Blueprint House

On Tue, 19 Nov 2002 15:35:07, in alt.graphics, ltd_ed wrote:

I am really sorry if this is not the correct group to post this request, but I am kind of at a loss as to where to start. I need to find a software package that can take a picture and morph it into an outline sketch. This is going to be used to take a picture of a finished house and convert it into something like a architect's drawing of the house front. Does such an application exist? And if so does anyone know of the name of it or the company that would produce it?

Here's my response, graphically

• First, I found a picture. I entered the search string "house" into Google's images.google.com search engine. (I also chose "Very Large" size in the Advanced search options.)

  I found this picture, which was found by Google on this page.

  

• Second, I loaded it into The GIMP, a free, 'Open Source' image tool for Linux, Unix and Windows. It's quite similar to Adobe's Photoshop, just without the price tag. (Without any price tag, actually!)

• I tried a few of the "Edge-Detect" tools in The Gimp, under "Filters." The one that worked best for me was "Sobel":

  

• The lines were a little thin and dark, and didn't look so good, though, so I used the "Curves" tool under the "Image->Colors" menu in The Gimp to lighten them, which caused them to look much better and thicker!

  

• Now I was ready to turn black into blue. This is simple using the "Color Exchange..." option in the "Image->Colors->Map" menu.

  I chose 100% black as the "From Color", and a blue color (Red=25%, Green=25%, Blue=80%) for the "To Color." Now, this would only turn the few, truly 100% black pixels in the image into the blue I wanted, so I bumped up the "Threshold" values in the "From Color." A 2/3rd threshold (66%, or 171 out of 255) seemed to work well, as you can see!

  

And that's how I turned the photo above to the 'blueprint' style picture below. I'm not sure if that's exactly what 'ltd_ed' wanted, but... :^)

Unfortunately, not having the money to spend a hundred dollars on a Microsoft Operating system, let alone the hundreds for a copy of Photoshop, I'm unfamiliar with how you'd do that using that program.

The Command-Line Way

jpegtopnm IN.JPG | ppmtopgm | pgmedge | pgmtoppm blue-white | pnmtojpeg > OUT.JPG

Here's the result!

Cool, huh!? And it took no interaction from me. In went the input file, out came the output file.

It's not exactly the same, because I didn't tweak the contrast, and I chose pure blue, versus the lighter blue I used in The Gimp, but you get the idea! Change one word in the command and you could get another color.

Enjoy!