Food is any substance consumed to provide nutritional support and energy to an organism. It can be raw, processed, or formulated and is consumed orally for growth, health, or pleasure. Food is mainly composed of water, lipids, proteins, and carbohydrates.

Every country had its own Food culture and were restricted to countries or even regions inside a country. With Globalization this food culture has spread across the globe and one can get any country food ( be it cooked or to be cooked or fruits, vegetables, or process or unprocessed etc..) in any part of the globe. This spread of food culture has also prompted for QUALITY and STORAGE done or maintained through technology and also inspected through Technology.

There are strict regulations followed across the globe by different countries and worldwide organizations on Food quality, control and safety to consumers.

Unlike before 50 years or so, now machines are used in every place starting from Agriculture to sorting to packing to storage to delivery. In every place, there is a need to follow the standards set for quality and safety. To ensure these standards of quality and safety, Food companies need proper inspection system. Machine Vision can play a major role here.

Broadly we can segment the Vision applications into these categories:

• Agriculture – cultivation, vegetation related inspection – includes pest control, weed control, land and mineral assessment – cameras ( of varied sensors like IR, Visible, color, Multi Spectral, Hyper spectral) and vision systems can play an important role in this including implementation on Drones and harvest or seeding equipment.
• Sorting and Grading – Grains, Fruits, vegetables, Nuts, Milk and other liquids ( as I am a Vegetarian, guess missing other items like Sea Food, meat etc.,) . These sorting and grading systems play an important role and Machine Vision cameras with systems are needed to achieve the task with precision.
• Package and Content Inspection: Any food product made are to be packaged and filled in packages according to the limits , sealed properly (Cap etc.,) and also avoid foreign particles or defective particles inside the container. Dimensions of packaging may be a caron or a tetra pack or a glass bottle needs inspection. Cameras with visible, SWIR sensors in high speeds and effective optics and lighting achieves these tasks.
• Label Inspection: Products made are identified outside only by seeing the labels pasted on the packages. All vital information about the product is printed on the labels. Proper labelling can be ensured through Machine Vision cameras – where Line Scan cameras while printing the labels and also after pasted on packages.
• Food contamination: Packed foods are transported or kept in storage ( cold or so as needed) and may get contaminated. This section can also be classified under foreign object detection on food, but I have classified it here as these contaminations have to be inspected not at production end but at receiving end on sealed products. Hence SWIR and XRAY may have to be used in these contamination detections. There are food safety regulations on using XRAYs too.

With these categories of Food Inspection, let us get into some of the Machine Vision aspects including sensor technology to understand the usage of the same in the Food Inspection projects.

Components of Machine Vision System towards Food Inspection listed above:

• Area Scan Visible range cameras: These cameras are available in different resolutions from VGA to 150MP in different Frame rates from 25fps to few hundred frames – depending on the output communication that includes Port based – GigE (1, 5, 10 and 25 GigE), USB, Frame grabber based Camera Link, CXP, CLHS and in formats like Mono, RGB Color, Bayer Color etc., According to the Field of View, Minimum Defect or smallest point to be resolved, speed (if in motion), analysis required ( color or mono ), suitable cameras and optics can be picked for the project. Due to GenIcam and standards of camera followed it is now easy to use these cameras with any software environment and processing tools.
• Line Scan Cameras: In applications that demand speed or analyze the products in motion or with greater accuracy, Line Scan cameras can be used. One can visit our blog in our web site onlsol.com to know more on Line Scan technology and working. Line Scan as sensors or cameras are used in Sorting, Print/label inspection, defect analysis etc… These cameras are also available in Port Based and Frame grabber based outputs.
• Specialized Cameras: We can categorize SWIR, MWIR, LWIR, NEAR IR, XRAY, Hyper Spectral, Multi Spectral, X RAY cameras in this. These cameras may come with standard interfaces like explained above but it needs specialized optics and software to handle the data received for processing. For example, Hyper Spectral cameras give out Data cubes to be handled to differentiate the spectrums. A blog in our web site onlsol.com covers more info on this. X RAY unlike dealing with reflection of light in other cameras need a proper source which comes under lot of radiation regulations. These specialized cameras or sensors or detectors can be in Line Scan or Area Scan.
• Lens and Optics: This would be the key to get proper images. Lenses are available for different spectrums ( with coatings to allow specific spectrum of light), in different mounts to suit sensor sizes on cameras, specific to IR region, in different focal lengths as fixed or zoom. Liquid lenses provide the additional benefit of autofocus of objects fixed between limits. Tunable lenses are also now available to achieve autofocus operations. It should be noted that without proper lens the task of analysis would become more difficult and at times impossible. While budgeting the lens may take a larger share than cameras in some cases. Our web site onlsol.com has blogs on Lens and Liquid lenses etc…
• LIGHTING: As like lenses, lighting to illuminate objects to reflect as needed for the project is important. Lightings are available in different spectrum and heats. For example, you can have a white light ( normally used in color analysis) in different Kelvins categorizing as Cool, Neutral etc… This is very important as the products dealt are Food and may get affected by different temperatures of Light. To see through something in a packet, SWIR can be used with specific wave lengths of illumination. Lightings are available in different shapes, colors, wave lengths, sizes as Bright Field, Dark Field etc… Lightings accompany cameras in the Vision Systems to perform the task and hence lights suitable for area scan or line scan to be chosen for precise working.
• Other accessories: Suitable Port cards and Frame grabbers to grab images from different types of cameras, Filters ( optical filters) , Diffusers, Polarizers, compatible hardware like PCs, Embedded systems, controls etc., are to be chosen properly.
• Software: Software essentially is the hand shaker with End user or customer to process or deliver the reports, program the defects, or control other following devices. Software for developers is available in SDK formats with every camera and accessory supporting different Operating Systems, Programming languages and as GUI platform also. Software for end user is bit tricky as these food products and its allied tasks would keep changing and end users may have lot of needs with expansion in mind while going for such vision systems. It needs an in-depth study of the needs. Many projects can be done with proper hardware and conventional Image processing and Machine Vision algorithms. Few may need Artificial Intelligence (deep learning) algorithms or the combination of both conventional and AI.

Our web site www.onlsol.com under support has a Pre-sale area where we have suitable forms to be filled by customers to express their need on these kinds of Food Inspection Systems. The same forms are also available as APP for Androids called MACHINE VISION ASSISTANT and can be downloaded from Google Play Store.

Online Solutions (imaging) Pvt. Ltd., Chennai India with 3 decades of experience in the field of Vision distributes different products related to the above from worlds renowned companies like Teledyne DALSA, Pixelink, ADCIS, Navitar, Midopt and also resell many other company products towards giving total solution for development of Food Inspection applications.

Compiled and written by S.SUKUMAR – DIRECTOR – PROJECTS LinkedIn

Note:

This blog may contain some compilation of different related Contents and Images from general purpose web sites or from the web site of the companies represented by us in India. Any one finding any objection to the use of the same can report to us at [email protected] and we shall make corrections as per legal requirements. This blog is more of informative purposes only.