Messages

61

General / different camera heights --> resulting resolution?

« on: May 10, 2011, 03:23:10 PM »

Hi I have taken >1000 pictures from a landscape with a helikite.
for most of the pictures, the camera was at altitudes between 50m and 150m.

Because photographs which were taken at lower camera elevations (e.g. 50m) have more spatial resolution than photo's produced from higher camera elevations (e.g. 150m), the question is how PhotoScan deals with photo's with different resolution and field of view, resulting from different camera heights?

Let's say for example that 900 pictures where taken at 50m height, and that those 900 pictures are enough to build the textured 3D model in PhotoScan. Let's further say that there are also 100 pictures that were taken at 150m height with lower resolution and higher field of view.

How will PhotoScan process this mix of 1000 (900+100) photos. Is it smart enough to leave the 100 low resolution photos out, because this will improve the resolution of the model? Or how will Photoscan deal with this situation if this is not the case, for (i) the alignment process, (ii) the geobuilding process, (iii) the texture building process and (iv) the orthophoto process?

This is important for me, because this may mean that photo's taken from a high elevation are best left out of the set of photos which is used as input in Photoscan. The problem here is that I don't know at forehand if the set of photo's is then sufficiently overlapping.

Kind regards,
Jan

62

General / Re: Best PC configuration for PhotoScan ?

« on: April 29, 2011, 11:15:25 AM »

the amount of RAM only limits the amount of photos you can process,

So, if you are sure you will not process more photos in the future than you do now, you can keep your RAM low (4 GB or 8GB)

to improve speed, I think the more cores the better, and also the speed of the cores matter. Therefore I think the i7-990X is one of the best options available now, it has 6 cores running at 3.46 GHz.

also hi-end videocards (e.g. geforce GTX590) can further improve speed with openCL. But the speed gain of the videocard must be higher than the speed loss of one core, because you will have to sacrifice one core for each graphics card you use for this purpose, as said somewhere in the manual.

63

General / Re: Best PC configuration for PhotoScan ?

« on: April 28, 2011, 01:03:05 PM »

Hi Gatto,

you can look at another page of Agisoft:
http://www.agisoft.ru/products/photoscan/performance/

I'm no pro, but with 3000$, I would by something like this:

a i7-980X hexacore processor

search a motherboard which can handle 24 GB of RAM and buy 24 GB of RAM

buy 2 GeForce GTX 480 graphic cards given that two of those fit into your motherboard into your motherboard

64

Feature Requests / Re: Feature requests

« on: April 28, 2011, 12:44:50 PM »

It would also be interesting if photoscan automatically rejects overabundent photographs. So that you don't have to worry which selection of photographs is the most appropriate for making the model.

For example: Suppose that I have 500 highly overlapping photographs. Because processing 500 photos costs much time, I can select 100 out of 500 which are sufficiently overlapping to build the model. However this selection (a) costs time, and (b) it is unsure which selection to use for the best outcome. It would be great if photoscan automatically selects the needed photographs out of those 500 for the best given result.

65

Feature Requests / Re: Feature requests

« on: April 27, 2011, 06:48:42 PM »

It would be nice if there was an option so that the alignement process and the geometry building could be processed in a single run. In that way, the most time consuming parts of the model building processes could run alone at night.

66

General / Re: autofocus

« on: April 20, 2011, 09:42:02 PM »

In short:

Is it a problem for Photoscan that the camera will autofocus at short distances, and that the focus will not be fixed on infinity?

67

General / autofocus

« on: April 20, 2011, 12:00:26 PM »

Hello Dmitry,

When building a 3D model from photos which are taken from about 1.2 m from above a horizontal flat object,

the flat object doesn't appear flat when using camera calibrated parameters in photoscan.

Surprisingly, sometimes photoscan produces a flat model with default uncalibrated camera parameters, but not always.

I have also photographs from a great height (>50m) and than the model is realistic when inputing calibrated camera parameters.

Is it possible that these biased models have something to do with the autofocus of the camera when photographing close objects, as the focus is set on infinity when I photographed from great heights.

Is it possible to acquire a realistic model when photographing an object from about 1 meter ?

Thank you,
Jan.

68

General / Photoscan on MAC and LINUX/UNIX?

« on: December 17, 2010, 04:04:39 PM »

Hi,

is it possible to run photoscan on MAC or LINUX,

we have some (very) powerfull computers here on the university,
but they only have MAC or LINUX/UNIX as OS.

We have a MAC PRO octocore with 18GB of RAM, and the calculation centre has a supercomputer which runs on LINUX

I know the executable is only for Windows, but maybe there is a trick?

I love the program, but I need to process a lot of pictures

regards,
Jan