Comments on: Wall Graphics

Question: Wall Graphics

Sreiny — Sun, 15 Oct 2006 20:33:25 -0800

Converting an image to a simple dot-matrix pattern?

A section of my wall is concrete and so I can't hang anything on it. I am planning on buying a few thousand color labels and creating an image in a dot-matrix style. This is a bad example
but kind of along the lines of what I'm thinking of doing, except with an image. Is there a program or application that I can download to convert an image to a dot matrix grid. Basically what I'll do is set up a grid in Illustrator to plan it out, and either there'll be a sticker there, or there won't.

To focus the answers a bit, this isn't a job for Rasterbator or photoshop halftone filter, it needs to be gridded with an "either there's a dot there or there isn't process." Thanks.

By: delmoi

delmoi — Sun, 15 Oct 2006 20:46:39 -0800

Well, just convert it to a bitmap image in photoshop, that's how I did this image.

By: smackfu

smackfu — Sun, 15 Oct 2006 20:47:58 -0800

What delmoi said. You do have to convert to Grayscale first, because Photoshop won't let you go straight to Bitmap.

Also, you can play with the pixel aspect ratio, under Image, if your labels aren't square.

By: Fins

Fins — Sun, 15 Oct 2006 20:48:31 -0800

Crosstitch image conversion might work. One source.

By: stopgap

stopgap — Sun, 15 Oct 2006 20:48:42 -0800

I would just resize the image so the dimensions in pixels is the same as the dimensions you want in your color labels. Then reduce the palette to just the colors that you have labels for. The image is then essentially just a matrix of colored points. Zoom in and turn on pixel gridlines if it helps, then replicate on your wall!

By: aspo

aspo — Sun, 15 Oct 2006 21:03:56 -0800

Stopgap has the right idea, but I'd reduce the palette first, it will give you better results.

By: brain cloud

brain cloud — Sun, 15 Oct 2006 21:04:45 -0800

This probably isn't quite exactly what you are aiming for (because it does ascii, not dots) but perhaps with some tweaking it could do the job.

By: stavrosthewonderchicken

stavrosthewonderchicken — Sun, 15 Oct 2006 21:09:29 -0800

The Rasterbator

By: doctor_negative

doctor_negative — Mon, 16 Oct 2006 05:50:14 -0800

- establish a grid unit size (let's say 2"x2" as an example)
- establsih your overall image size (let's say 4'x4')
- that means you have a 24x24 grid
- in Photoshop, convert your image size to 24 x 24 pixels
- convert to greyscale
- covert to bitmap: conversion method here will determine the overall look of your image. Diffusion will give a dotted stippled look, 50% threshold will give you a stark black and white. Custom patten can do interesting things (try a small black to white vertical or horizontal gradient as a pattern). Pushing the values around with levels or curves can give you more control in this step.
- Now you probably have a smaller image that you want. Go to Image Size, set the overall size value you want. Set the Resample mode to Nearest Neighbor. Resize.
- Bring this into Illustrator, lay down your grid lines on top.

By: Sreiny

Sreiny — Mon, 16 Oct 2006 05:54:00 -0800

I suppose these are things I should know, but aspo, could you explain how to reduce the palette first? Does that just mean reducing the image to 2 color? Thanks.

By: doctor_negative

doctor_negative — Mon, 16 Oct 2006 10:25:20 -0800

I suppose these are things I should know, but aspo, could you explain how to reduce the palette first? Does that just mean reducing the image to 2 color? Thanks.

Image/Adjustments/Posterize. You can select the number of colors.

If you're going for more than 2 colors, then the bitmap conversion won't work. But if you replace the bitmap step with posterize and you can still basically follow the steps. The problem with posterize is that has no application method choice. If you instead, convert it to Indexed Color, you can pick the number of colors and the application method.

By: doctor_negative

doctor_negative — Mon, 16 Oct 2006 10:29:27 -0800

OK, this is ultra geeky but you could also convert each channel to bitmap separately and then recombine them in in a new RGB file.

By: hatsix

hatsix — Tue, 17 Oct 2006 19:51:38 -0800

You want the rasterbator, linked above.

By: hatsix

hatsix — Tue, 17 Oct 2006 20:02:01 -0800

I should expound, since you said "no rasterbator"... you want to reduce colors using posterize THEN convert to indexed colors, then Rasterbator

By: stavrosthewonderchicken

stavrosthewonderchicken — Tue, 17 Oct 2006 23:22:05 -0800

Sorry, I missed the 'no rasterbator' bit above.

By: psyward

psyward — Fri, 20 Oct 2006 04:43:38 -0800

I agree with doctor_negative on this one, use a grid the size/ratio of your wall.

Once you've established that, establish a formula for each "dot".

i.e. if the square here has a brightness above 50%, then its a dot.

A more complex, but similar system can be found here. You can even use it as motivation / brainstorming.

Good luck, and maybe post a pic when you're done.