WO2010063570A1

WO2010063570A1 - Method and system for identifying rocks

Info

Publication number: WO2010063570A1
Application number: PCT/EP2009/065322
Authority: WO
Inventors: Angelo Menuzzo; Leonardo Maria Giannini; Eleonora Paris
Original assignee: Anpa S.R.L.; Universita' Degli Studi Di Camerino
Priority date: 2008-12-01
Filing date: 2009-11-17
Publication date: 2010-06-10
Also published as: ITTV20080155A1

Abstract

A method for identifying a rock, which comprises the steps of obtaining (101) at least one sample of the rock; generating (102) one or more digital images of the sample; sending (103) the digital images to a processing system; reducing (104) the images to a preestablished comparable standard; performing one or more tests on the digital images; generating ( 105) a result based on the outcome of the tests.

Description

METHOD AND SYSTEM FOR IDENTIFYING ROCKS Technical Field

The present invention relates to a method and a system for identifying rocks. Background Art

As is known, the earth's crust is composed of minerals and rocks. A mineral is a chemical compound that is found in nature and has a very specific composition and a clearly defined crystalline structure.

Over two thousand types of minerals are currently known. A rock is an aggregate of a plurality of minerals species in various proportions and therefore cannot be expressed with a chemical formula.

Rocks contain all 92 natural elements, variously combined together to form the various types of rock.

This gives rise to an extremely broad possibility of combinations: currently, in fact, there are over 30,000 classified rocks.

Rocks are classified according to their mineralogical configuration, structural configuration and others.

Since rocks are aggregates of minerals, a condition that is necessary for their recognition is the identification of the mineral species that they contain.

This, however, is not a sufficient condition: it is in fact necessary also to determine in which ratio the minerals are present with respect to each other both in terms of quantity and in terms of spatial relationships, contacts and mutual influences. In other words, the precise recognition of a rock requires studies which include a sequence of steps, including: identification of the number and type of minerals that are present, their quantitative ratios, determination of their spatial relationships, their shape, grain, mutual orientation and type of contacts, properties which as a whole define the type of rock. All these measurements can be performed in a laboratory on "thin sections", i.e., sections of rock that are prepared to be analyzed under a mineralogy microscope and can optionally be integrated with observations regarding the origin of the rock.

The means adopted for observation range from the human eye to the magnifying lens to the mineralogy microscope to the electron microscope and to X-ray methods.

Currently, a wide variety of methods and instruments for recognizing rocks, simultaneously or separately, are used.

The complexity of the investigation methods, the fact that they are performed manually, together with the vastness of the results that can be obtained, makes rock identification a specialist work.

Accordingly, the identification of a rock is always very laborious and the interpretation that is given is very often based on subjective criteria, and the quality of the results obtained depends substantially on the greater or lesser experience of the people involved. Disclosure of the Invention

The aim of the present invention is to overcome the limitations of the background art cited above, by proposing a new method and system for identifying rocks. Within this aim, an object of the present invention is to provide a method and a system for identifying rocks which is computerized and is capable of handling a large quantity of data and of comparing them objectively, outside of the subjective interpretation of the specialist, so as to ensure reliability of the obtained result. This aim, as well as these and other objects that will become better apparent hereinafter, are achieved by a method for identifying rocks, which comprises the steps of: obtaining at least one sample of the rock; generating one or more digital images of the sample; sending the digital images to a processing system; reducing the images to a preset comparable standard; performing one or more tests on the digital images; generating a result based on the outcome of the tests.

This aim and these and other objects are also achieved by a system for identifying a rock, which comprises: means for obtaining at least one sample of the rock; means for generating one or more digital images of the sample; means for sending the digital images to a processing system; means for reducing the images to a preset comparable standard; means for performing one or more tests on the digital images; and means for generating a result based on the outcome of the tests.

Conveniently, the generated digital images comprise one or more images of the surfaces of the rock and/or one or more images of the thin section of the sample.

Preferably, the tests conducted on the digital images comprise the performance of shape and color analyses and comparison with images contained in preset databases. Brief description of the drawings

Further characteristics and advantages of the present invention will become better apparent from the following detailed description thereof, given by way of non-limiting example and accompanied by the corresponding figures, wherein: Figure 1 is a block diagram relating to the system according to the present invention;

Figure 2 is a flowchart that illustrates the operation of the system according to the present invention. Ways of carrying out the Invention An exemplifying architecture of the system according to the present invention is summarized in the block diagram of Figure 1.

The diagram illustrates a sample of rock to be analyzed 1, one or more devices for generating digital images 2, one or more digital images 3, a processing system 4 and an output file 5. The architecture of the processing system comprises a mineral database 4', a rock database 4", and one or more analysis methods or tests

The mineral database contains all the fields necessary to identify a mineral; in addition to the name of the mineral and the ISE name, i.e., the international standard English name, it contains the characteristics of the mineral in digital writing, i.e., the set of characteristics that can be obtained from digital images, for example opacity, transparency, shape, dimensions, flaking, associations, relief, refractive indexes, color, pleochroism, birefringence and so forth. For each characteristic there are two fields, one for the value of the characteristic and one for the level of statistical reliability of the value.

The rock database contains all the elements needed to identify a rock; in addition to the name of the rock and the ISE name, it comprises a plurality of fields for each mineral identified in the rock: for example, a first field for the name of the mineral, a second field for the percentage in which the mineral is found in the rock, and a third field for the level of statistical reliability, and possibly other fields.

The operation of the system according to the invention is now described with reference to the flowchart of Figure 2. In step 101 , at least one rock sample to be analyzed is selected by a user. In step 102, a digital image 3 of the sample 1 is taken by means of the devices 2, which can be digital cameras, scanners, software packages, electron microscopes or a combination thereof, according to suitably set parameters (angle, zoom, ...). The number of images to be acquired, the type and the acquisition methods can be combined and are complementary and must be chosen depending on the discrimination difficulty, so as to obtain a number of images that is sufficient to identify all the provided parameters.

Since often it is not possible to acquire all the provided images, the system is capable of providing answers with the number of images that are present, regardless of their completeness, only reducing the reliability of the result.

In step 103, the images 3 thus obtained are sent to the processing system 4. Regardless of the type of acquisition, the images are standardized, in all the parameters that will then be used, by means of a program, which allows a homogeneous comparison with all the rest of the processing.

In step 104, the system performs a test to identify the type of rock according to what is indicated in one of the tests 4'", optionally by resorting to a comparison with the images contained in the databases 4' and 4", in which minerals and rocks are classified respectively.

The tests are aimed at identifying the parameters that allow identification of a rock, such as color, texture, structure and mineralogical composition. To obtain these parameters, the system uses the various types of analysis performed in step 101 , such as visual analysis, optical microscope analysis, and X-ray or electron microscope analysis.

The variability of the rocks and the amount of information that can be obtained are such that there is no objective limit to the data useful for identification and therefore to the tests to be performed; the limit is subjective and depends on the precision that one wishes to obtain and on the skill and experience of the operator.

The proposed method overcomes this human limitation; by utilizing the memory of a computer, which is infinite more capacious than a human memory, it is capable of taking into account all the available data simultaneously.

The method uses a series of algorithms that are capable of selecting elementary or composite characteristics which may or may not be present in every type of rock.

In particular, by comparing the data received from the images with the equivalents of the mineral database 4', the system identifies probabilistically the various minerals that are present in the rock and their percentage quantity; subsequent tests are performed until the set of tests provided for the given sample is completed.

At the end of the tests, and on the basis of their result, in step 105 the system outputs an indication of the type of rock that has been analyzed.

In particular, depending on the minerals that have been recognized, their percentage quantity, the level of likelihood of each individual component, and any other information obtained in the analysis step, a comparison with the database of the rocks 4" is performed for determining the type of rock, again in probabilistic terms.

The proposed method compares all the characteristics that it has been possible to identify with a homogeneous database and returns the result of probable identification of one or more types of rock that can be compatible with the entered data. The data need not be all available; their greater availability determines only a higher reliability of the results.

A characteristic of the system is further that it is open and makes it possible to add or vary new types of information if and when this information is available, with the aim of increasing reliability. In practice it has been found that the method and the system described achieve the intended aim and objects. In particular, it has been found that the method thus conceived makes it possible to overcome the qualitative limitations of the background art due to the fact that the investigation methods, previously performed manually and based on subjective interpretation, are now performed by the computing system; this makes it possible both to avoid errors due to inexperience and to handle a significantly larger amount of data than is manageable by the human operator, and therefore to reveal aspects that may be missed by a human operator. This method and this system further make it possible to have a more accurate estimate as to the statistical reliability of the results obtained and to increase reliability by increasing progressively the number of identification tests provided for a single sample: the group of tests is in fact not static, but each individual user can add identification elements. Clearly, numerous modifications will be clear and can be performed promptly by the person skilled in the art without abandoning the scope of the protection of the appended claims.

For example, it is obvious for the persons skilled in the art to vary the means for generating digital images: in a preferred embodiment, digital cameras on a microscope are used, but it is possible to use other types of devices, adapted to generate a digital image.

The operation for generating the digital images can be performed in a completely automatic manner or through a human operator who performs a series of standardized operations in a predefined order or also in a semiautomatic manner.

The scope of the claims must not be limited by the illustrations or by the preferred embodiments illustrated in the description as examples, but rather the claims must comprise all the characteristics of patentable novelty that reside within the present invention, including all the characteristics that would be treated as equivalents by the person skilled in the art.

The disclosures in Italian Patent Application No. TV2008A000155 from which this application claims priority are incorporated herein by reference.

Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

1. A method for identifying a rock, comprising the steps of:

- obtaining at least one sample of said rock;

- generating one or more digital images of said sample; — sending said digital images to a processing system;

- reducing said images to a preset comparable standard;

- performing one or more tests on said digital images;

- generating a result based on the outcome of said tests.

2. The method according to claim 1, wherein said step of generating one or more digital images of said sample comprises generating one or more images of the surfaces of the rock.

3. The method according to one or more of the preceding claims, wherein said step of generating one or more digital images of said sample comprises generating one or more images of the thin section of said sample.

4. The method according to one or more of the preceding claims, wherein said step of performing one or more tests on said digital images comprises performing shape and color analyses on said digital images.

5. The method according to one or more of the preceding claims, wherein said step of performing one or more tests on said digital images comprises comparing said images with preset databases.

6. The method according to claim 4, wherein said preset databases comprise a database which contains the types of rocks and a database which contains the types of minerals.

7. A system for identifying a rock, comprising: - means for obtaining at least one sample of said rock;

- means for generating one or more digital images of said sample;

- means for sending said digital images to a processing system;

- means for reducing said images to a preset comparable standard;

- means for performing one or more tests on said digital images; - means for generating a result based on the outcome of said tests.

8. The system according to claim 7, wherein said means for generating one or more digital images of said sample comprise means for generating one or more images of the surfaces of the rock.

9. The system according to one or more of the preceding claims, wherein said means for generating one or more digital images of said sample comprise means for generating one or more images of the thin section of said sample.

10. The system according to one or more of the preceding claims, wherein said means for performing one or more tests on said digital images comprise means for performing shape and color analyses on said digital images.

1 1. The system according to one or more of the preceding claims, wherein said means for performing one or more tests on said digital images comprise means for comparing said images with preset databases.