Digital Camera Maintenance

Caring for the expensive digital cameras and Camcorders is easy enough if you have a steady hand and armed with the right knowledge and the right tools.

1. Keep Your Digital Camera Clean:

“ A Stitch in time saves nine” – “ An ounce of precaution is worth a pound of cure ” If you observe the basic precaution of keeping your digital camera clean on the inside and outside, you will have less problem in their maintenance. Invest in proper camera bag and at the minimum a blower brush. Never wipe the lens with your fingers or any cloth. The lens will have a chemical coating to protect against surface reflections. It is this coating which enhances the image contrast by reducing the reflections from the surface of the lens element. This protective coating is susceptible to grime and the natural oil in your fingers.

Use the blower brush with new bristles to clean the dust away from the lens. If you have a digital SLR camera, you could start with a Skylight filter to protect the expensive the lens. If your lens has picked up enough dust, you could clean it with a proprietary camera lens cleaning liquid with a micro fiber cloth. This cloth has extremely fine fibers closely woven so that it cleans well without leaving any trace.

Clean the body with a clean dry cloth. For stubborn grime, clean the outer parts of the camera with isopropyl alcohol dipped cloth. It is a good idea to clean the electrical contacts (if any) with a paper card. Do not use any organic solvents to clean the body or lens.

For general routine cleaning the sensors of the digital SLR, you would need the following:

a. A pair of rock steady hands

b. Fresh batteries or fully charged batteries

c. Set your camera to manual and B mode.

d. Set the camera on a foam pad on the desk illuminated with a bright lamp

e. Sensor Cleaning kit ( if your camera really is in such a bad shape)

f. magnifying Glass (if you are not a spring chicken)

In case the camera times out and closes the shutter, you might end up damaging the mirror or the shutter or in the worst case all the above in addition to the sensor. If you are not sure, you will be better off to attend to this professionally.

Blow the dust with a blower brush aiming the jet of air in such a way that the dust is blown off the innards. Check the sensor with a magnifying glass for any trace of dust. With a fine bristled brush from the kit, wipe away the dust if any. Reassemble.

Digital Camera Maintenance - pitfalls

The Photo illustration adjacent here probably shows all the elements that can hurt a digital camera – sand, dust, fur and the electrostatic charge from stroking a cat.

2. Storing Digital Camera: Always store your camera gear in an air tight cover with silica gel bags. There are indicator types of silica gel bags which change color when fully doused with moisture. They can be kept in a warm oven to dispel the moisture and they can be ready. But the fact remains that they are cheap and can be discarded. Remove the batteries when not in use for more than a week. Store the camera in a separate air tight cover and the rest of the accessories in another cover. Your camera bag should include padded bottom to protect the camera from occasional knocks. Don’t count on the padded interior to protect the gear from a fall. Charge the rechargeable batteries every couple of months. All nickel cadmium batteries have a “memory effect” which will tend to reduce the available capacity. Metal Hydride batteries and Lithium ion batteries have no such memory effect.

3. Memory Card Maintenance:

These days memory cards come in high capacities – a few Giga bytes at very reasonable rates. Still it pays to be careful with them as a sudden failure can lead to complete loss of precious images you have shot. Always carry extra memory cards. Avoid wiping a few images every time. It is far better to wipe a batch after downloading to your hard drive. Avoid handling the contact surface. When connected to the computer, use standard PC precautions waiting for the signal like “safely remove hardware” before you remove the card.

Shoot a visiting card or a self addressed label as the first shot in the memory card. In case the camera is misplaced, the finder may return the camera.

You will have noticed that if your hard drive is almost filled to its capacity, it slows down the performance of your computer. Same way leave some space in the memory card – another reason to carry additional memory cards.

OCR with Webcam

OCR with Ubiquitous Webcam

Optical Character Recognition (OCR) technology has matured to include digital image processing and with the kind of processing power available in the average Personal computer, it should come as no surprise that in these days the accuracy of the OCR exceeds 99 %.

Typically most software commercial or free would require that you use a TWAIN compliant scanner to capture the image you want to use for converting to editable text. For best results this might be the only way as you need to present the best possible image for the OCR software to work upon. You will need to acquire black and white or grayscale image as color information would confound the OCR process.

In case your software has any issues working with your scanner, you can still save the scanned image in a TIFF (Tagged Image File Format) format and invoke the OCR software with this TIFF file. Most image editing tools will have no problem converting the images to this TIFF format.

When you are in the office, it would not be an issue to use the services of a desktop scanner to convert the magazine page or newspaper page to electronic format. Many a time you would see when you are traveling – a magazine article or a newspaper page which would be ideal to illustrate your stand. Only thing that would stop you is the lack of accessibility to a desktop scanner. You don’t have to wring your hand in despair anymore.

Your Laptop may already be equipped to take care of not only the means of capturing the newspaper/magazine page, but also the requisite software to convert the acquired image to editable text format. I wanted to do a bit of test in this line and this is what I found out.

I have a Laptop with barebones software installed and not too many techno wiz attachments. The notebook is equipped with a 1.3 mega pixel (extrapolated resolution) Web camera and MS Office installed amongst other things. A typical scenario.

I used the webcam to “capture” this image displayed here from an old magazine. You can see from the faded sepia toned color that the magazine must have been sitting at the shelf for ages. Again the choice of this torn page was deliberate to demonstrate that if we can get any decent result from such a faded magazine page, you should get far better results with a better recent subject.

OCR with Webcam

Now you need an OCR software to complete the conversion process. You need to look no further than the standard MS office software suite for this.

Click on All Programs – > Microsoft Office – > Microsoft Office Tools – > Microsoft Document Imaging

You will have a “free” OCR software here and it will take the above image acquired from the Webcam. Just click on Page from the top menu and select the and you will get the following page:

OCR software

Click on Tools – > Recognize Text using OCR and it will have converted the image into editable text ready to be ported to MS Word. Click again on Tools – > Send Text to Word and your MS Word will fire up with the converted text.

This is what mine did at the end of the exercise:

A T one tirn, p!opIe
did&t daw to svar
t3eMhe’r—go1d’ look. But
rw dlnw gold teamed
with pLItinuTn or white
ldz so in, and Ioks so
good, u wonder why it
took u so long. At InterCold. there i a .triking rngi. of unfussy, elcg.mt jcseItery — rings. earrin. chair . and pvidant in theit very f fordable Career Carals range. embellished with diamond and pearls. Prices begin at R 3.)OO. And for tho thinking of tying the knot, it you haven’t chcn our wedding nng yet, take a peek at the ‘Rings for E1rnitv’ range. You’ll go mad trying to make up your mind…

Not too good – You would say. But you had supplied a color image in the first place. With a bit of image manipulation and a grayscale image the eventual outcome is almost 85 % accurate. Not bad for a basic web cam based OCR.

Network Surveillance Cameras

Linux video camera Security II

A few months back we have dwelled on using a web camera to augment the security of our premises. We have talked about using the ubiquitous web camera to double up as a security camera. But there are several drawbacks in using a standard web camera for security applications:

It has a limited angle of vision – Originally a web camera is designed to have a 45 degree of view. It comes with a pre focused lens and the lens quality is not enough to provide adequate resolution for security purposes.

Even with a higher resolution web camera which provides 2 mega pixel resolution, the required resolution is still limited with the kind of illumination available at a typical office environment.

The illumination level required to provide sufficient detail for security is not enough with ordinary run-of-the-mill web cameras. So we will look at other options – Network Surveillance Cameras (network cameras and IP cameras) in this installment.

In this category we have a bewildering array of cameras available with many connectivity options – Wifi, built-in Network card with/without Image compression software to obviate the need for one at your server end. Many come equipped with optical zoom and Pan/Tilt head assembly. The camera can be controlled through a control panel in the built-in server.

As these cameras are designed for security applications, they have low light sensitivity – often as low as 0.05 lux and coupled with optical zoom in the range of 10 X – you have a decent security camera that can “identify” the license plate number of a visitor’s car in the driveway.

One thing we have noticed in our camera is that the camera lens soon picks up enough dust (possibly owing to the power supply providing a positive electro static charge) which results in a grainy image. So for best results, keep your camera lens/assemblies scrupulously clean.

We also provided a bank of Infra Red LEDs to provide additional illumination wherever required (indoors). Needless to say, almost all cameras we tested contained enough sensitivity in the infra red region. In case you have a doubt, use any infra-red remote control to shine at the camera. You should see a line of white light being emitted from the remote control.

Some web cameras deliberately use an infra-red filter between the pickup device and the lens.

But as we have decided to use specifically crafted Surveillance Cameras, this would not be an issue.

Network Surveillance Cameras

As this is a Hands-on approach to the installation and maintenance of Network Surveillance Cameras, we will start with the selection of cameras first. For outdoor surveillance it would be prudent to go in for a robust enclosure to house the camera and in these days, there are quite a number of manufacturers who build specially designed metal enclosures with industry grade mounting brackets.

Compared with a traditional type CCTV camera installation, Network type camera installation offers several advantages:

1 Cost – Compared with low loss video type coaxial cables, Data networking cables are cheaper.

2. CCTV cameras which provide CVBS (Composite Video with Blanking Signal) output need to have a short run to the distribution amplifier or monitor to avoid high frequency signal loss. All analog systems suffer from this cable distance issues Network cameras use a data encoding system to send binary data across a shared network.

3. Advanced Functionality is easy to implement using software in the case of Network cameras while you need expensive dedicated hardware for the traditional CCTV network.

4. Easy scalability – you can add as many cameras as you require – limited only by the software. You can add individual units as you go.

5. Remote Monitoring and ease of storage: With dropping prices of hard disks and vast quantities of storage space available, you can save to disk all of the outputs from the cameras for later analysis. With suitable authentication, you can monitor your office half way across the globe through internet.