FAQ’s

User Bias

The user should take special care not to inadvertently bias the sample by altering the method in which image samples are taken, setting the scale improperly, selectively editing the net or changing the EDP between samples that will be merged to each other. All analysis of a study should be performed in the same way. Be systematic and develop a routine for image acquisition and analysis.

Please refer to section 3.0 of the Sampling and Analysis Guide for more information.

What can we do to resolve more fines?

If you wish to resolve smaller particles, there are two options. You can choose to use a higher zoom lens. Zooming in allows the system to resolve the smaller particles much easier. It can, however, reduce the number of the larger particles analyzed. The other option is to update your camera. New camera technology has allowed us to greatly increase the minimum resolvable particle size within images and still keep the larger particles within the results. By moving from the standard 0.3Mp camera to one of our 2.1 or 10.7Mp options, you can increase your resolved particle magnitude from 43x to 267x. Simply put, your system will be able to analyze particles up to 1/8th the size of the smallest particle that your system is measuring now.

Why should I avoid wide angle lenses and digital zooming?

Digital zooming reduces the definition in your images. When you choose to digitally zoom, your camera is actually cropping and expanding the image. This effect makes it appear as if the image has been zoomed in. The problem is, when the camera expands the image, it needs to interpolate pixels which reduces the clarity and definition of your photo. Wide angle lenses should be avoided as well. In order to obtain a wide format image, distortion is created at the edges of the photo. The wider the lens, the more distortion there is.

What should I use as a proper scale?

WipWare recommends using any solid scaling device with a contrasting colour to the material which can be laid down flat onto the material in question. Range rods, yard/meter sticks and customized frames can all be used. WipWare discourages the use of balls as they can expand and contract with changes in temperature and altitude. Be sure to have the scaling device perpendicular to the camera. Be sure to use two scaling devices when you cannot be parallel to the sample. This will allow you to use the tilt-correction within the software for more accurate results. If in doubt, use two scales. One in the foreground of the sample and one in the background.

Are high resolution images better than small resolution images?

Large and small images each have their pros and cons. Fines can be delineated easier with larger images and tend to get fused together with smaller images. Oversize is usually analyzed properly with smaller images but tends to get slightly disintegrated in larger images. Smaller images analyze and are edited much faster than large images. WipWare always recommends taking the original images at a high resolution. It is always possible to downsize the image without distortion, but nearly impossible to make an image larger while keeping clarity and definition. As a rule of thumb, if you cannot delineate the particle with your eye, the software will be unable to as well.

Digital Image Sampling Basics

When acquiring image samples each image should:

  • Contain an easy to read scale (two for tilt correction).
  • Be high definition – Not necessarily high resolution.
  •  Never be taken with a wide-angle lens.
  • Contain clearly visible particles (if you can outline each individual particle, the software can too).
  • Have even lighting (avoid hot spot/shadow areas if possible).

For more information please read the Sampling and Analysis Guide

Image Acquisition

The most important thing about photoanalysis software is the quality of images that are used for the analysis. Image Acquisition – The better the images, the better the results. Develop a sampling strategy. Taking images is like taking samples for sieving or other tests. The results must statistically represent the product as a whole. To adequately compensate for rockpile segregation and heterogeneity, each image must contain a sufficient number of fragments, and the results from dozens of images per blast must be merged and averaged. Accurate estimation of larger blocks in particular requires merged data because of the scarcity of such blocks. High-fidelity, high-speed automatic edge detection is essential – methods that rely on tracing or manual editing are incapable of processing sufficient data and so are prone to large sampling errors.

  • Fill the field of view with fragmented rock, preferably at least 200 particles.
  • Include all sizes. No single block should occupy more than 20% of the width of image. For improved resolution of fines, use WipFrag's zoom-merge capability to combine images at different scales of magnification.
  • Beware of rockpile segregation. Large blocks tend to roll to the outer edges and fines may cover the surface or become hidden as a result of gravity or rainfall. The effects can be minimized by increasing the number of images per sample but only with careful selection of image locations.
  • Don’t waste an image. Get images of the particles in question, not the sky and area around it.
  • WipFrag measures what it can see. If your pictures are far away, fines will not be resolved. If the image is taken too close, oversize may be missed. Get a good mix of images of the sample in question.

For more information please read the Sampling and Analysis Guide

Can a lost license key be replaced?

Lost license keys cannot be replaced; WipWare recommends that the license key is insured for the replacement value of the software product to protect against loss or theft. Damaged license keys can be exchanged for a nominal cost; Keys that have been damaged due to tampering may be replaced at the discretion of WipWare.

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