In 1910, the apparel industries began size labeling to make and sell ready-to-wear clothing. A size labeling signifies one set of garment size in a particular sizing / labeling system made to match the body sizes of most individuals in a population.
As the anthropometric data on which the ready-to-wear sizing system was based was obsolete and off-the-track, the clothing does not perfectly match the present population. Many reports showed that around 50 per cent of the women surveyed are not satisfied with the perfect fitting of clothes in the present sizing system.
Making garments that match with customers' needs requires information about the individuals' body size and shape. Technology utilized to rapidly modify mass-market products (e.g. apparel) is known as mass customization and agile manufacturing. This increases customer satisfaction and decreases inventory costs. In recent times, mass customization has turn out to be an effective tool for the U.S. apparel industry to compete in the global market.
Apparel mass customization needs automation in at least three ways: body measurement, pattern design and fabric cutting.
Earlier there were many systems available for measuring body for apparel with 2-D scanning system. Though, there are two major obstacles that avoid those systems from being widely used by the apparel industry. Firstly, the prices of the body-scanning systems are very high as compared to the apparel industry. Secondly, the systems neither are well connected with apparel CAD systems, nor do they give designing functions that allow a customer to design or choose a garment that fits his/her body. The customer will have to depend on a professional designer to employ the body data for alternating pattern pieces to make a personalized garment. At present, the apparel CAD systems used by designers are 2D based pattern design systems that do not cover ways to visualize garments in 3D graphics. The design effects can be analyzed only after the garment is actually produced. This non-interactive attempt limits designers' creativity. Hence, there is still a requirement for a cheaper and feasible system that can do body scans, body modeling and designing of virtual garments in an incorporated way to speed up the process of apparel customization.
But nowadays, body-scanning technology turns out as a remarkable research and development field around the world, and a few systems are available in the market with 3-D scanning system. This body scanning and 3D garment design technology is objected for various apparel businesses. This system now can offer rapid, non-contact scanning of a whole or partial body to receive size information necessary for garments; make customized body forms on the computer screen as models for apparel design. A body form stands for the scanned body by having a many point measurements of the body, and can be applied for analyzing the style and matching of a garment being made.
The current internet era has also led to the emergence of new 3-D body measurement tech�nologies that permit consumers the facility to store their body measurements in the computer. They can then use designer software to electronically tailor designer clothes at an affordable cost in the comfort of their own home. Such body measure�ment technologies can decrease long hours of shopping, various unknowns when buying clothing online and considerably decrease the number of clothing returns.
Body scanning is the latest technology that helps to shift the spotlight of apparel production from large quantities of cookie-�cutter clothes, to one-of-a-kind products with individualized sizing and designing features.
Three dimensional body scanning structures
Generally, three-�dimensional body scanners capture the outer surface of the human body by using optical techniques, in combination with light sensitive devices, without any physical contact with the body. The subject normally wears form-fitting briefs or shorts during the process.
Body scanning systems contain one or more light sources, one or more vision or capturing devices, software or computer systems and monitor screens to see the data capturing methods. The basic body scanning devices are laser and light. Three-�dimensional scanning systems can be seen in several areas like statistical analysis, modeling, animation, medicine, anthropo�metries and apparel. Most of these devices are available in Japan, the United Kingdom, Germany, France and the United States.
The scanning system uses the multi-line triangulation method to receive speedy surface data of a body, and gives perfect body measurements, many of which are not measurable with traditional devices.
Body scanner
The three-dimensional body scanner is a device that captures information about the surface of the body by using multiple laser or white lights and CCD (Charge Coupled Device) cameras. Through elec�tronic circuitry and a micro�processor the data is unloaded, which is then processed, saved as a file, and seen as a three-dimensional image on a computer monitor. This image is full, dimensionally accurate replica of the scanned object that can be seen and rotated, and can be measured on the computer screen. Scanners vary in their number of cameras, footprint and light source, and in the classiness of the software they apply use for visualizing and testing.
Computer-aided design is a broad term which ranges from tasks in the design of products, buildings, landscapes, etc. In the apparel industry, CAD systems are applied for artistic representation of prod�ucts, many technical aspects such as pattern making (both standard graded patterns and custom patterns) and file storage.
The system is made up of a PC computer, a control circuit box, and a 5 x 8 x 8 (WxLxH) ft3 dark booth (Figure 1), in that two linear stages are mounted on the front and back sides of a person.
Each stage consists of a multiple laser line projector (eye-safe) and a CCD camera to scan the whole body when the stage goes upward. This scanning unit is connected with the control box managed by the computer to perform triangulation measurements. All scanning and measuring instructions are transmitted from the PC through the parallel port to the control box, which handles the scanning units to perfect positions, shifts to the laser projectors and then sets off the cameras to receive images. The scanning units may stop 5-6 times to ensure the whole body to be scanned.
The measurement is based on a triangulation algorithm. A simple geometry of an active laser triangulation is shown in (Figure 2). The CCD camera is connected with the Z-axis with the centre of the lens positioned at (0, 0, 0). At a baseline distance (b) to the left of the camera (along the nega�tive x-axis) is a multi-line laser generator projecting a beam of laser lines at an angle � with the x-axis baseline. The point (x, y. z) is then framed into the digitized image at the pixel (u, v) so uz = xf and vz = yf by similar triangles where f is the focal length of the camera in pixels. The calculated magnitude (u, v, �) are applied to figure out the (x, y, z) co-ordinates.
To estimate the coordinates (x, y, z) of the body, the laser lines in the original image must be outlined and the projection angle for each line must be calculated. Figure 3a illustrates one of the grabbed images that include laser lines with various projection angles. Considered in a given arrangement, the projection angle of the midst laser line and the inter-beam angle are both identified. After a line is sketched, the coordinate of all the pixels on the line (u, v) and the projection angle � can be measured. Hence, their corresponding 3D (x, y, z) coordinated can be measured by applying the above equation. Though, the projected laser lines on the body are not uniform in its intensity. At small changes, laser lines show indistinct and even broken lines. To overcome this problem, many image-processing techniques like adaptive thresholding and curve fitting are applied to manage complex situations of broken lines. Figures 3a and 3b illustrate the original lines and the traced lines of an upper body.
When the traced lines of all the confined images are transformed into the (x, y, z) space and overplayed on a new image based on their comparative scanning positions, the lines covering a whole body can be received.
After scanning both front and back body surfaces, the two im�ages can be combined and body dimensions can be calculated on the 3D data.
There are many measurement techniques that are applied for apparel design. These measurements are connected with many points of the body. The type of a body measurement can be the distance or angle between two points (eg: yoke and shoulder slope), the length of a surface curve (e.g. crotch), and the circum�ference of the body at a point (e.g. bust). The measurement can be used to make a body-form or directly be transmitted to a 2-D CAD system for pattern adjustment. It takes three basic steps to extract perfect body measurements from the 3-D body data:
a. Find body points such as waist, chest and neck. According to the features of body, most points can be automatically analyzed. Since human body shapes differ considerably, manual involvement may also be required to adjust points for perfect measurements.
b. Sort out the data by applying relevant techniques, such as B-spline curves to smooth and connect points of a cross-section at one point or a space curve between two points.
c. Calculate measurements like circum�ference, distance, angle, etc.
Body modeling
3-D body modeling is a method to create a body form on the computer screen by using a set of significant measurements from a scanned body. A body form, also called dress form, acts as a personalized model for style manipulation and fitting modification. A computer made body form permits a designer to completely rotate and zoom the form for seeing and determining the body shape. A human body looks like a fairly complex surface. To make a body form, a body needs to be divided into a number of comparatively simple sub-surfaces that can be approximated at surface functions. For example, the upper part of human body, torso, can be separated into seven parts: neck, shoulder, chest above waist, abdomen, etc.
Conclusion
There are uses of body scan data outside the apparel industry too. The airline, automobile and tractor industries have used scan data to make seats that are optimized for the highest number of body types. The entertainment industry has used scans to make animations, most lately of sports stars for video games. Health club have used body scan technology to measure the effects of workout programs by using the 'before' and 'after' comparisons. The use of body scanners is in its development stage. Many prospective applications are yet to be discovered.
At present, another use of body scanning is under development which permits customers to 'Try on' garments in a virtual environment. An individual's scan is visualized on a computer while clothing of a variety of sizes is placed over (in 3-D) on a rotatable image. The computer application highlights areas of good and bad fit, assisting the user to choose the most suitable product.
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