Hi Andrey,
I think the JP4 image is lossy compressed. The block is cause by that. Is there
a way to get lossless images?
Thanks.
Tao Zhang
章 涛
发件人: Winston Zhang
发送时间: 2018年3月7日 13:12
收件人: Andrey Filippov <and...@elphel.com>
抄送: Elphel Support <support-list@support.elphel.com>; Elphel Sales | Olga
Filippova <sa...@elphel.com>; Tao Zhang <tao.zh...@blacksesame.com.cn>; Qun Gu
<qun...@blacksesame.com>; Pioneer Li <pioneer...@blacksesame.com.cn>
主题: 答复: [Elphel-support] 答复: 答复: 答复: sync stereo with lidar
Hi, Andrey
Please take a look at attachments. The rawJP4 image was captured from the
camera, and I converted it and got the result as result.png. But when I
magnified this image, I found some block included 16x16 grid. I did not know
the reason. Can you explain it.(The grid image please take look at grid.png).
Another question is that the result image is single channel but not three
channel like as rgb-channel. But if I converted it through the jp4viewer, the
result is color image. Why? How do you do this?
Best Regrad!
Yicheng-Zhang
Email:
winston.zh...@blacksesame.com.cn<mailto:winston.zh...@blacksesame.com.cn>
Teil: 18516291005
Addr: 707 room, 7th floor, building 4th, No.1761, Zhangdong road, Pudong area
发件人: Andrey Filippov [mailto:and...@elphel.com]
发送时间: 2018年3月6日 星期二 15:58
收件人: Winston Zhang
<winston.zh...@blacksesame.com.cn<mailto:winston.zh...@blacksesame.com.cn>>
抄送: Elphel Support
<support-list@support.elphel.com<mailto:support-list@support.elphel.com>>;
Elphel Sales | Olga Filippova <sa...@elphel.com<mailto:sa...@elphel.com>>; Tao
Zhang <tao.zh...@blacksesame.com.cn<mailto:tao.zh...@blacksesame.com.cn>>; Qun
Gu <qun...@blacksesame.com<mailto:qun...@blacksesame.com>>; Pioneer Li
<pioneer...@blacksesame.com.cn<mailto:pioneer...@blacksesame.com.cn>>
主题: Re: [Elphel-support] 答复: 答复: 答复: sync stereo with lidar
Winston,
There are several ways how to set the JP4 mode:
1) set it from the camera GUI (click Camera Control Interface port #), then
click camera icon (top left), then "More details" and select color mode to jp4.
2) set with "Parameter Editor": follow Parameter Editor from the home page,
check bit 2 - "Image color, quality ..." -> "View/Edit Current", set "COLOR:
line New value to 5 (it is jp4) and click "Apply" button.
3) make this mode default(after either 1) or 2) )- save current settings in
"Parameter Editor" (previous page) - Press topmost "Save" button (you may later
change comments for the settings). Then you may set saved settings as default
(select it and then press "Update default"). Next time you start the camera it
will use these settings.
Then repeat the same for the other channel.
Andrey
---- On Mon, 05 Mar 2018 01:46:22 -0800 Winston
Zhang<winston.zh...@blacksesame.com.cn<mailto:winston.zh...@blacksesame.com.cn>>
wrote ----
Hello, Andrey,
I need information inside camera. How can I get jp4 format image?
What is the image default format? If I try the command line “wget
http://192.168.0.9:2323/img -O
filename.jp4<http://192.168.0.9:2323/img%20-O%20filename.jp4>”, Can I get the
jp4 format Image?
Thank you!
”
Best Regrad!
Yicheng-Zhang
Email:
winston.zh...@blacksesame.com.cn<mailto:winston.zh...@blacksesame.com.cn>
Teil: 18516291005
Addr: 707 room, 7th floor, building 4th, No.1761, Zhangdong road, Pudong area
发件人: Andrey Filippov [mailto:and...@elphel.com<mailto:and...@elphel.com>]
发送时间: 2018年3月2日 星期五 10:47
收件人: Winston Zhang
<winston.zh...@blacksesame.com.cn<mailto:winston.zh...@blacksesame.com.cn>>;
Elphel Support
<support-list@support.elphel.com<mailto:support-list@support.elphel.com>>
抄送: Tao Zhang
<tao.zh...@blacksesame.com.cn<mailto:tao.zh...@blacksesame.com.cn>>; Elphel
Support
<support-list@support.elphel.com<mailto:support-list@support.elphel.com>>;
Elphel Sales | Olga Filippova <sa...@elphel.com<mailto:sa...@elphel.com>>; Qun
Gu <qun...@blacksesame.com<mailto:qun...@blacksesame.com>>; Pioneer Li
<pioneer...@blacksesame.com.cn<mailto:pioneer...@blacksesame.com.cn>>
主题: Re: 答复: 答复: [Elphel-support] sync stereo with lidar
Hello Winston,
Do you need information inside camera or for post-processing on a host PC?
Sensor has 12 bits, and using JP4 format (https://wiki.elphel.com/wiki/JP4) you
can restore image data with the error less than the pixel shot noise
Here is an article explaining why it is so:
http://linuxdevices.io/how-many-bits-are-really-needed-in-the-image-pixels/
With ImageJ plugin you can convert JP4 file to 32-bit TIFF
Andrey
---- On Thu, 01 Mar 2018 17:17:14 -0800 Winston
Zhang<winston.zh...@blacksesame.com.cn<mailto:winston.zh...@blacksesame.com.cn>>
wrote ----
Hello,
Does this camera image pixel have 10 bit of the single channel? And how
can I get it? Thank you.
Best Regrad!
Yicheng-Zhang
Email:
winston.zh...@blacksesame.com.cn<mailto:winston.zh...@blacksesame.com.cn>
Teil: 18516291005
Addr: 707 room, 7th floor, building 4th, No.1761, Zhangdong road, Pudong area
发件人: Andrey Filippov [mailto:and...@elphel.com<mailto:and...@elphel.com>]
发送时间: 2018年2月1日 星期四 13:49
收件人: Tao Zhang
<tao.zh...@blacksesame.com.cn<mailto:tao.zh...@blacksesame.com.cn>>
抄送: Elphel Support
<support-list@support.elphel.com<mailto:support-list@support.elphel.com>>;
Elphel Sales | Olga Filippova <sa...@elphel.com<mailto:sa...@elphel.com>>;
Winston Zhang
<winston.zh...@blacksesame.com.cn<mailto:winston.zh...@blacksesame.com.cn>>;
Qun Gu <qun...@blacksesame.com<mailto:qun...@blacksesame.com>>; Pioneer Li
<pioneer...@blacksesame.com.cn<mailto:pioneer...@blacksesame.com.cn>>
主题: Re: 答复: [Elphel-support] sync stereo with lidar
Tao,
USB GPS does not have 1pps signal (only serial has), precise synchronization is
not possible that way. GPS time is available in each frame Exif header data -
recorded on internal SSD or sent over the network.
The high resolution time stamps (1 microsecond step) are also provided with
each image, but they use internal camera clock, not the GPS.
This is why for precise synchronization you need to use event logger- it
records events and timestamps them using the same clock.
If you had serial GPS with https://wiki.elphel.com/wiki/103696 - you would
still need to use event logger - with serial GPS there will be 1 PPS precise
GPS events timestamped with camera internal clock, and the images timestamped
wit the same clock - that provides absolute calibration for the camera internal
clock.
Without serial GPS you may use pulses from the LIDAR (it is possible to provide
LIDAR pulse number over the Ethernet in addition to the precise time over the
sync cable)
Andrey
---- On Wed, 31 Jan 2018 18:12:00 -0800 Tao
Zhang<tao.zh...@blacksesame.com.cn<mailto:tao.zh...@blacksesame.com.cn>> wrote
----
Hi Andrey,
We prefer to use GPS to synchronize stereo with lidar.
Where do those images that contain timestamp store in internal disk? Can we get
it from ethernet continuously?
Tao Zhang
章 涛
发件人: Andrey Filippov [mailto:and...@elphel.com<mailto:and...@elphel.com>]
发送时间: 2018年2月1日 1:52
收件人: Tao Zhang
<tao.zh...@blacksesame.com.cn<mailto:tao.zh...@blacksesame.com.cn>>
抄送: Elphel Support
<support-list@support.elphel.com<mailto:support-list@support.elphel.com>>;
Elphel Sales | Olga Filippova <sa...@elphel.com<mailto:sa...@elphel.com>>;
Winston Zhang
<winston.zh...@blacksesame.com.cn<mailto:winston.zh...@blacksesame.com.cn>>;
Qun Gu <qun...@blacksesame.com<mailto:qun...@blacksesame.com>>; Pioneer Li
<pioneer...@blacksesame.com.cn<mailto:pioneer...@blacksesame.com.cn>>
主题: Re: [Elphel-support] sync stereo with lidar
Hi Tao,
There are several ways how to do that:
One method would be be to get camera sync pulses for each frame and use
external electronics to match with the LIDAR.
Another is to provide pulses from the LIDAR to the camera and record them with
in-camera FPGA logger (https://wiki.elphel.com/wiki/Event_logger), together
with the camera frames. In this case the camera will record 2 types of events:
- image frames with the frame number, frame timestamp that will be recorded
in each frame header as Exif.
- external pulse
Each of the two types of events will have a logger timestamp (with microsecond
resolution). Logger can also record GPS timestamps (for serial GPS only and
103696 board -https://wiki.elphel.com/wiki/103696) and IMU
(https://wiki.elphel.com/wiki/103695), in your case there are just 2 types
listed above.
Both output (+5V pulses) and input (3.3V..5.0V) are available through the 2.5mm
audio connector (marked "sync"
https://wiki.elphel.com/images/0/0f/NC393-CS_marked_ports.jpeg ), here is the
pinout and description: https://wiki.elphel.com/wiki/103891 .
Andrey
---- On Wed, 31 Jan 2018 04:19:04 -0800 Tao
Zhang<tao.zh...@blacksesame.com.cn<mailto:tao.zh...@blacksesame.com.cn>> wrote
----
Hi Andrey,
We are going to use stereo with lidar. We need to sync stereo frames with lidar
point cloud. Do you have any suggestions on how to do that?
Thanks.
Tao Zhang
章 涛
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