HD refers to cameras with a standardized resolution of p or p. The numbers and refer to the horizontal resolution. Therefore, p HD camera resolution provides images that are x pixels that adds up to , pixels, which means a p HD camera is not technically a megapixel camera , and p HD cameras provide x pixel resolution, or 2. The HD video format also uses an aspect ratio of rather than or , and the frame rate is standardized at 60, 50, 30 or 25 frames per second the fps depends on your TV.
According to a report by TechNavio Insights, IP surveillance is poised for significant growth among end-users and large organizations. The benefits of software-driven functionality and the control, scalability and broad availability of video are often listed as factors contributing to this growth. However, among the biggest performance features of IP surveillance is the ability to provide a broad range of video resolutions.
With H. The first is because some consumers can easily identify with a product that has its resolution described in megapixels as opposed to HD resolution and vice versa. The other reason for the two different descriptions for video resolution is a separate measurement: the aspect ratio. The aspect ratio is a common reason why a webcam is either described as HD or in terms of the number of megapixels.
HD webcams, or webcams that are described in terms of p or p resolution, have an aspect ratio of , which is a widescreen view. When it comes to a webcam that has a 'normal' , like the sensor in a DSLR camera aspect ratio, you are more likely to see the resolution listed in terms of megapixels. When you see a webcam for which the video resolution is listed in megapixels, expect the picture to be almost as tall as it is wide.
VGA is a descriptor that usually refers to x resolution, which is the same resolution of a standard definition television. Webcams that are VGA are not considered high-definition webcams. However, in the last 6 months, a number of manufacturers have begun touting their new megapixel cameras as HD.
Indeed, Axis emphasizes HD, rather than megapixel in its marketing, causing many to ask what is the difference and which is better? HD is a type of megapixel camera. All HD cameras are megapixel but not all megapixel cameras are HD. While standard definition cameras e. For most surveillance applications, the aspect ratio of HD cameras will be more efficient to the aspect of traditional megapixel cameras. In surveillance, you generally need to view far wider than you need to see high. The reason is that people and vehicles are only so tall but they can be anywhere across a wide area.
This is considered a 2 megapixel 2MP camera. Within this technology there is megapixel and HD. There are many similarities but also some differences between the two. For instance, all HD cameras are megapixel but not all megapixel cameras are HD. In HD technology p is the greatest pixel density but megapixel is available as high as 16MP. Another difference: HD has a aspect ratio, which is a wide screen type view, whereas megapixel typically has a aspect ratio.
This is squarer, like an older TV screen. Also, HD has quality compliance standards to meet whereas megapixel simply specifies the number of pixels. In the correct application HD and megapixel cameras can be of great advantage as well as cost effective. Because of the pixel density in this technology it is possible to look at large areas while maintaining the detail that would require multiple SD cameras.
This pixel density can allow the ability to zoom into the scene live or for forensic review, giving the system greater flexibility and performance.
How much you can zoom into the scene is determined by the area being viewed and the pixel density. To illustrate this, consider the application of wanting to view license plates within a scene. This typically requires 50 pixels per horizontal foot for a clear, readable image.
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