Datasheet
RECORDING SOLUTIONS 31TECHNICAL CORNER / Megapixel, HDTV34
MEGAPIXEL
The higher the resolution, the more details can be seen
in an image. This facilitates the identication of ob-
jects and persons – important considerations in video
surveillance. Megapixel resolution allows the same
scene to be viewed in greater detail, or a larger scene
to be viewed at a maintained resolution. The higher
resolution also means that digital pan/tilt/zoom can be
used without causing a drop in resolution.
After the video signal from an NTSC or PAL analog
camera has been digitized, the maximum resolution
will be 0.4 megapixel. New network camera technology
makes higher resolutions possible.
One common megapixel format is 1280x1024, which
gives 1.3-megapixel resolution, 3 times higher than
analog cameras. Cameras that provide multi-megapix-
el resolutions are also available. It is, however, impor-
tant to bear in mind that higher resolutions generally
lead to reduced light sensitivity because of the smaller
pixels in the image sensor as compared with conven-
tional cameras.
The full 1600x1200 resolution provided by, for example, AXIS P1346
Network Camera gives more than 4 times the number of pixels com-
pared with a high-resolution analog camera.
HIGH-DEFINITION TELEVISION (HDTV)
Axis HDTV network cameras comply with SMPTE
(Society of Motion Picture and Television Engineers)
standards with regard to HDTV resolutions and frame
rates, HDTV color delity and a 16:9 format. The two
most important HDTV standards are SMPTE 296M and
SMPTE 274M.
SMPTE 296M (HDTV 720p) denes a resolution of
1280x720 pixels with high color delity in a 16:9 for-
mat using progressive scanning at 25/30 Hertz (Hz),
which corresponds to 25 or 30 frames per second de-
pending on the country, or at 50/60 Hz (50/60 frames
per second).
SMPTE 274M (HDTV 1080) denes a resolution of
1920x1080 pixels with high color delity in a 16:9
format using either interlaced or progressive scanning
at 25/30 Hz or 50/60 Hz.
HDTV/Megapixel network camera resolution, 16:9 ratio
Analog camera resolution,
4:3 ratio