Hello Jose, MFSK pictures are analog SSTV not digital SSTV.
Here are the MFSK SSTV specifications (from the Multipsk help) 73 Patrick SSTV in MFSK16 Created by : Nick Fedoseev (UT2UZ) and Denis Nechitailov (UU9JDR) in 2003 Description : It is a SSTV mode without transmission of a synchronization ray, in color or in black and white mode, where the picture may be transmitted among MFSK16 text. The picture format is not fixed as in classical SSTV but variable (limited to small pictures). Multipsk proposes to use the standard "320x256" to take advantage of the SSTV "workshop" and the stored SSTV pictures. The band of frequencies used is 234,375 Hz (15 x 15,625 Hz), which is the width between extreme peaks of a MFSK16 transmission. The duration of a pixel is exactly 1 ms. In color mode, the colors are transmitted in the following order: Red, Green, Blue. In black and white mode, the black color corresponds to the lower frequency and the white color to the higher frequency. To be recognized, the picture must be MFSK16 prefixed by: * "Pic:320x256C;" for example for a color picture of 320x256 dimension whose transmission will last 320x256x3x0,001=246 sec, * "Pic:320x256C;" for example for a black and white picture of 320x256 dimension whose transmission will last 320x256x1x0,001=82 sec. Note: on this program, for a better appearance, the grey level is computed according to a "physiological" formula: Grey level = 0,30 x Red level + 0,59 x Green level + 0,11 x Blue level ----- Original Message ----- From: Jose A. Amador To: [email protected] Sent: Thursday, January 25, 2007 12:47 AM Subject: [digitalradio] Why MSFK images can be noisy? I have already received some small images sent by MFSK. But they are noisy, like analog SSTV. Why? How is it done? Where can I read about it? Jose, CO2JA
