Options for getting large patterns digitized?

[JoeRees]

I need a way to vectorize large paper tracings in a 1:1 scale so that when I plot them out they match the original hand-tracing very closely. I'm talking about originals that are up to 3' x 4'. I'm thinking that a large digitizer tablet or oversized flatbed scanner would be a good tool for the job but who has these anymore? I can attest that trying to draw over a photo of the original with CorelDRAW's freehand tool is not practical because of inherent distortions in a cellphone pic - no matter how perfectly you follow the pic the resulting vector paths never really matches the original tracing, resulting in a seemingly endless spiral of editing and re-plotting to check improvements...I eventually get there but holy-moley what a clunky and wasteful process. Wasteful because I don't have a pen-drawing plotter and must cut vinyl for each test plot. There's got to be a better way. How would you handle a task like this or do you know of a service who can scan my patterns full scale?
Thanks,
-Joe-

 

[Andy D]

Most print shop that provides "blue print" services has large scanners. Our scanner kind of looks like a plotter, you load the print on one side
and it runs it through, so it can be 3' x whatever length.

 

[2B]

try contacting a CAD printer, they regularly convert construction drawings to digital

 

[Gene@mpls]

The key is taking the picture square to the drawing and moving farther away from it, as long as you can zoom in before you trace it. And then plot it on paper instead of cutting it.

 

[sardocs]

Is there no way to fit a pen to your plotter? Our plotter wasn't designed for pens but we regularly fit a ballpoint or a sharpie on the carriage for exactly this purpose.

 

[Andy D]

Advice I have gotten from this site from other members about taking images with little to no distortion is to:
make sure you are square and level with the subject, back up to where the details you need are still visible, don't zoom in, set your camera to the highest dpi/ppi,
make sure the lines are what the camera is focusing on & take the pic.

 

[James Burke]

Tape it to the wall, set your camera on a tripod, snap a photo, trace off the photo.

The arcs in your drawings could be traced very easily with AutoCAD.

With AutoCAD's "start, end, direction" arc function, you simply click on an arc's start point and end point, and then drag the curve so it matches your pattern. Easy peasy...and really fast.

JB

 

[shoresigns]

match the original hand-tracing very closely

If that's the case, ignore all the advice you're getting about cameras and find someone with a large scanner. Unless someone here knows how to perfectly compensate for all the different types of distortion that a camera introduces.

 

[Jester1167]

I see you used the words "very closely match" and I see that the original is black and white. Unless it's on a curve I would have taken a picture, traced it, scaled it, pen plotted it, make any minor adjustments, and then cut it. That would be very close in a lot less time then the hand tracing and then finding someone to scan it $, and you still have to vectorize it.

Even if it is on a curve, taking a picture of what you have now will be cheaper and faster and match "very closely.

Lens distortion is almost nonexistent even on your cell phone if you keep the image in the center 1/3 of pic and you shoot straight on. Don't use the wide-angle lens if you have one.

Below shows the lens distortion on my Galaxy S10+. 8.5 x 11" with a .5" grid and none of the images were cropped.
Order of images Zoom, Normal, Wide Angle

 

[woolly]

been trying to justify a roll scanner but still use a camera if really critical normally draw a known size box around the drawing to help trap any errors.
one tip i would draw one vector through the centre of the lines then add a pen width to suit. then convert pen width to outline so end up with parallel vectors.
if a pen a dot shape is used it will give you the rounded ends

 

[McDonald Signs]

I have a tile floor in my shop made up of square tiles and grout lines. I lay the paper pattern on the floor and get right above the pattern on a small step ladder, square up the lens in my Iphone with the grout lines in the
tile floor in all sides of the lens and snap a photo. Then email the photo to my computer, import to my drawing program and size the pattern full size in my program and trace it on screen.
Works pretty well for me, we do alot of vehicle decals this way.....

 

[Bobby H]

The key is taking the picture square to the drawing and moving farther away from it, as long as you can zoom in before you trace it. And then plot it on paper instead of cutting it.

That approach can only, at best, get in the ballpark in terms of accuracy.

First of all, mobile phone cameras only stink when it comes to tasks like zoom. Mobile phones have fake zoom, not an actual optical-based zoom lens. They crop into the image and then blow up the cropped result. Lousy.

A real camera with a real zoom lens, mounted to a tripod, will do far better. But even the results there get only so good. Perspective is always a distorting issue, no matter how far back someone positions the camera and zooms into the image. There's always some form of barrel distortion.

Here's an idea. The approach won't be fun. But if executed properly the scanned results will be dead-on accurate. Take that pattern, or a traced copy it, and break it up into tiles small enough to fit in your scanner. Carefully draw a grid of squares across the whole thing, as well as some diagonal lines for extra aid in registration. Then cut all the squares apart and scan each square tile. You should be able to piece together the images in Photoshop or any other decent pixel-based image editor. The end result won't have any of the barrel distortion perspective fall-out that is always present in photographs. Every tile will be 1:1 accurate. You just have to fine-tune how all the tiles join together. It's a painstaking process just getting every tile oriented consistently in the scanner to minimize fine-tuning and editing on the back end.

This approach isn't much different than the old scale grid approach used by mural painters.

 

[Greg Kelm]

Best DIY I’ve found is to cut it up into manageable pieces, scan and stitch the files back together in photoshop/illustrator.

 

[Gino]

I have no idea if this was said already, but if you don't have access to the correct tools or the original template....

• Take a picture with no zoom at a distance where you get the whole thing in your field of vision
• Next if you don't have a pen plotter, then print it out at about 25% of the original size
• Put it under a light table and trace onto some paper
• It looks like a buncha french curves and whatnot, so use those tools (which any sign shop has on hand) and recreat it at a reduced size
• Now, scan it in at this reduced size and blow it up to whatever size you need

I've done this many times and at a much larger size, than 3' × 4'

 

[JoeRees]

Wow, great responses to my inquiry - thank you all so much for the advice.
FYI, my first attempt at this was to divide the tracing into thirds, photograph them individually and stitch back together before attempting my initial vectorization - this proved useless as apparently all my thirds had significant distortion from being taken at too-close a range. My next attempt was to place my original drawing on the floor and get as far away as I could with the camera, standing on a chair so I could capture a single shot from about 6' away. One came out pretty close using this method but the other was still way off - damn distortion again. I could probably keep stabbing at it and figure out a way to pin to a wall as some suggested, with the camera on a tripod, etc...but my favorite advice from this post is to find a blueprint service that can scan an oversized original and just give me back a distortion-free bitmap to vectorize. I already did a Google search and turned up a few in my vicinity - one of whom I've already emailed asking if they had this capacity. I'll keep you posted on how that works out. THANK YOU THANK YOU!!

 

[JoeRees]

Ok, I found a Minuteman Press 10 miles away from my door that can scan my originals and email me the resulting full-size bitmaps ( or copy them to my portable thumb drive) for $6per page - WHILE I WAIT!!! I'll be going there tomorrow and let you know how it works out. I am so glad I asked smart people, pats on the back for everyone.

 

[54warrior]

Most Staples now have the ability to scan documents that are 3 feet wide . I do this all the time when making templates for Side By Side buggies/UTV's and Four Wheelers.

 

[signman315]

I've used an 11"x 17" cheap $100 scanner and scanned it in multiple pieces and rebuilt it in photoshop. I've mostly done this for fine art reproductions, and the customer's standards were really high, and it worked out great. Time consuming, but no wasted materials or special equipment required. Just be sure to give yourself plenty of overlap for each scan, and also buy a scanner that has the glass flush with the edges. Otherwise you are wrinkling the paper to mush it into the scanner, causing distortions at the edge of the scan and also potentially damaging the original. Best of luck!