Restoring & Preparing Plans Using Photoshop

Download 63.47 Kb.
NameRestoring & Preparing Plans Using Photoshop
A typeDocumentation
  1   2
Restoring & Preparing Plans Using Photoshop

(screen captures removed)


Rufus Carswell

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:

  • Scanning

  • Assembly of multiple scans

  • Retouching and enhancement

  • File preparation

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 (, then going to a free proxy server ( that contacts one of the pirate program websites ( 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.


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:

  1. First of all, your scanner will scan all black and white images into Photoshop in “indexed color” mode (whatever this is). You cannot do much work in this mode so you must convert all of your plan scans to grayscale. (Image – Mode – Grayscale) Grayscale is simply a black and white image that includes all shades of gray in between.

  2. Prepare a “canvas” large enough for you to easily manipulate all of your scans by taking one of your scans and enlarging its “canvas”. (Image, Canvas Size) Now save this to a newly named file. I always save as a .TIF file.

  3. Drag all of your plan scans over into the large “canvas” and roughly arrange them in place. Be sure to leave each to its own layer.

  4. Next square each scan to the screen. To do this you must first make a “straightedge” to square to.

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”.

  1. Now that all of your scans are squared to the screen (and I assume your scans are overlapping the adjacent scan), trim the edges of each scan back some to get a clean edge with no white border but make sure you leave an overlap. To do this, Focus on one of the scans, then make a box with the Rectangular Marquee Tool from the Toolbox that is long or wide enough to make the trim, place the box over one of the scan edges in the proper position to make the trim, then hit the “Delete” key on your keyboard.

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.


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.

  1. Now slide this scan over the adjacent (left) scan and match the selected components of each scan at the top only. You will notice the bottom component may not match at this point.

    1. If the bottom point does not match up, click on the right scan to make sure the “Focus” is on that layer, then you proceed to rotate the right scan into alignment in the following manner.

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.

  1. Now move your cursor to one corner of the dotted square line or to an edge of the square line. Holding the left mouse button down, you can now rotate the entire right scan so the lower point can be brought into alignment.

  2. You may find the two lower selected components may not quite align correctly as one scan is ever so slightly larger or smaller than the other. Don’t’ worry, there is a fix. Just align them as best you can in the vertical or horizontal plane and let the other plane go for now.

  3. 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”.

  4. You now have your two overlapping scans exactly matching each other . . . unless you have your right scan a touch larger or smaller than the left scan. If that is the case, here is the fix.

  5. Making sure your “focus” is still on the right scan layer, select the “Scale” feature. (Edit, Transform, Scale). When the Scale features bar appears at the top of the screen, make sure the “chain” button is in the unlocked position, then zoom in on the lower selected components that have the miss-match problem. When zooming in, be sure to use ONLY your keyboard buttons (Ctrl + or Ctrl -) and not your mouse, or you will turn off the scale feature. If that happens, just bring it up again. Try to arrange it so the lower overlapping selected components and the lower dotted line of the “scale” feature are both visible on the screen. Now place the cursor on the lower dotted line and, while holding down the left mouse button, move the dotted line up or down ever so slightly until the selected components align in the vertical plane (you should have them already aligned in the horizontal plane when you did the rotation). When they are aligned, move the cursor over one of the two top tool buttons and click, thus bring up that little window asking if you want to apply the transformation. Click “yes”.

  6. Now you have the two scans in perfect alignment, but still on two different layers. If you have more scans to assemble, continue on using the same procedure. If you are finished, you need to collapse the layers into one layer (Layer, Flatten Image). Its wise to do a save” at this point.

  7. Now that your plan is assembled, you need to do a final straightening to get it square with the screen. (1) Make a straightedge. - To rotate a component or an entire drawing to be square with the screen, make a straightedge to place next to the part to be rotated. Move your “focus” to the background and select a nice white area with some room. Use the Rectangular Marquee Tool to shape a long, thin horizontal (or vertical) rectangle. When you have the shape you want, click on (Edit, Fill). A window will come up. Tell it to use the foreground color (black) and click “O.K.”. You now have a nice thin black rectangle with a dotted line around it showing it is highlighted. Now click on (Edit, Cut), then (Edit, Paste). That black rectangle in now on its own layer. You can slide it anywhere you want to use as an aligning tool.

  8. To rotate the plan, change the “Focus” to the plan layer (Mouse right-click – select Background). Use the Rectangular Marquee Tool to outline a box around the entire plan to indicate what is to be rotated. Use the “Rotate” feature as described before. You can also type in the degree of rotation if you want in one of the little windows of the “Rotation” tool bar. Or – you can use the “Rotate Canvas” feature (Image, Rotate Canvas). When finished with the Rotate. I advise saving the file at this point. When the plan is square to the screen you can proceed to do some basic clean up of ­the white background of the plan using the Eraser tool on the toolbar.

  9. Dropping backgrounds

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.

  1. We begin with the “Brightness/Contrast” tool ( Image – Adjustment - Brightness/Contrast). You will note when this tool is used there is a little box at the lower right corner of the Brightness/Contrast window that says “Use Legacy”. This is a more drastic method of brightness/contrast than the normal brightness/contrast. Bring up the Brightness/Contrast tool ( Image – Adjustment – Brightness/Contrast) and play around with the slider bars while watching what happens to the plan to get an idea of what this tool does. When you are finished, re-set the bars to zero.

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)

  1. Open 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). Slide the little slider bars around that are on the outside edges of the box and observe the plan to see what happens. This is about the only way to describe this tool. What I use it for on plans is to darken the lines of the plans. You will just have to play with it to see what it can and can't do. When you have – or have not – used this tool, proceed to the Posterize tool.

  2. At the top of the Photoshop screen click on “Image”, then “Adjustments”, then “Posterize”(at the bottom). Posterize is an old photographic process of reducing the number of gradations of color to only a few. It makes an interesting effect. What you will do with the Posterize tool is do a final reduction of all grayscale tones to only two colors – a pure black and a pure white. Pure black for all plan lines, pure white for the background. No shades of gray in between!

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.

  1. Now that we have reduced the plan to nothing but pure blacks and whites, we want to employ a file type called “50% Threshhold Bitmap to remove all unneeded file information to reduce the file size. This reduces the file size considerably without degrading the image quality if done correctly. Look at the size of you file before and after this process to see how much. You'll be surprised!

  2. Convert the posterized grayscale image to a 50% Threshhold bitmap (Image, Mode, Bitmap). Note: in some versions of Photoshop you will have to click on the “Show All Menu Items” in the Mode menu to see the Bitmap choice. A window will come up. Under “Method” select “50% Threshold” and check the pixel output above to make sure it hasn’t shifted. Click O.K. Like posterization, this also forces all shades of gray below 50% to 100% white and all shades of gray above 50% to 100% black. In fact , this was the way I first “posterized” before I figured out the other posterization procedure which seems to do a better job of reducing the “jaggies”. This greatly reduces the amount of information the file needs to retain and allows for much reduced files sizes – like 1/10th or more. To see how much disk space is saved look at the file size of the before and after. You will be impressed.

  1. 4. Final touch-up. - you may find some lines weak or broken after completing your plans conversion to this point. If you want, you can touch these up by using the “line tool” to trace over these weak or broken lines. To do this, look for the line tool on your Tool Bar just below the big “T” (for “type”). It may not show as a line tool as other tools are represented here too (rectangle tool, ellipse tool, polygon tool, etc.) but click here and look on the little window that comes up for the line tool and select it. When the line tool is selected, look at the options bar at the top of the screen for the “weight” option. Use this to adjust the width of the line in pixels. (Remember that as the resolution is increased the number of pixels needed for the same width of line increases proportionally.) Try the line tool on your drawing to see if the weight of the line is what you want. If not, just use the ”undo” or “step backward” option (Edit, Undo or Step Backwards) to remove it and adjust the line width and try again. You’ll get the hang if it. One thing to note. When working in bitmap mode there are no layers so your line will be drawing directly over the weak line on the drawing. If you find this to be a problem, you may want to temporarily change modes back to grayscale so you have the use of layers. By doing this you can draw your line over the top of the weak or broken line of the drawing and then change layers from the line layer to the drawing layer and erase the weak or broken line that is beneath the line you drew. You can then flatten the layers and have a very clean new line. When you are finished convert your drawing back to Bitmap (50% Threshold) mode and save.

  2. Once we have completed the Bitmap conversion we want to save our final file as an Adobe Acrobat file. Adobe Acrobat converts the bitmap file to a vector image file. Vector files describe the image as mathematical calculations (“Vectors) rather than bitmaps (little dots). This further smooths the line of your drawings and enables the drawing to be enlarged or reduced using other programs like Photoshop without loosing resolution. This means you can later open your Adobe Acrobat .PDF file in Photoshop, choose the resolution, and convert it back into a grayscale file for enlargement of reduction in size.

  3. Use Adobe Acrobat or an equivalent program like PDF Creator (Windows only), a FREE program which can be downloaded at Open the bitmap plan file in this program and save it as a .PDF file. It is really this simple. This further compresses the file and saves file space. I find that a 30 inch by 40 inch size plan in high resolution saved using the procedures outlined here can usually be around one megabyte or less. This obviously uses less disk space and facilitates e-mailing plans as attached files.

This is all I can tell you. You are on you own. Good luck!
  1   2

Share in:


Restoring & Preparing Plans Using Photoshop iconAn insight into owning, restoring, servicing and flying Britain’s classic World War II fighter

Restoring & Preparing Plans Using Photoshop iconFeatures in Adobe Photoshop cs6

Restoring & Preparing Plans Using Photoshop iconAdobe® Photoshop® cs6: Part 1

Restoring & Preparing Plans Using Photoshop iconAdobe® Photoshop® cs6: Part 2

Restoring & Preparing Plans Using Photoshop iconLearn About Adobe Photoshop cs6

Restoring & Preparing Plans Using Photoshop iconChapter 1 Getting Started with Adobe Photoshop cs5

Restoring & Preparing Plans Using Photoshop iconNo Color Management option missing | Printing | Photoshop cs5 Products affected

Restoring & Preparing Plans Using Photoshop iconActiveX, com/dcom, Flash mx, Photoshop, Illustrator10, Fireworks...

Restoring & Preparing Plans Using Photoshop icon1. Preparing the Input File

Restoring & Preparing Plans Using Photoshop iconGuidelines for Preparing Manuscripts

Restoring & Preparing Plans Using Photoshop iconTest Plans

Restoring & Preparing Plans Using Photoshop iconLesson Plans 19

Restoring & Preparing Plans Using Photoshop iconUser Plans 2-4

Restoring & Preparing Plans Using Photoshop iconAbstract-These instructions give you guidelines for preparing papers for

Restoring & Preparing Plans Using Photoshop iconGuidelines for Preparing a position paper for your Philosophy of Education

Restoring & Preparing Plans Using Photoshop iconAbstract -these instructions give you guidelines for preparing papers for the

Restoring & Preparing Plans Using Photoshop iconProfile 1 Existing Plans

Restoring & Preparing Plans Using Photoshop iconPreparing your Trimble GeoExplorer ce series gps unit (GeoXM) for use

Restoring & Preparing Plans Using Photoshop iconPreparing for the Future of Brunei Darussalam: Selected Scenario Analysis

Restoring & Preparing Plans Using Photoshop iconSchedule of Prices B. Construction plans


When copying material provide a link © 2017