ive been thinking about making sewing pattern scripts. they would take in measurements and output a image (bmp, png, or svg). im sure most scripting languages would work for calculating the points for the pattern but i dont know what to use to export the image. any advice would be appriciated.

This sound like a good use-case for svg. Svg is just an xml file with .svg as it's extension.
You can read all about the details over at the w3schools SVG tutorial.

ImageMagick, which is a collection of tools related to image processing, can be used to perform a huge array of different image manipulations including creating an image from scratch. However, if you haven't used it before there's a lot of reading to do before you can competently use these tools in a script.
(but don't let that scare you!)

P.S: If you want to do this as an open-source project, I'd be very interested in participating. I don't know anything about sewing patterns, but I'd be willing to learn.

absolutely open source. I'm surprised there isn't something like it already. also I'd be great full for your assistance

I'll look into the svg tutorial you posted and I was hoping to use imageMagick to export the gimp-editable image. i was also thinking of making it easily openable with OO.org/LO.org draw for scaleable coloring. I hope to use the patterns on spoonflour, a fabric printing company.

Is this the spoonflower you're referring to?

From what I can see they merely take a graphic and print it to fabric.

If I understood you correctly the first time, what you want to do is create a script to do what this website charges for.

What I have in mind here is to design a single piece of software that can take parameters from a pattern file, combine that with measurements input by the end user and output the result.
This is a better way than separate scripts for each pattern.

It would be easier to write a few scripts if you only have one or two patterns, but you'd need to write a new script for each new pattern and that's re-doing work that you've already done.

By starting with a base program that reads a configuration file, you get a true CAD application that others can contribute to even if all they can contribute is a few patterns.

yep that is the spoonflower im talking about. they allow large images to be printed on to fabric. such as a pattern. so instead of wrestling with keeping the fabric flat durring pattern transfer one can print the pattern directly on the fabric. plus one could take the pattern and digitally color inside it. giving full customization to the graphic.

plus when printed, the fabric that's not used could be recycled easier because its not been inked.

as to http://sewingpatterns.com/ , yes the program/script would make the digital version of those which could be printed on anything. paper. sheet plastic, even wood to than be reusable until the medium breaks.

i also agree w/you that a solid program to process scripts would be good, however i plan to start with a simple script or 2 to code out the logic and get a finished product than figure out what is the same and what is different. i find working on somthing which needs not be compiled to test helps with brainstorming. so using scripting as a computable form of psuedo code ^.^