6.0.”
Shaded Relief. Web. 01 Mar. 2011.
<http://www.shadedrelief.com/illumination/index.html>.
“Photoshop Tutorials, How to Edit Pictures : Photoshop.com.” Photo Editing, Photo Sharing:
Photoshop.com. 2011. Web. 01 Mar. 2011 <http://www.photoshop.com/tutorials>.