Most Cost Effective Enhancement for Poor Quality Security Camera

"Does erasing recording after say a 4 day storage increase the quality of the "deleted"image better than erasing it after 30 days?"

No. Both deleted images are exactly equal with a quality factor of zero.

As far as the camera goes, I am not aware of any software magic that will improve image quality. Even so, it is just putting lipstick on a pig.

You can try improving the lighting or relocate the camera, which is probably going to be the cheapest solution.

However, in the end you may just have to be resigned to replacing the camera with a better quality unit.

There is software that can be used to effectively enhance a "still" from your camera. However, it would cost much more than a high quality camera.

Some cameras have replaceable lenses, which can improve quality at a specific distance.

There are currently cameras manufactured in China which cost under $100.00 USD, and compare in picture quality to $500.00 + cameras.

GIMP (the name is capitalized) does exactly that - still-image enhancement - for free. GIMP is basically an Open Source 'Photoshop' and is quite powerful. Can't beat the price. Available for Windows, Linux and IOS.

To the OP: Speaking of image-enhancement (both stills and video) you cannot extract more information from an image/video than is already there, unlike CSI and these other cyberdrama shows which somehow manage to extract a license-plate number from just one pixel.

My advice is to get a better camera.

Most cameras marketed today, as night vision cameras, are normal cameras, with some infrared LED's. They only light the area a few feet from the camera. If the image is good in daylight, then proper lighting is the only answer. Check the spec sheet of the camera, lumens will indicate how sensitive it is.

The more sensitive it is= more $$$! Proper lighting is the best choice, and your dog will thank you for the night light.

You can buy high-intensity IR floodlights, some of which can illuminate your property and beyond. The one I used made objects 400 feet away easily visible to our security cameras. Quite a few distributors; this one, for example:

http://www.nightvisionexperts.com/ultra-covert.html

If you've got the budget you can go whole-hog with FLIR, deep-IR security cameras which do not require a light source. These cameras image body heat and operate at the much longer wavelength of around 10 microns:

http://www.flir.com/cs/emea/en/view/?id=41859

It has been quite a while since I studied camera system design, without cracking open my old binders on the subject, you can try these tradeoffs:

switching to black and white instead of color, this will work fine in court

lower your frame rate, for example 30fps to 16fps but not much slower than this.

Add infrared lighting for night conditions and shaded areas.

reposition camera to avoid direct or reflected lighting or switch to diffuse lighting if possible. Alternatively, the camera may have masking features built in. (Add lighting behind the camera pointing toward your field of view as well.)

a wide angle lens may cover more area but sacrifices quality, and obscures details necessary for conviction if used in court. That's why supermarkets usually dedicate at least 2 cameras per aisle with a more narrow field of view and close up detail at egress points and check out lanes. (You will notice their lighting is consistent as well)

Know your camera inside and out, look it up online, check the specs. and learn each feature. There should be a sticker or nameplate somewhere with serial no. etc…

Bribe an associate or friend who is good at photography to come over and check out your cameras. Very often, they can spot what limitations you have and show you what to do about it. Be sure to have your specs ready to answer questions so you don't waste their time. [p/]

Purchase cameras with CCD sensors and over 600 TV lines.

Most lower end cameras utilize CMOS and are generally 380 TV lines. Good cameras make all the difference in the world. Priced around $90 ea, (less lense) (plus shipping for the better quality)

South Korean cameras and DVR seem to be better quality than Chinese. e-Bay

Hope this helps.