Topics

1

General / align photos default settings

« on: March 13, 2021, 12:45:36 AM »

Can someone tell me the general AND advanced default settings for the align photos portion of the workflow. I was messing around and now I'd like to go back to the default. Thank you.

2

General / scale does not export

« on: December 15, 2014, 10:31:39 PM »

The scale I set in PhotoScan does not seem to carry over when I export models to third party software (Meshlab or Geomagic).

In PhotoScan, I set scale on a model by placing two points. I know the distance between these points. I highlight the two points in the Ground Control panel, then select "Create Scale Bar." I enter the distance between the two points. Then I export the model in ply.

The scale is not retained in Geomagic or Meshlab. Is there a step I am missing?

A separate question: in the Ground Control settings, I am able to change the measurement accuracy settings. For example, the default scale bar accuracy is 0.001 m. Do I get better scale bar accuracy if I change this setting to 0.000001?

3

General / ply in ascii format

« on: December 15, 2014, 08:04:44 AM »

I am trying to export PhotoScan models to a a program (the geomorph package in R) that requires ply files to be in ascii format. On export, I unselected the "binary" option, hoping this would do the trick.

When I attempted to open the files in geomorph, the files were unreadable. The error message says the object's dimensions are greater than its length. I spoke with one of the developers of geomorph, and she said she thinks the ply file has duplicated vertices and so it is not able to match up the vertex coordinates to the triangles

Basically, I'd just like to find a solution. Any ideas?

4

General / Scale, volume, surface area on discrete object (not a mapped surface)

« on: October 03, 2014, 08:41:01 PM »

FYI I use PS Professional edition, v. 1.0.4....

SETTING SCALE: I took a bunch of images with scale bars affixed to the turntable. I'd like to use these scale bars to set scale on the object itself.

Questions:
1. Do I place the markers on the scale bar in the photos themselves?
2. If not, I guess that means I need to model the scale bar as well as the object, and then place the markers on the scale bar, yes?
3. If so, in how many photos do I need to model the scale bar?
4. If I have more than one chunk, do I need a separate scale bar from each chunk?
5. Alternatively, I could place markers on the model of the object, measure the distance between those locations on the object itself, then set scale by scaling the object to that distance between markers. In fact, this is the approach I have currently taken. Is this as accurate as using the scale bar? Let's say I take three measurements on the object itself. For simplicity, let's say I take a length, width, and height measurement. Each measurement has error. If I place markers on the model to replicate these three distances, because of measurement error, each distance will suggest a slightly different scale for the object. How does PS handle these conflicting scale measurements? Averaging?

SURFACE AREA AND VOLUME: Having set scale for my object using a single measurement, in the manner described in question 5 above, I would now like to estimate surface area and volume for my object. To do so, the PS Manual instructs me to choose the "Measure Area and Volume" from the Tools menu. My tools menu does not have a Measure Area and Volume option. Where is it?

Screenshot attached. It's a metatarsal (toe bone)... get your mind out of the gutter

Thanks.

5

Bug Reports / Post attachments bug

« on: September 30, 2014, 04:44:37 AM »

There's a bug in bug reporting on your new website. The post will not accept attachments.

6

General / Using physical markers in "background" to improve alignment

« on: September 25, 2014, 09:04:41 PM »

Several posts have suggested that when alignment is difficult using the object only, having physical markers in the "background" can improve alignment. For example, you could place the object on a newspaper, in which case the text of the newspaper, unmasked, would be incorporated into the alignment calculations.

I am trying to figure out how to make this work for my imaging sequence. I'm making models of skulls (and other bones). I place the skull on a turntable and rotate the turntable to surround the skull with images. I surround the skull with images on 3-6 axes. Some of the skulls are very undifferentiated in terms of color and topography, and thus difficult to get good alignment.

To create physical markers, I can tape a page of newspaper onto the surface of the turntable. Then I can align separately for each axis around which I have taken images. The remaining steps are unclear to me.

Ultimately, I want a model of the skull without the newspaper. But each aligned chunk will contain a model that includes the newspaper. So, when do I merge chunks? And when and how do I remove the newspaper reconstruction from my model?

Thanks again.

7

General / Choosing optimum dense cloud quality

« on: September 22, 2014, 07:48:24 PM »

I have been surprised to discover that "High" and "Ultra High" dense cloud quality settings do not necessarily produce the most accurate geometric reconstructions. An example is provided in the attachment. While neither low nor high quality is perfect (it's a difficult surface, and I need to light better I think), Low is clearly a closer representation of the surface. Both models have the same polygon count.

For other objects, I have found High superior to Low.

My question is whether there is a way to know in advance which cloud quality setting will be optimal, or is this trial and error for each object (or perhaps each class of objects)?

Other ideas for getting a smoother 'vault' are very welcome.

Thanks.

8

General / Identifying misaligned photos

« on: September 21, 2014, 10:51:34 AM »

Is there a way to determine which images aligned improperly during photo alignment? In the attached screen shot of the sparse cloud of a skull, almost all the images have aligned well. However, a few images are approximately reflected about the base of the skull. To guide you to looking at this sparse cloud, the red arrow points to the eye sockets of the sparse cloud for the photos that aligned well. The yellow arrow points to the second set of eye sockets, from the misaligned photos.

If I could find out which images misaligned, I would simply delete them from my data set, as everything else is in good working order.

Thanks.

9

General / PS Crashing during "Build mesh"

« on: September 13, 2014, 10:44:03 PM »

PhotoScan has been crashing all day at the Build Mesh stage. I have re-installing the software. I have tried 3 different drivers for my GPU. The GPU is an Nvidia GEForce GTX 580.

First driver, 332.11: Crash during meshbuild. Second, 337.88: Crash during meshbuild.

Finally, I went back to the most recent driver (340.52). For reasons explained in other threads, this driver doesn't work with PhotoScan. Processing gets rerouted to the CPU. So far, however, I can build a mesh this way. Whether that continues, I obviously don't know.

I'm attaching the reports from two of the crashes. I'm curious if there's anything in these that explains the crashes. Doesn't seem like it.

10

General / PS detects duplicate GPU

« on: September 11, 2014, 09:13:10 PM »

A couple of weeks ago I had to roll back the driver on my GPU so that it would work in PS. Ever since that time, I show a duplicate of the GPU in my OpenCL window. It may not be causing any problems, but it can't be helping.

Is there a way to remove the duplicate? Should I bother?

Should I tick off one or both GPUs in the OpenCL screen?

Thanks.

D

11

General / Dead topic: please ignore/remove

« on: September 11, 2014, 09:04:33 PM »

Some information in this post was erroneous. I've taken it down. Sorry for the trouble.

12

General / "Fine" vs. "Normal" quality JPEGs

« on: September 05, 2014, 12:31:17 AM »

I'm shooting with a Nikon 12 mpx. It has 3 options for JPEG image quality: basic, normal, and fine. File size increases as quality increases.

Should I expect to get better images, for use in PS, with the "fine" setting, or is this not relevant? Will setting image quality to "fine" cause any potential problems?

Thanks.

13

General / Overlapping photos... good, bad, indifferent?

« on: August 25, 2014, 11:57:10 PM »

Hi,

I've been trying to create models of some bones that are difficult to model in PhotoScan, because the surfaces are so smooth and reflective. I've finally managed to set up a lighting and image capture procedure where I can get photographs to align: rotate the object on a turntable, 6-8 different chunks/rotations, take a relatively high number of photographs (e.g., 30) per rotation, align chunks separately, then merge chunks sequentially.

However, as you can see from this screenshot, I get a large number of photographs that overlap one another at the two ends of the rotation. I was once told overlapping photographs were a bad thing in PS. But it doesn't seem to be causing me a problem with alignment (whether the shape is accurate remains to be seen).

So my question is: are overlapping photos a matter of concern or not?

Thanks.

DCK

14

General / Automated masking issue

« on: August 19, 2014, 09:31:17 PM »

Hello everyone,

I'm having a problem with automated masking that I didn't have with older (>1 year older) versions of PhotoScan. I'm not sure if it's something in the software, or something I'm forgetting about stepping through the process. The attached image pretty much explains the problem. When I use the mask from one image to mask additional images, the imported masks hold onto the shape outline of the original mask. As you can see, the masking of the object (a monkey hip bone) in the additional images is pretty good. I can play with tolerances to find a useful automated mask. However, the retention of the shape from the original mask makes these automated masks useless.

Here's my process.
1. Pictures taken with specimen on turntable.
2. Mask one image.
3. Export mask (either for active chunk or for current photo... makes no difference in end result)
4. Import mask for active chunk.

Any help is much appreciated.

DCK

15

General / Developing RAW to JPEG

« on: August 13, 2014, 10:33:33 PM »

I have been using the default JPEG images output from my camera, but am considering shooting and then developing RAW to JPEG.

I am not a photographer, and don't know anything about this process. In what software is the developing usually done? Is there freeware available that will do the trick? Is it an idiot-proof, automated process, or does it require me to make image-by-image judgments?

Thanks for any help.