ptp bypass SD card

Flessan

« on: 01 / December / 2014, 15:20:23 »

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I have mostly succeeded in loading chdk and ptp to use my Canon S5 IS as a web cam that will take images very 30 seconds or so for as long as it lasts

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I would like to have it save the image directly to the hard drive of the PC that the USB cable is connected to. I have ptpcam installed and working fine. I even installed the GUI version and can control the camera that way. I can basically do everything I need with the provided scripts EXCEPT bypass the SD card. From the ptp-extension page of the wiki:

Remote shootingEdit
CHDK 1.2 added support for saving images directly over USB, without saving on the SD card. This is supported for raw and DNG on all cameras, and for jpeg on some cameras. For raw and DNGs capturing a subset of rows from the raw framebuffer is also supported.

I want to bypass writing to the card to avoid so many write/erase cycles. I know that would wear out the card fairly quickly. I haven't found a way to do this yet. If anyone has the answer, I will be forever grateful! Thanks in advance!

Flessan

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srsa_4c

4451

Re: ptp bypass SD card

« Reply #1 on: 01 / December / 2014, 18:21:06 »

Upgrade to CHDK 1.3 and use the rs command of chdkptp (other client programs don't currently support this feature). chdkptp has a built-in help command, use that to learn more about its commands.
~~See also http://chdk.wikia.com/wiki/PTP_Extension for some more info and links.~~ you already know this page

edit:
Also, this camera has official remote capture support (CHDK is not needed for that), you can use gphoto and other utilities to utilise that.

« Last Edit: 01 / December / 2014, 18:39:16 by srsa_4c »

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Flessan

Re: ptp bypass SD card

« Reply #2 on: 01 / December / 2014, 21:26:07 »

Thanks for the info! I actually did get there eventually, but rs -jpg is not supported. I can only capture directly through USB to raw or dng (I think it was dng). I will explore gphoto as well. I noticed some bad (bright) pixels in the .dng when I loaded the image into photoshop elements 11.

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reyalp

13879

Re: ptp bypass SD card

« Reply #3 on: 01 / December / 2014, 23:32:06 »

Quote from: Flessan on 01 / December / 2014, 21:26:07

Thanks for the info! I actually did get there eventually, but rs -jpg is not supported.

It should be supported in current CHDK 1.3 trunk builds.

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I can only capture directly through USB to raw or dng (I think it was dng). I will explore gphoto as well. I noticed some bad (bright) pixels in the .dng when I loaded the image into photoshop elements 11.

using -badpix in the rs command will fix some bad pixels in the DNG. This only fixes 0 valued pixels, but they can cause bright saturated points because they only affect one of R, G, B elements. If your camera has "hot" pixels that also show up in jpeg, you will need to fix them separately.

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Flessan

Re: ptp bypass SD card

« Reply #4 on: 02 / December / 2014, 14:03:18 »

Version 1.3 is working great! Still have "hot" pixels that annoy me a little. These show up in both DNG and jpg mode. -badpix didn't take them away from the DNG. Oh well, I can live with it.

Thanks for your help reyalp and srsa_4c! Now for the fun part. Figuring out how to mount it under an eave of the house in a weatherproof box and run the electric and USB from there to the computer

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reyalp

13879

Re: ptp bypass SD card

« Reply #5 on: 02 / December / 2014, 21:17:20 »

Quote from: Flessan on 02 / December / 2014, 14:03:18

Version 1.3 is working great! Still have "hot" pixels that annoy me a little. These show up in both DNG and jpg mode. -badpix didn't take them away from the DNG. Oh well, I can live with it.

You can fix hotpixels with CHDK using the "manual badpixel removal" method: http://chdk.wikia.com/wiki/CHDK_User_Manual#Manual_bad_pixel_removal

You can create the badpixel file using chdkptp see https://www.assembla.com/spaces/chdkptp/wiki/DNG_Processing#generating_badpixel_lists

Note this just creates a list of pixels brighter than the value you specify, so the picture should be taken with the lens covered, in the dark, or with the shutter forced closed. It doesn't have to be totally dark, you just need the hot pixels to be significantly brighter than the real data. Your S5 has a 10 bit sensor, so the max value is 1023.

Quote

Thanks for your help reyalp and srsa_4c! Now for the fun part. Figuring out how to mount it under an eave of the house in a weatherproof box and run the electric and USB from there to the computer

You might find some useful threads in the hardware section, like http://chdk.setepontos.com/index.php?topic=10284.0

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Don't forget what the H stands for.