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|Restoring & Preparing Plans Using Photoshop|
(screen captures removed)
Atlanta, Georgia, U.S.A.
After more than ten years and over four thousand five hundred plans prepared and restored in Photoshop I have developed a procedure that gives the best plans in the smallest file size. Many have asked that I help them learn how to do this so I have prepared written step-by-step directions covering the procedure.
These directions will cover:
I will be using Photoshop CS3 Extended, version10. For those of you using earlier or later versions of Photoshop the instructions should be the same with maybe an occasional change. My experience with Photoshop is that the basic functions we will call upon appear to exist in all but the maybe earliest versions. These instructions should also work for GIMP and GIMPSHOP, both free open source software available at
GIMPSHOP is essentially GIMP reworked to imitate the look and feel of Photoshop. I expect the outlined procedures can be accomplished in both programs, however the buttons and menus may be different.
For those of you that would like Photoshop, the latest version is around $675 (USD). There are a few who stoop to free pirated versions by downloading a peer-to-peer program like BitTorrent (http://www.bittorrent.com/), then going to a free proxy server (http://www.publicproxyservers.com/proxy/list_rating1.html) that contacts one of the pirate program websites (http://thepiratebay.org/) anonymously. They then search the pirate website for “Photoshop”. This is illegal and These people should be ashamed.
Scanning is straight forward and needs only a little description. As scanners and the accompanying scan programs vary, just follow their directions. Square up the copy (plan) as best you reasonably can on the scanner. If its a little crooked its O.K. All scans will be straightened up in Photoshop. Scan at a resolution of 300 DPI (dots per inch) in GRAYSCALE format. Many scanners call this “black and white photo”. Be sure to OVERLAP your scans by at least 1/4”. 1” or so is better as some scanners tend to have a little distortion out near the edges. With a little more overlap we can trim off the distortion.
I will put the selections to click on in Photoshop in PARENTHASES beginning with the File, Edit, Image, Layer, Select, Filter, View, Window selection at the top of the Photoshop screen. From there I will lead you step-by-step through the procedure. For example:
(Image – Mode – Grayscale) means locate the IMAGE menu at the very top of the Photoshop screen, click on it, then locate EDIT in the open menu column and click on it. When the little window opens select GRAYSCALE and click on it.
Errors can easily be fixed in Photoshop by backing up one or more steps and re-doing the procedure (Edit – Step Backward). Be aware that you can go back quite a number of steps but that number is limited.
I also strongly recommend that you save your work to file frequently. Computers seem to crash or the power goes out at the most inconvenient times.
OPENING SCANS AND PREPARING THEM FOR ASSEMBLY
We will open all of the scans for the plan in Photoshop. I assume you can do this without instruction. Then we will make a CANVAS (work area) that will be large enough to arrange all of your scans in rough order as they will be assembled with some extra room to shift them some.
Note that each scan will be on its own LAYER. Some people have a problem imagining this “layer” arrangement. Just read the Photoshop instructions about “layers” and keep at it until you get it. This is important.
Next we will straighten each scan so it is square with the screen. Once all of the scans are all straight we will trim the edges for a clean overlap. Then we will carefully connect each scan with the adjacent one with all of the plan lines precisely aligned.
At this point you will probably find one or more scans to be a very slight amount larger or smaller than the connecting scan. This isn't unusual as scanners aren't that precise. We will adjust the vertical and/or horizontal size of the scan a touch so the images will align perfectly. Even so, occasionally we will have to slightly shift individual pieces of the drawing a pixel or two or three to get everything to line up. Really, its not as hard as it appears. Don't quit now.
Once each scan is square to the screen, is in in position, and is accurately aligned with its adjacent scan, we will use the “FLATTEN” command to collapse the layers into one single layer making the various scans into a full plan all on one sheet.
Here we begin the step-by-step instructions to accomplish what I have described above:
A. First make a new blank layer (Layer – New – Layer)
B. Now using your Rectangular Marquee Tool at the very top left button in the Tools bar (Window – Tools) to make a long, thin horizontal box. Then fill the box with black (Edit – Fill – Black). You now have a horizontal straightedge on its own layer that you can use to bring all of your scans square to the screen.
C. Now select the scan you want to straighten by moving the mouse cursor over the selected scan, then right-click the mouse button and select the name of the layer and click on it. (Note: if you have multiple layers beneath the mouse cursor, the layers names shown will be in the order of the layers beneath the mouse cursor.) Double check that you have selected the correct layer by using your mouse cursor (left click on the mouse, hold button down) to move the layer a little bit. If it doesn't move, you need to re-select the layer.
D. Using the left mouse button and holding it down, drag the straightedge over atop the scan where there is a line on the plan that should be horizontal. I like to use the centerlines on plans wherever possible. Align one end of the straightedge with the centerline. If your scan is out of square it should show up here. You now need to rotate the entire scan until the centerline on the plan and the straightedge are aligned.
At this point I am going to explain the term “Focus” as it is used in Photoshop so I don't have to constantly explain it over and over. After this I will assume you understand this and the term “Focus” will be used without explanation. “ Focus” means the selection of the layer you want to work on. As each scan is on its own layer at this point, you must tell the computer whenever you shift from one layer to another which layer you want to use. We will be shifting back and forth from layer to layer as we work, or “changing Focus”. This is done by placing the mouse cursor over the position on the plan you wish to work on and right-click the mouse button. A little window will open up showing the names of the layers beneath the mouse cursor and their order. To select the layer you want to work on, left-click the mouse button on the layer name you want. You will have to do this every time you change layers.
E. Change the Focus to the scan to be straightened. We will now rotate the scan to align it with the straightedge by by the “rotate” command (Edit – Transform – Rotate). You will notice the scan now has a box around it with a small box at each corner and a small box at the mid-point of each side. At the exact center of the scan will be a very small bullseye-like circle. I will probably be difficult to find with all of the other lines on the plan but it will be there. This bullseye is the point of rotation and this point of rotation can be moved around. Use your mouse cursor to drag the bullseye around until it rests over where the straightedge and the plan centerline meet at one end of the straightedge. Now left-click and hold down the mouse cursor on one of the little corner boxes and drag the corner of the scan around until the plan centerline and the straightedge are aligned. Your scan should now be properly squared to the screen. Do this to each of the scans. To set the rotation permanent, just use your cursor to click on one of the top two tools on the tool bar. This will bring up a little window that asks if you want to apply the transformation. Click “yes”.
The plan I have selected to assemble and restore was scanned from a 1938 issue of Model Airplane news and was found on the Internet. Its resolution is less than I would prefer – 120 DPI (dots per inch) - however it was a relatively clean scan. Resolution is very important. It is the one thing you can rarely improve upon. This one looks like I can improve the plan and end up with a clear, crisp plan. We will see. Also, as is typical of the old magazine plans it is pieced together over multiple pages and there are no overlaps. For this reason I will use two adjacent scans from another plan to demonstrate how to match up two overlapping scans. Then we will return to this plan.
ASSEMBLING OVERLAPPING PLANS
As I mentioned above, this demonstration is from another plan, a peanut Fairey Fantome drawn by Pres Bruning. There are three overlapping scans that need to be joined. The scans have been squared to the screen
The screen capture below shows the three scans trimmed and ready for joining.
To make the join you need to find a point at the top of the scan where there will be an overlap of the adjacent scan that has a nice vertical and horizontal component to it – I look for a piece of type like an L, B, T, etc. or some fine point of the design. This gives you a target to align to. An example:
Now look for a similar point at the bottom of the scan.
Locate these same points on the matching scan you will join to and cut little pieces out so you can match this scan when it is layered over the opposing scan.
A. Do the “rotate” command (Edit, Transform, Rotate) as follows: When the rotate command bar appears at the top of the screen look for a little chain symbol and click on it. The “Chain” button makes the image retain its original aspect ratio. Then look at the adjacent scan image. There will be a square dotted line around the image. In the middle of this square will be a small “bull’s-eye” that denoted the center of rotation. Sometimes its hard to see, but its there. Slide your cursor over this bulls-eye and hold down the left mouse button while moving the bulls-eye over the top selected components that are matched, then let up. You have just moved the center of rotation over this point.
At this point we want to clean up all of the little blemishes on the plan – tiny black dots, fold lines from a folded plan, etc. We do this by forcing all of the white areas of a plan to a pure white and forcing all of the black areas of the plan to a pure black. This has to be done in stages to keep the details we want on the plan but remove most, if not all, of the blemishes. Each plan seems to have its own problems and we have to use various procedures to deal with them. When we finish, there are almost always some blemishes that can only be removed by hand-erasing what is left. A tedious task but a necessary one to have a nice result. As we will be dealing in shades of black, white, and gray, screen captures won't be of much help so I will omit these and only rely on verbal description.
There are various tools in Photoshop we use to do this and most are located in the Image- Adjustment menu. They are “Brightness/Contrast”, “Curves”, and “Posterize”. Note the “Curves” may require that you click on “Show All Menu Items” at the very bottom of the Image-Adjustment menu to view the “Curves” tool.
I have found that brightening the plan seems to work best with the “Use Legacy”box unchecked and the contrast usually works better with the “Use Legacy” box checked. This is not always the case however. You will have to try various combinations of brightness and contrast to get what you want which is to eliminate as many of the blemishes as possible without losing the details in the plan you want to keep. Each plan is a little different. When you get the plan as good as you can, move onto the next tool, the Curves tool (Image – Adjustment – Curves (or you may have to click on Show All Menu Items at the bottom of the Adjustment menu to see the Curves in some editions of Photoshop)
When the little “Posterize” window comes up, enter the number “2” and click on “O.K.”. This will make the grayscale image of the plans which has hundreds of tints of gray (from pure black to pure white) in it change to an image of only pure black and pure white. It does this by selecting any gray from 51% gray to pure black and forcing all of those gradations to pure black. It does the same for any gradations of gray from 50% gray to pure white, forcing those gradations to pure white. Re-read this last part again and understand what is happening. What you have done is drastically reduce the amount of information the file needs to save. All of those shades of gray are gone! This is the key to a small file size for the plan and it automatically cleans up most of those messy gray smudges in the plan. There will be a few black dots here and there left in the pure white background. Just erase those.
You can Posterize at 300 dpi and it seems to work fine for most plans. However if the “jaggies” appear in your black drawing lines, undo the Posterization and convert the drawing to a higher resolution – 900, 1,200 and up. If you go too high, Photoshop will tell you it can’t do it by offering you a smaller overall plan dimension. If this change in the plan dimension is not suitable, begin again using a smaller .dpi selection and keep reducing the .dpi until the .dpi selection works with the original plan dimension.
This is all I can tell you. You are on you own. Good luck!