Showing posts with label Pixel Resolution. Show all posts
Showing posts with label Pixel Resolution. Show all posts

Sunday, November 5, 2017

CCTV Recording Resolution

CCTV Recording Resolution

Digital Video Recorders (DVR) and Network Video Recorders (NVR) are the heart of every security camera system. Customers often ask us about recording quality from CCTV cameras, things can seem relatively straightforward: you’ll need a DVR/NVR that can handle as many channels as you have cameras, and the more hard drive space you have for archiving all that video, the better. Naturally a customer wants to know how clear the video resolution will be from a system before making a purchase decision. Final outcome of your captured footage, 


Recording resolution is the number of pixels (dots) used to create an image. Higher resolutions use more pixels to create an image. This means that greater amounts of detail can be expressed in the image, but larger files sizes and a greater amount of storage (i.e. Hard drive space) are required to save the images or video. See the example below.

The resolution is increasing from left to right
Recording resolution is measured as the number of horizontal pixels by the number of vertical pixels (Width x Height). The following table shows some common recording resolutions.
Name
Width (Horizontal Pixels)
Height (Vertical Pixels)
Total Number of Pixels
Recommended Camera Equipment
CIF
360
240
86,400
320TVL, 400TVL, 420TVL, 480TVL,
2CIF
720
240
172,800
420TVL, 480TVL, 540TVL
VGA
640
480
307,200
540TVL, 600TVL, 1MP
D1
720
480
345,600
600TVL, 650TVL, 700TVL, 800TVL
720p
1,280
720
921,600
720p, 1.3MP
QVGA
1280
960
1228,800
960p, 1.3MP
1080p
1,920
1,080
2,073,600
1080p, 2.1MP
3MP
2048
1536
3145,728
3MP
5MP
2560
1920
4915,200
5MP
6MP
3032
2008
6088,256
6MP
8MP
3264
2448
7990,272
8MP

Notice the increase in the total number of pixels as the resolution increases. Because the total number of pixels is determined by the number of horizontal pixels times the number of vertical pixels, if both horizontal and vertical pixels are doubled, the total number of pixels increases by a factor of 4. This means that the amount of hard drive space needed to store an image or a given duration of video will also increase by a factor of 4 (given factors such as the frame rate remain equal). It is recommended to try different configurations on your system to balance image quality against the amount of storage space available.

Now based on the capabilities of your DVR you may choose to record in a certain picture resolution based on certain requirements unbeknownst to anyone but you.

I have seen a lot of misconceptions of the newly introduced 960H. Amongst the confusion, I have seen a statement along the lines of 960H provides you a 960x480 and/or 720x480 picture; as well that it improves the picture of any camera fitted with a 960H sensor via your current DVR. This is a BIG misconstrued myth. Submitted for your approval are the facts of 960H
1.   960H is NOT a megapixel resolution
2.   960H sizes are NOT 960x480 or 720 x 480 formats
3.   Cameras equipped with 960H alone, will NOT provide you with a refined captured footage of 960x480

The graphic below shows a comparison of the resolutions listed if each pixel takes up the same amount of space.


F.Y.I For all footage across every system, after video is recorded it can be magnified (zoomed in) but only digitally either through a computer or the DVR (if capable). That means, the individual pixels that create the picture can be made bigger. However, for analog footage, there will be no real advantage at detail due to the low-res of pixels.

Saturday, June 6, 2015

Megapixels Resolution in PPI

Megapixels Resolution in PPI

Now a days IP Camera markets going to use 7MP, 10MP, 16MP resolution for Better background information (photo quality).
The first things to understand is that in digital imaging, the only thing that really counts about a file is how many pixels are in a file. Terms like megapixels, DPI and file sizes in megabytes only confuse the issue. In the end, all digital images are simply X pixels by Y pixels big (by Z bits of colour data but we can ignore that for now)

Pixels Per Inch is the key term. It is a description of the logical number of pixels from your original image (X pixels by Y pixels, remember) that will be used to tell the printer to print one inch on paper. Assuming a sharp original shot with good technique (see resolution discussion below), the higher the PPI, the better the quality print you can achieve - this is testably true even well beyond most claims of 360 PPI being the most you need ... 600 PPI images can easily be seen to be much sharper again if this data is available at good quality from the original file).

Here's why:
1. A megapixel is 1 million pixels. It's an area measurement like square feet.
2. A typical 8 megapixel camera produces images that are 3266 x 2450* pixels.
If you multiply 3266 by 2450, you get 8,001,700 or 8 million pixels.
3.  To find the largest photo quality image you can print, simply divide each dimension by 300:
3266 / 300 = 10.89 inches
2450 / 300 = 8.17 inches

4.  If you are not publishing your images in a book or magazine, and you're just making prints for yourself or your friends, you can "cheat". Good quality inkjet printers can make a nice looking print at 250 or 200ppi. At 200ppi, the maximum print size becomes:
3266 / 200 = 16.33 inches
2450 / 200 = 12.25 inches

Megapixels vs. Maximum Print Size Chart

Megapixels
Pixel Resolution*
Print Size @ 300ppi
Print size @ 200ppi
Print size @ 150ppi**
3
2048 x 1536
6.82" x 5.12"
10.24" x 7.68"
13.65" x 10.24"
4
2464 x 1632
8.21" x 5.44"
12.32" x 8.16"
16.42" x 10.88"
6
3008 x 2000
10.02" x 6.67"
15.04" x 10.00"
20.05" x 13.34"
8
3264 x 2448
10.88" x 8.16"
16.32" x 12.24"
21.76" x 16.32"
10
3872 x 2592
12.91" x 8.64"
19.36" x 12.96"
25.81" x 17.28"
12
4290 x 2800
14.30" x 9.34"
21.45" x 14.00"
28.60" x 18.67"
16
4920 x 3264
16.40" x 10.88"
24.60" x 16.32"
32.80" x 21.76"
36, Nikon D800
7360 x 4912
24.53" x 16.37"
36.80" x 24.56"
49.06" x 32.74"


*Typical Resolution. Actual pixel dimensions vary from camera to camera.
**At 150ppi, printed images will have visible pixels and details will look "fuzzy".