Mini MegaPixel

As well as our main Manchester MegaPixel build at the Museum of Science and Industry, we’re hoping other people in schools, offices, homes and any building with a window anywhere in the world can also join in by making Mini-MegaPixel images, using smaller square pixels and a similar principle. This is our online converter for making a Mini-MegaPixel.

You’ll need an image to convert, a window to put it up in, red, green, blue and black pens to colour it in, and printable sheets of OHP transparency/acetate for our pixel grids. The grids, as well as more instructions and accompanying activities, can be found on the Downloads page.

Step 1: Measure your window

The Mini MegaPixel pixels are 4cm square – you need to measure your window, and give us the size in pixels. For example, if your window is 120cm across, you should put the width as 30.

Step 2: Choose a photo

We recommend your photo is roughly the same shape as your window (square, portrait or landscape – although you will have the chance to crop and scale it in the next step). We also suggest that photos with bright colours, and not too much detail, work best. Before you’re done you can check what your photo will look like as a pixelated version, and come back to this step if you’re not happy.

Drag a photo from your computer onto this panel:

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Or, use this form to select one:

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Step 3: Crop your photo

Select an area of your photo to encode into Mini MegaPixels – drag to move the image around, and scroll or drag the handles to resize it. This rectangle is set up to match the window proportions you gave in step 1.

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Step 4: Tell us about your pens.

If you are using Megapixel-approved Edding pens, select Edding below. Otherwise, you’ll need to determine what colours your pens are – colour a section of blank acetate, hold it up to a window or light source and take a photo of it, then examine that photo and find the RGB values of the pen colour. If you’re not sure, please email and we can help!

The “Ideal” pen setting will assume your pens are “pure” red, green and blue and skip calibration, but no real pens will match these colours – please input your pen colours below.

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Your data is ready.

Real image

This has been scaled up to match the preview image.

Preview image

This is made up of small pixels in the colour of your pens, to give an idea what the final Mini-Megapixel will look like. Adjust the brightness slider until this looks good.

Pixel values

This table should copy-paste into spreadsheet software such as Excel. Each square denotes the number of cells within each pixel you should colour in each colour. (All other cells should be coloured black.)

Quality histogram

Depending on your pens and image, the colour correction step can recommend colouring more squares than there are, or fewer than zero. Those cases are represented by the red bars in this histogram. If the red bars are high (and the preview image looks bad) then you should adjust the brightness slider down.

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