Topic: Convert point cloud to a mosiac, here's how

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charliewallace (Over 1 year ago)
Here's a technique to extract a 2-D image from your synth - maybe from a synthetic viewpoint - and create a semirealistic scene, with a cool mosaic texture. The sample is a sea cliff at Torrey Pines State Reserve, north of San Diego:
Photosynth this is from:
How it's done: (1) hit P to turn off the photos. (2)Reposition/rotate the point cloud to the desired view (I recommend the DirectX viewer, but it's optional), (3) hit alt-PrtScn to capture the screen, (4) paste into photoshop, (5) select filter/Other/Maximum, (6) adjust radius, I used about 3, and apply. The points are converted to squares, that retain some of the original color from the scene.
If you try this, Please Reply!!!!
Nathanael (Over 1 year ago)
Hey, Charlie,

Nice tip! This is very similar to the effect given by viewing the pointcloud fullscreen at a very low resolution. (I recommend a CRT monitor in addition to the Direct3D viewer if you'd like to try that.)

Another take on your technique would be to get a screen capture of the pointcloud when the viewer is windowed (that is to say "not fullscreen"), crop it down to just the viewer in your favorite image editor, and then resize the entire image to a higher resolution (be sure that the new higher resolution is the same aspect ratio as what you started with, though). If resized with the "Pixel Resize" filter (which is about the most primitive scaling method possible) the original pixels will remain sharp cornered squares when enlarged.

Then you could use Dilate or Erode type commands (found under Edge Effects in Paint Shop Pro) to adjust the radius of each point as desired.
Nathanael (Over 1 year ago)
Getting a little more geeky, here are a couple of other interesting tweaks:

>> Duplicate your final sized pointcloud to a new layer, apply a Gaussian blur to one of the copies and set the top layer's filter to 'Lighten'.

>> If you'd like your pointcloud to be against a white background, either first use the Negative Image tool to flip the background to white, then use the Hue tool to rotate your hues 180 degrees to where they began. This will still result in the shadows and highlights in your pointcloud being backwards, though. 

A potentially better method would be to use the Magic Wand on any pure black pixel (preferably before adjusting the radius of any of your points), making sure your Magic Wand has it's tolerance set to zero and that it is not confined to selecting only the black pixels that are touching the one that you've just clicked on. The easiest way to change all of those pure black pixels to white is to just delete them out of your current layer.
Nathanael (Over 1 year ago)
(continuing) Then simply insert a layer of the color of your choice underneath your pointcloud layer. Come to think of it, this second method of background color changing is infinitely superior to the first.