Hello Theodore
kilgota@xxxxxxxxxxxxxxxxxxxxxx wrote:
On Wed, 4 Mar 2009, Thomas Kaiser wrote:
As to the actual contents of the header, as you describe things,
0. Do you have any idea how to account for the discrepancy between
From usb snoop.
FF FF 00 FF 96 64 xx 00 xx xx xx xx xx xx 00 00
and
In Linux the header looks like this:
FF FF 00 FF 96 64 xx 00 xx xx xx xx xx xx F0 00
(I am referring to the 00 00 as opposed to F0 00)? Or could this have
happened somehow just because these were not two identical sessions?
Doesn't remember what the differences was. The first is from Windoz
(usbsnoop) and the second is from Linux.
1. xx: don't know but value is changing between 0x00 to 0x07
as I said, this signifies the image format, qua compression algorithm in
use, or if 00 then no compression.
On the PAC207, the compression can be controlled with a register called
"Compression Balance size". So, I guess, depending on the value set in
the register this value in the header will show what compression level
is set.
2. xx: this is the actual pixel clock
So there is a control setting for this?
Yes, in the PAC207, register 2. (12 MHz divided by the value set).
3. xx: this is changing according light conditions from 0x03 (dark) to
0xfc (bright) (center)
4. xx: this is changing according light conditions from 0x03 (dark) to
0xfc (bright) (edge)
5. xx: set value "Digital Gain of Red"
6. xx: set value "Digital Gain of Green"
7. xx: set value "Digital Gain of Blue"
Does anyone have any idea of how actually to use this information/ for
example, since a lot of cameras are reporting some kind of similar
looking information, does anyone know if there are any kinds of standard
scales for these entries? Just what are they supposed to signify, and
how exactly is one supposed to use such values, if they have been
presented? When I say "a lot of cameras," understand, I mean still
cameras as well as webcams, and cameras with a lot of different chipsets
in them, too. So this is a question whether there is any standard system
for the presentation of such data, and how it might constructively be
used in image processing. I have had questions about this kind of thing
for a long time, and I do not know where to look for the answers.
For the brightness, I guess, 0 means dark and 0xff completely bright
(sensor is in saturation)?
Thomas
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