DPI vs. PPI - What's the difference?

[Gamerprinter]

For my own purposes, and this really is for everyone, since I have been getting more and more into Virtual Table Top software of late, I would like to see more maps that are "agnostic" to the game system. What I mean by that is no grid. Grids just get in the way of using a VTT because VTTs have their own grid overlays usually. Also, if text could be removed that would be a great addition as well.

Basically two versions of the map are needed for VTTs. One complete (text and grid) and one clean (no text or grid). The complete one is for GM reference and the clean one is to play on.

Finally, all maps should be created at a scale of 200 pixels equals 5 feet. That will make it usable across almost every VTT with the understanding that some VTTs will need to rescale, but it is easier and cleaner to scale down rather than up.

That said, I would love to eventually play on this map. *hint* *hint*

Can't wait to see what the others produce.

RP, although I've been creating hand-drawn and digital maps for many years, I've never included a grid, until this year, because I wanted my maps to be more universal in use. With your mention of VTT, I see a huge opportunity to my maps to a different and perhaps larger audience.

Its true my business is printing maps, but map creation and distribution is also at the heart of what I do and finding a way to target the VTT audience is one of my goals.

The maps produced here were not saved to any specific pixel resolution to be used specifically for gaming with - I only made them large enough to show detail for anyone who might download a closer view.

That said, I have no problem providing through this thread the final versions of each map at 200 dpi with and without gridlines. (Of course if the outside map is too large, megabyte-wise for this site, I may have to break it up into multiple maps.)

[RPMiller]

Just to clarify, not 200 dpi (dots per inch), 200 pixels = 5 feet (scale).

Cool. Look forward to seeing them. As for the VTT audience, you should probably immerse yourself into those forums to get an idea of what is expected and what people want to see.

[Gamerprinter]

If I create my graphics with a scale of 1 inch = 5 feet, and resolution to 200 dpi (dots per inch), isn't that the same as 200 pixels per 5 feet?

[RPMiller]

You are over complicating it. As I explained in the reply to your PM, we don't care what the dpi is. We aren't printing it. What is a dot on the screen, how does that compare to a dot on a printer? Just keep it simple.

[Midgardsormr]

Heh. I think the answer to the question is "yes." DPI may not matter to you, but I suspect it might to Gamerprinter!

[RPMiller]

Not in this instance. He is talking to me specifically about VTTs. There is no need to print when you are playing directly on the screen, but I get the irony of the statement and his name.

[Gamerprinter]

A digital image is measured in pixels. When a pixel is printed, it is represented by a dot. Therefore dpi and ppi is the same thing - one in its digital format only (pixels), the other in print (dots).

All graphics are measured interchangeably as dpi or ppi - I've got software that refers to both.

A 200 dpi or ppi image is measured as 200 x 200 dots or pixels. Most software I use only refer to dpi, even when an image is never intended to be printed.

So the issue is semantics. Unless you've got some other specific way to describe 200 pixels = 5 feet, there's only one way for me to make it.

So I do believe I am correct. I am not making it more complicated. The software I refer to mentioning ppi was Micrografx Picture Publisher and it nolonger exists. All other graphics software refer to dpi interchangeably with pixels.

Its a simple question.

[Robbie]

Nice work GP...I'm also quite thoroughly impressed with the exterior map...The interior map shows a LOT of work done, but for my own tastes it may be a wee bit too texture heavy...I'm not saying thats a bad thing, as I'm more of a minimalist in my approach to mapping...I definitely agree that these would go really well with VTT.

As for the dpi/ppi/200 argument...there is no argument really...200 pixels per 5 square feet = 200 dpi scaled print for D&D size miniatures = good for everyone

[RPMiller]

A digital image is measured in pixels. When a pixel is printed, it is represented by a dot. Therefore dpi and ppi is the same thing - one in its digital format only (pixels), the other in print (dots).

All graphics are measured interchangeably as dpi or ppi - I've got software that refers to both.

A 200 dpi or ppi image is measured as 200 x 200 dots or pixels. Most software I use only refer to dpi, even when an image is never intended to be printed.

So the issue is semantics. Unless you've got some other specific way to describe 200 pixels = 5 feet, there's only one way for me to make it.

So I do believe I am correct. I am not making it more complicated. The software I refer to mentioning ppi was Micrografx Picture Publisher and it nolonger exists. All other graphics software refer to dpi interchangeably with pixels.

Its a simple question.

Nice work GP...I'm also quite thoroughly impressed with the exterior map...The interior map shows a LOT of work done, but for my own tastes it may be a wee bit too texture heavy...I'm not saying thats a bad thing, as I'm more of a minimalist in my approach to mapping...I definitely agree that these would go really well with VTT.

As for the dpi/ppi/200 argument...there is no argument really...200 pixels per 5 square feet = 200 dpi scaled print for D&D size miniatures = good for everyone

While I understand and appreciate and agree to some extent with your assessment of dpi, it is not entirely accurate. As I've mentioned I have a background in reprographics from 15 odd years ago as well as some formal training in the area of computer graphics. This dpi/ppi argument has been around a long time and unfortunately those that don't fully understand it are in the majority and even the application designers get it wrong sometimes because of the way the older software worked and used the terms.

Here is just one of many links that you can find on the subject, but I picked this one specifically because it has print shop links as well. Please understand that I'm not trying to be a jerk about this, and I agree that we are essentially saying the same thing, and in this instance it isn't important as the software obviously is doing it correctly, but we really should be using the correct terms and it is always good to learn something new. I've talked to many reprographics folks over the years and many of them get this wrong because they are usually self taught or don't have the diverse background that would have introduced them to the differences in the terms. Not to mention, as I stated, the software itself is misleading.

http://www.rideau-info.com/photos/mythdpi.html

I would encourage everyone to investigate this further, and if we want to discuss it some more, since it definitely falls into the realm of this site, I think starting a new thread would be a great idea.

[ravells]

Might be worth moving the relevant posts from here to a new thread too for when people come to look at the threads come judgement day

Ravs