Page 1 of 2 12 LastLast
Results 1 to 10 of 16

Thread: Ridiculously odd question: Measuring Area

  1. #1
    Guild Apprentice
    Join Date
    Jul 2007
    Posts
    40

    Post Ridiculously odd question: Measuring Area

    Alright, I have a nearly finished map, and now I need to measure the area (in square miles) of certain regions. I have a scale, and I even know how many square miles each pixel is on my map (about 17 square miles), but I can't find a tool in photoshop to give me a pixel count.

    Does anyone know of a trick to measure areas in irregular shapes?

    Thanks. Here's my country shape, with a scale (in miles) if anyone thinks they can offer advice. I'll probably have to cut triangles out of it since I know how to measure the area of triangles. Being a little off won't be that big of a deal.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	Holylands Outline.bmp 
Views:	425 
Size:	413.1 KB 
ID:	10068  

  2. #2
    Community Leader Facebook Connected Steel General's Avatar
    Join Date
    Jun 2008
    Location
    Ft. Wayne, IN
    Posts
    9,464

    Default

    In Photoshop IMAGE > IMAGE SIZE will give you the total # of pixels for the entire image, I don't know how (if it's even possible) to get the # of pixels in a selected area.
    My Finished Maps | My Challenge Maps | Ghoraja Juun, my largely stagnated campaign setting.

    Unless otherwise stated by me in the post, all work is licensed under a Creative Commons Attribution-Noncommercial 3.0 United States License.



  3. #3
    Software Dev/Rep Redrobes's Avatar
    Join Date
    Dec 2007
    Location
    England
    Posts
    4,807
    Blog Entries
    4

    Post

    it come up before :-

    http://www.cartographersguild.com/showthread.php?t=2279

    read to the bottom as the process gets easier and easier as we worked out better ways to do it. If you using Gimp then Rob wrote a script to do it - as he always does

  4. #4

    Post

    I don't think its ridiculously odd, I think its keen and insightful and shows a brilliant mind and attention to detail - I asked the same question last June...

    The cheap and cheerful way is to download a copy of paint.net. This is actually a very flexible free graphic editor, but for this you want its selection tool. Open your image in the program select the area and look at the lower left corner of the screen --- # of square pixels.
    You can select for contiguous areas or draw with a lasso type tool.

    http://www.getpaint.net/

    Other solutions exist but mostly cost money. The downside, I think, is that pixels are wider than they are tall some other methods report different area.

    Autocad has an area calculator that seems to consistently report bigger numbers.
    Creative Cartographer (another cad based app) also has an area calculator.
    Gimp and Photoshop both give you information in their Histogram window that can help you calculate # of pixels - best refer to link....

    http://www.cartographersguild.com/sh...?t=2279&page=2

    Finally for a nuts and bolts example here is a thread on the Harn site Lythia.com that has people solving the problem with Autocad.

    http://www.lythia.com/forum/viewtopic.php?f=9&t=10067
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	area.jpg 
Views:	358 
Size:	77.3 KB 
ID:	10070  
    Last edited by Sigurd; 02-07-2009 at 01:13 PM.

  5. #5
    Administrator RobA's Avatar
    Join Date
    Apr 2007
    Location
    Niagara, Canada
    Posts
    5,567

    Post

    Quote Originally Posted by Redrobes View Post
    it come up before :-

    http://www.cartographersguild.com/showthread.php?t=2279

    read to the bottom as the process gets easier and easier as we worked out better ways to do it. If you using Gimp then Rob wrote a script to do it - as he always does
    Sorry RR - I can't take the credit for that one

    Isomage cobbled together the gimp script that can calculate the area and perimeter of a selection:

    http://www.cartographersguild.com/showthread.php?t=3681

    -Rob A>

  6. #6
    Software Dev/Rep Redrobes's Avatar
    Join Date
    Dec 2007
    Location
    England
    Posts
    4,807
    Blog Entries
    4

    Post

    Oh yes sorry Isomage

    Rob, your reputation as 'the scriptmeister' was preceding you there. We have about 3 or 4 Gimp scripters now then - which is very cool.

  7. #7
    Community Leader Facebook Connected Steel General's Avatar
    Join Date
    Jun 2008
    Location
    Ft. Wayne, IN
    Posts
    9,464

    Default

    This may have been covered in the post from a few months ago, but I figured I'd post it anyway...

    If you use the magic wand tool in PS and then click on the histogram tab, it will display the total number of pixels in the selected area.
    My Finished Maps | My Challenge Maps | Ghoraja Juun, my largely stagnated campaign setting.

    Unless otherwise stated by me in the post, all work is licensed under a Creative Commons Attribution-Noncommercial 3.0 United States License.



  8. #8
    Guild Apprentice
    Join Date
    Jul 2007
    Posts
    40

    Post

    Awesome. Thanks everyone for the replys. The Histogram trick will be what I'll use.

  9. #9
    Guild Apprentice
    Join Date
    Nov 2007
    Location
    London, UK
    Posts
    25

    Default

    Excellent. Now, if someone could come up with an easy way of calculating continent-size areas on a globe ...

  10. #10

    Default

    Get a scale that can measure very precisely. Print out map. Cut out area in question. Weigh.
    Cut out a square of measured size out of same paper and weigh.

    Do the math

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •