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by perrociego
Fri Mar 22, 2019 1:01 am
Forum: Camera board
Topic: utilizing frex and strobe pads for ov5647 (probable solution for rolling shutter issue?)
Replies: 19
Views: 2615

Re: utilizing frex and strobe pads for ov5647 (probable solution for rolling shutter issue?)

A bit of sand: Most active sensor CMOS use 3 transistor per pixel. For an electronic GLOBAL SHUTTER 4 to 5 transistor per pixel are required. If a remember right the problem, the difficult part, is not all the pixels beginning the exposure at the same time (the reset) but ending the exposure and avo...
by perrociego
Tue May 15, 2018 11:47 pm
Forum: Camera board
Topic: Distance Between Stock Lens and Camera Sensor
Replies: 2
Views: 423

Re: Distance Between Stock Lens and Camera Sensor

Focal length is 3 mm*.
So the real distance (from the center of the lens to the sensor) should be between 3 and 3.3 mm.

Marcelo

*from jbeale at viewtopic.php?t=150344#p988445
by perrociego
Sun May 06, 2018 4:58 pm
Forum: Camera board
Topic: multi exposure filming
Replies: 8
Views: 1398

Re: multi exposure filming

Hi Tom:

Perhaps you may take photos at that speed (10 fps) changing parameters before each.
You will have to make the video / videos from the photos after that.

Marcelo
by perrociego
Tue Feb 20, 2018 1:27 am
Forum: Camera board
Topic: v2 camera module wide angle lens
Replies: 5
Views: 1913

Re: v2 camera module wide angle lens

Hi phrasp:

Your formulae is wrong. From Wikipedia: FOV = 2 arctan(SensorSize/2f), where f is focal length.

Also, try not using others posts for yours questions.
by perrociego
Sun Sep 17, 2017 5:56 pm
Forum: Camera board
Topic: Light bulb power line flicker observed with 125fps video
Replies: 1
Views: 805

Re: Light bulb power line flicker observed with 125fps video

Hi Hermann: You could record flicker at almost any fps. Tungsten light bulbs flicker at 100 pulses by second (on 50 Hz AC) (or 120 at 60 Hz). Specially the small ones (25 W - 40W). Most evident is in fluorescent lamps with magnetic ballast (the heavy ones, instead of the electronics). There are othe...
by perrociego
Sat Aug 19, 2017 12:51 am
Forum: Camera board
Topic: faster raw (bayer) procesing
Replies: 8
Views: 1557

Re: faster raw (bayer) procesing

Hi guys:

I was looking for a very fast raw to ppm conversion once and I get 0.46 s / photo with a very very optimized C code. (8 bits, half resolution)

viewtopic.php?f=43&t=146310&p=1117389#p1117389

Marcelo
by perrociego
Wed May 17, 2017 2:26 am
Forum: Camera board
Topic: camera_slave.c
Replies: 3
Views: 1302

Re: camera_slave.c

Great project. And advancing very fast. Thanks for sharing. Marcelo
by perrociego
Fri Apr 14, 2017 6:21 am
Forum: Camera board
Topic: Pi Camera V2 raw bayer data
Replies: 56
Views: 23294

Re: Pi Camera V2 raw bayer data

Hi schoolpost:

Do you know how long does it take to your code to process an image?

Thanks for sharing

Marcelo
by perrociego
Fri Apr 14, 2017 6:10 am
Forum: Camera board
Topic: Pi Camera V2 raw bayer data
Replies: 56
Views: 23294

Re: Pi Camera V2 raw bayer data

Hi Brian:

I tried the second code. It`s outputs is a .ppm without header. You may open it with Photoshop. 8 bits per color.

And I just tryng to understand the first one. Look quite good. It´s clear 16 bits.

8 bit´s vs 16 bit´s. Images wont look the same.
by perrociego
Thu Apr 13, 2017 3:16 pm
Forum: Camera board
Topic: Pi Camera V2 raw bayer data
Replies: 56
Views: 23294

Re: Pi Camera V2 raw bayer data

There are a few steps to get a .ppm image file from a RP_imx219 raw image. You got some examples in this post. Or better Dave Jones: http://picamera.readthedocs.io/en/release-1.13/recipes2.html?highlight=raw#raw-bayer-data-captures Before begining you may verify the existance of the magic word BRCM ...
by perrociego
Wed Apr 12, 2017 2:39 pm
Forum: Camera board
Topic: Pi Camera V2 raw bayer data
Replies: 56
Views: 23294

Re: Pi Camera V2 raw bayer data

On the IMX219 the Bayer pattern is:

GR
BG

I didnt try on flipped images.

Marcelo
by perrociego
Tue Feb 21, 2017 6:32 am
Forum: Camera board
Topic: Pi Camera V2 raw bayer data
Replies: 56
Views: 23294

Re: Pi Camera V2 raw bayer data

Hi everyone. I was using dcraw to decode raw images for my super8 transfer project, but it was too slow (10 s) so I decided to try a reduced but faster version of Dave Jones code. ( https://picamera.readthedocs.io/en/release-1.12/recipes2.html#raw-bayer-data-captures Jpg was not an option for me bec...
by perrociego
Sun Jan 29, 2017 3:33 pm
Forum: Camera board
Topic: Pi Camera V2 raw bayer data
Replies: 56
Views: 23294

Re: Pi Camera V2 raw bayer data

Exactly. Raw usually means before demosaicing. The code above generate an already demosaiced image.
The good for me is that it bypass the internal processing (lens shading correction), the bad is that I still cant adjust it properly. :roll:
by perrociego
Sat Jan 28, 2017 11:37 pm
Forum: Camera board
Topic: Pi Camera V2 raw bayer data
Replies: 56
Views: 23294

Re: Pi Camera V2 raw bayer data

Hi to everyone I´m quite new with all these but my little grain of sand on decoding raw photos from the Raspberry Pi camera V2.1 I get raw photos using Dave Jones' code: import time import picamera import picamera.array import numpy as np with picamera.PiCamera() as camera: with picamera.array.PiBay...

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