|Title of Invention||
METHOD FOR ASSESSING FABRIC SURFACE CHARACTERISTICS
|Abstract||The innovative fabric surface characterization method overcomes the difficulty in gathering the fiber information by performing image processing of the fabric image. The difficulty is because of the higher spatial frequency of the fabric image. In this invention air is passed over the abraded fabric parallel to the fabric surface, thus making the fibers to vibrate and motion analysis is done after video capturing to get to know the fabric surface nature. Thereby pilling nature and abrasion resistance of the fabric are evaluated with less time.|
|Full Text||4. DESCRIPTION
Method for assessing fabric surface characteristics
Field of invention
Field of invention relates to the textile fabric testing, and more particularly evaluation of fabric abrasion resistance, pilling nature and texture change caused by usage of fabric.
Background of the invention
Wear of fabric is influenced mainly by abrasion, pilling, i.e change in appearance of the fabric. Adverse appearance change causes abandoning the usage of the apparel before it physically damaged. The wear rating of the fabric is important to grade the fabric. Testing of abrasion and pilling are done in two steps. First step involves treatment of the fabric with abrasive material by which use is simulated. Thus generating pills on the fabric surface in the laboratory is time consuming operation. Second step involves manually comparing the treated fabric with the photograph supplied by standards institution like ASTM.
The accuracy of the result in the above method (Subjective evaluation) is questionable and results of different standard organizations are not the same. Ultimately testing and evaluation of the wear is done in consultation with the consumer. Fast and reliable method of wear assessment method is demanded in the field.
Objective assessment methods earlier proposed to increase the consumer confidence, based on image analysis and other techniques, are either time consuming or give inconsistent result for patterned and multicolored fabrics: Inconsistent results are mainly due to the higher spatial frequency of the fabric images. Adopting these techniques in retails and apparel industry, where large varieties of fabric are handled, is difficult.
Summary of the invention
The present invention overcomes the above-mentioned limitations and can be used to analyze the fabric surface and the pilling nature of a fabric with lower magnitude of error from causes like the color pattern of a fabric. The present invention also overcomes the difficulties in analyzing the textile fabric image to extract the surface fiber features like nature of the fibers forming the fuzz and the fibers, which will potentially form pills in due course when used or tested in the pilling tester. The reader in this field knows mechanics of the pilling and mathematical model of pilling developed by many scientists. The present invention is a fast reliable and objective method of evaluating the fabric for pilling, abrasion resistance and texture change caused by abrasion.
The first aspect of the invention involves abrading the fabric with abrasive material, passing air over the sample parallel to the surface of abraded fabric and using a motion picture camera to capture the pictures for extracting the fiber information by motion analysis. The sample holder holds the sample and the abrasion arrangement abrades the sample for analysis. Preferably the abrading arrangement includes a stepper motor and links to convert the rotary motion to linear motion to abrade the fabric against the abrasive material. In the air passing arrangement, the air chamber has an opening provided opposite the air entity for the air to exit as well as for abrasive head to enter and abrade the fabric. The top and two sides are made up of transparent material, like glass, for illumination and image capture and the fabric sample rests on the bottom of the Chamber.
The invention preferably uses a CCD camera directly communicate with the computer by IEEE 1394 link. Air valve, the abrasion head stepper motor and the camera are attached to the computer for controlling, video storage and video processing.
The air passage exerts force over the fiber. Thus the fibers long enough to bend by momentum; bends over the fabric surface and vibrate along the air stream. The vibration frequency and the length reflected in the motion pictures are based on many factors, among them the fiber stiffness, the length of the fiber and the force of the air are interest of this invention. The length of fatigue fibers and their proximity to each other is an indication of the fabric's potential for pilling. The frames forming the motion picture are analyzed with the help of a computer program to compute information about the fiber length and its distribution over the fabric surface, texture change and life of the fibers on abrasion. The life cycle of the fibers gives the abrasion resistance of the fabric. Information, thus obtained with large number of samples along with an expert's rating is used to develop fuzzy neural classifier for required single standard or for multiple standards available in the textile industry. This system is used to classify the fabric pilling, abrasion resistance and the surface texture in the fabric testing. The software developed also facilitates online training of the fuzzy neural classifier to accommodate new fabrics.
Brief description of the drawing
Fig-1. Illustrate preferred components of the present innovation. Fig-2 Illustrate steps for analyzing fabric surface characteristics Detailed description of the drawings
Fig-1 Illustrate s schematic of a preferred setup of the present invention
A CCD camera (1) is placed above the air chamber (2) and it focuses on the fabric sample holder (3) that is below the air chamber. The abrasion head (5) placed over the fabric sample is connected to stepper motor (4) and links to abrade the fabric through the front opening of the air chamber. The front opening is also an air exit. The air entry into the air chamber is through the regulator (8), on off value (7) and the distributor (6) are part of the air control. The air distributor has a perforated plate and a mesh to distribute the air evenly throughout the width of the sample. The necessary illumination arrangement is provided from one side of the air chamber through the glass wall. After firmly fixing the sample on the sample holder the testing routine is initiated by the user through the computer (9) with the help of software developed for this purpose. The Computer starts abrading the sample and captures images by the
CCD camera. It stores frames for predetermined number of seconds after every predetermined number of abrasion head movement. This operation repeats still the total number of abrasion and capturing setup is reached.
Fig-2 Illustrates the steps for analyzing fabric surface. The first step 21 is abrading the fabric sample with abrading mechanism (4) and (5).
The second step 22 is acquiring and storing picture frames in the computer while passing air through the chamber.
The third step 24 and 25 is getting the required information for computing and grading the fabric as explained in the summary of the invention. If'm' number of abrasive crosshead movement per cycle followed by image capturing for 'n' abrasion and image capturing cycles, Frames per second (FPS) of video is 'p' and capturing duration is 'q' seconds per cycle and size of video is MxN Pixels, then the feature extraction as follows:
Image may be defined as tow dimension function f(x,y), where JC and y are spatial coordinates. The amplitude of / is the intensity of the image at that point. Sequence of the images forms the motion picture or video. Video clip may be represented f(x,y,z) where z is the frame number in that sequence. Thus number of frames or discrete image per cycle will be p*q and z values form 0 to (p*q)-l. After the abrasion and video capture testing the resultant digital video sequence available may be represented as follows:
F,(x,y,z) = [ fi(0,0,0) fi(M-l,N-l,(p*q)-l)]
F„(x,y,z) = [ f„(0,0,0) fn(M-l,N-l,(p*q)-l)]
Where n is the number of abrasion followed by capturing cycle.
Each video clip is taken for edge detection of frames followed by motion segmentation. Sum of absolute difference (SAD) method gives motion energy and with motion energy threshold motion segmentation is performed. The resultant binary motion segmented image per cycle is analyzed for feature extraction of the required surface fiber information like number of fibers and its length. Thus n video clips give n binary images. By performing pixel to pixel Fast Fourier Transformation (FFT) of frames, the frequency of fiber vibration is estimated. The invention uses FFT, but any time domain to frequency domain transformation technique can also be used instead of FFT. Some new fibers will come out of fatigue and some will wear of when abrasion is continued. Processing 'n' motion segmented binary images abrasion resistance of the fabric can be estimated. Texture change is evaluated using fractal analysis and wavelet transformation techniques. These are powerful tools for texture description. Final step 26 is classifying the fabric with a grade by the neuro- fuzzy classifier developed with large number of sample with expert grades for single or more textile industry standard. The reader skilled in this art knows mathematics involved in texture analysis and neuro-fuzzy classification.
1. US Patent US5815198 - Vachtsevanos et al.
2. US Patent US5936665 - Vachtsevanos et al.
3. US Patent US6728593 -Huetal.
What I calim is:
1. A method of assessing fabric surface consist of
a fabric sample holder for holding the sample firmly, an abrasion arrangement to abrade the fabric; an air chamber and air connection with a control value; an video capturing device that can be directly connected to the computer for image transfer and control; and a computer system to control and acquire video from video capturing device, control abrasion arrangement, air passage and analyze the captured video for grading the fabric
2. The abrasion arrangement said in claim 1 consist of a motor controlled by computer driving circuit, cam arrangement to convert rotary motion into linear to-and-fro movement and a flat abrasive head facing the fabric to abrade the fabric surface.
3. The abrasive head said in claim 2 has provision to change abrasive material and loading weight of user choice and top of the head facing the camera has scaling marking for checking the camera setup like focus, field of vision, depth of field etc.
4. The said air chamber in claim 1 is made up of transparent material in top and sides for capturing image from top and provides lighting from side.
5. The method of analyzing the fabric surface nature from the video by motion analysis. The motion in the video is fiber vibration caused by the air passage parallel to the surface of the fabric.
6. The said grading of fabric in claim 1 is done comparing the processed information with the stored information in the computer by program.
7. The air entry in the air chamber said in claim 1 has distributor to distribute the air evenly throughout the width of the chamber.
|Indian Patent Application Number||37/CHE/2005|
|PG Journal Number||47/2013|
|Date of Filing||18-Jan-2005|
|Name of Patentee||YUVARAJ. D|
|Applicant Address||CHINNAMOOLAPPADI,PAPPANAICKENPATTI BO, SALEM DT|
|PCT International Classification Number||G01N33/36|
|PCT International Application Number||N/A|
|PCT International Filing date|