AXIOM Alpha Software

1 Register Memory Space

Image sensor related registers: 0x60xxxxxx

cmv.func contains the functions to deal with this address space

HDMI related registers: 0x80xxxxxx

hdmi.func contains the functions to deal with this address space

0xU0VWWWWW
U = image sensor or HDMI
V = register block
WWWWW =  addresses inside a register block

Register Addresses HDMI:

0x800xxxxx = scan generator
0x801xxxxx = address generator
0x802xxxxx = component matrix 4x4
0x803xxxxx = 4 channel 12bit LUT
0x804xxxxx = HDMI PLL dynamic reconfig

Register Addresses Image Sensor:

0x600xxxxx = CMV SPI registers
0x601xxxxx = address generator/capture control
0x602xxxxx = LVDS input delay registers
0x603xxxxx = column/row noise LUTs

Examples:

0x60000000 = sensor, register block 0, address 0 (CMV register 0)

2 Reading and Writing Sensor Register

Execute the script that contains the sensor interface functions before we can use them:

. ./cmv.func

Set Sensor register 82 to the decimal value "3122"

cmv_reg  82   3122

Read Register 82:

 cmv_reg  82

will output:

0x00000C31

2.1 statically linked busybox

http://vserver.13thfloor.at/Stuff/AXIOM/FAKE/

builtin fake devmem

all you need to get it to work is the following:

dd if=/dev/zero of=/tmp/mem bs=1k seek=4M count=1

this will create a sparse 4GB file /tmp/mem, which will be used by the fake devmem values written can be read back, non existing values return 0

/bin/sh and /sbin/devmem both link to busybox on the axiom alpha filesystem so both can be tested with this executeable

3 Capturing an Image

Preparations:

ssh root@*alpha-IP* "./cmv_train2

Capture the image:

ssh root@*alpha-IP* "./cmv_snap2 -e 10ms" | tee snap.raw16 | display -size 4096x3072 -depth 16 gray:-

So we dont need to type the password every time we snap an image:

Install:

sudo apt-get install sshpass

Use:

sshpass -p '1234' ssh root@*alpha-IP* "./cmv_snap2 -e 10ms" | tee snap.raw16 | display -size 4096x3072 -depth 16 gray:-

4 cmv_snap2

./cmv_snap2 -h
This is ./cmv_snap2 V1.5
options are:
-h        print this help message
-8        output 8 bit per pixel
-b        enable black columns
-r        dump sensor registers
-t        enable cmv test pattern
-e <exp>  exposure time
-m <val>  capture mask and value
-n <num>  number of frames
-s <num>  shift values by <num>
-B <val>  register mapping base
-S <val>  register mapping size
-M <val>  buffer memory base
-Z <val>  buffer memory size
-R <fil>  load sensor registers
-P <pat>  idle pattern

"./cmv_snap2 -r" without an -e parameter outputs only registers

5 cmv_hist2

Outputs RAW histogram data of the last captured image. Values are tab separated in 4 columns (Order: GRBG[image flip on], RGGB[image flip off]) with 4096 values (when operating in 12 bit mode) each.

Download: http://vserver.13thfloor.at/Stuff/AXIOM/cmv_io2/cmv_hist2

./cmv_hist2
This is ./cmv_hist2 V1.0
options are:
-h        print this help message
-s        acquire snapshot
-B <val>  register mapping base
-S <val>  register mapping size
-M <val>  buffer memory base
-Z <val>  buffer memory size

Real Time Histogram Plot

5.1 Examples

./cmv_hist2 -s

Acquire new snapshot and output histogram

./cmv_hist2

Acquire histogram from last captured snapshot in memory

6 cmv_train2

Executes the LVDS training routines to align LVDS reading timing. Execute this script when the Axiom Alpha prototype is booted up before you capture any images:

./cmv_train2

./cmv_train2 -h
This is ./cmv_train2 V1.0
options are:
-h        print this help message
-a        test all bit pattern
-B <val>  memory mapping base
-S <val>  memory mapping size
-A <val>  memory mapping address
-P <val>  training pattern

7 Post Processing images

7.1 Create RGGB separated color images from raw file:

convert -size 4096x3072 -depth 16 -crop +0+0 -sample 2048x1536 gray:colors_500ms.raw16 gray:colors_500ms_ch0.raw
convert -size 4096x3072 -depth 16 -crop -1+0 -sample 2048x1536 gray:colors_500ms.raw16 gray:colors_500ms_ch1.raw
convert -size 4096x3072 -depth 16 -crop +0-1 -sample 2048x1536 gray:colors_500ms.raw16 gray:colors_500ms_ch2.raw
convert -size 4096x3072 -depth 16 -crop -1-1 -sample 2048x1536 gray:colors_500ms.raw16 gray:colors_500ms_ch3.raw

7.2 Simple debayer with ImageMagick:

For flipped images:

convert \( -size 4096x3072 -depth 16 gray:colors_500ms.raw16 \) \
\( -clone 0 -crop -1-1 \) \( -clone 0 -crop -1+0 \) \( -clone 0 -crop +0-1 \) \
-sample 2048x1536 \( -clone 2,3 -average \) -delete 2,3 -swap 0,1 +swap -combine colors_500ms.png

For unflipped images:

convert \( -size 4096x3072 -depth 16 gray:IT8_incand.raw16 \) \
\( -clone 0 -crop -1-1 \) \( -clone 0 -crop -1+0 \) \( -clone 0 -crop +0-1 \) \
-sample 2048x1536 \( -clone 0,1 -average \) -delete 0,1 +swap -combine IT8_incand.png

7.3 Plot Histogram of Raw Image

Create histogram values file with imagemagick:

convert -size 4096x3072 -depth 16 gray:image.raw16 -format "%c" histogram:info: > histogram.hist

Reformat the file:

gawk -F, '(NF>3) { printf "%d\t%d\n", $2/16, $1 }' 

Or all in one command:

convert -size 4096x3072 -depth 16 gray:image.raw16 -format %c histogram:info:- | gawk -F, '(NF>3) { printf "%d\t%d\n", $2/16, $1 }' > histogram.info

Then draw it with this gnuplot script:

set notitle
set term svg size 1024, 512
set xlabel "Values"
set ylabel "Number of Pixels"
set multiplot
set obj 1 rectangle behind from screen 0,0 to screen 1,1
set obj 1 fillstyle solid 1.0 fillcolor rgbcolor "white"
set xrange[0:4096]
set yrange[0:8000]
plot 	'histogram.info' using 1:2	with lines lc rgb "#FF0000"	title "name your curve", \
       'histogram2.info' using 1:2	with lines lc rgb "#FF0000"	title "name your curve"
unset multiplot

execute the script with:

gnuplot thescript > output.svg

8 chroot environment on Axiom Alpha

Full raspian image is available on the alpha prototype in a changeroot environment to keep the core system free from too much clutter.

Download:

http://vserver.13thfloor.at/Stuff/AXIOM/raspian.tar.xz

Preferably download from the alpha prototype directly and upack into /opt/raspian, moving files to the prototype using Filezilla has produced some problems.

Map required folders:

mount -o bind /proc /opt/raspian/proc
mount -o bind /tmp /opt/raspian/tmp

Changeroot:

chroot /opt/raspian/ /bin/bash

9 Live HDMI video output

Init:

./cmv_train3 -a
./setup.sh

Run Video Acquisition:

time ./cmv_snap3 -N 0 -z -e 25ms

Alternative (slower):

while true; do ./cmv_snap3 -z -e 32ms 2>/dev/null; done

10 Update Firmware

u-boot access:

mount /dev/mmcblk0p1 /mnt/

11 Real Time FPN correction

FPN correction supports a 9bit signed value for each column and row.

9 bit signed integer means:

0xFF = 255 (highest possible positive value)
0x1FF = -1
0x100 = -256 (lowest possible negative value

To obtain the correct value (for -7 in this case) to set you can run:

echo $(( -7 & 0x1FF ))

which outputs (in decimal)

505

To set a value use syntax:

devmem address 32 value

or with actual values:

devmem 0x60304000 32 0xFF

Adresses are:

0x60300000 = even columns, 2048 total
0x60304000 = odd columns, 2048 total
0x60308000 = even rows, 2048 total (only first 1576 are used)
0x6030C000 = odd rows, 2048 total (only first 1576 are used)

each row/column address increases by 4 from current to next row/column.

Row/Column 0 is in the top left corner.

11.1 Balance (FPN profiling tool)

Download: http://vserver.13thfloor.at/Stuff/AXIOM/balance

balance can extract a DSNU profile from a darkframes and apply the created profile to correct an image.

Usage:

Extract FPN profile:

./balance -b -o darkframe.raw16 > profile.offsets

Apply FPN profile to image:

./balance -b -O profile.offsets image.raw16 > image_balanced.raw16

Only use the -b parameter if the image uses darkcolumns.

The profile.offsets file format is:

row-numer offset (double) then column number (double)

(3072+4096)x8 = 57344 Bytes = 57KB

One double is 8 bytes (64 bits)

12 Matrix Color Conversation

Each color channel is going through 4 stages that each look like this: (I+A)*E+O

I = input (25bit unsigned)
A = adjustment (30bit signed)
E = matrix coefficient (18bit signed)
O = offset (48bit signed)

The four stages are connected together that the offset of stage N is the output of stage N-1. The offset of stage 1 is set in registers (32-35). The output of stage 4 is the final result.

For each channel that results in the following fomular:

Ri = SUMj ((Ij + Aij) * Eij) + Oi

Which in other words mean the result of matrix (Eij) multiplied with an input vector (Ij + Aij) plus an offset vector (Oi).

Currently all registers (beside input/output) are shortened to 16bit signed (this could be changed easily) values so the matrix is currently limited to 1/256 of the possible accuracy (due to a 8bit shift of the output).

All input /output register are tested for over/underflow and clipped to 12 bit (this can also be disabled).

Setting/Getting Registers:

. ./hdmi.func # load functions

mat_reg 0 # Read value of register 0 = A0
mat_reg 0 1 # Sett value of register 0 (A0) to 1

4x4 matrix coefficients (A0, A1, A2, A3, B0, B1, B2, B3, B4, C0, C1, C2, C3, D0, D1, D2, D3) are mapped to addresses 0 - 15. In registers 16 - 31 there are adjustment values and from 32 - 35 there are 4 offset values.

Input format per default is (R, G1, G2, B).

All values of the 4x4 matrix can be set conveniently with this script:

Syntax:

./mat4_conf.sh  A0 A1 A2 A3  B0 B1 B2 B3 B4  C0 C1 C2 C3  D0 D1 D2 D3    O1 O2 O3 O4

Examples:

./mat4_conf.sh  1 0 0 0  0 1 0 0  0 0 1 0  0 0 0 1    0 0 0 0   # unity matrix but not optimal as both green channels are processed separately
./mat4_conf.sh  1 0 0 0  0 0.5 0.5 0  0 0.5 0.5 0  0 0 0 1    0 0 0 0   # the two green channels inside each 2x2 pixel block are averaged and output on both green pixels
./mat4_conf.sh  0 0 0 1  0 1 0 0  0 0 1 0  1 0 0 0    0 0 0 0   # red and blue are swapped
./mat4_conf.sh  1 0 0 0  0 1 0 0  0 0 1 0  0 0 0 1    0.5 0 0 0    # red 50% brigther
./mat4_conf.sh  1 0 0 0  0 1 0 0  0 0 1 0  0 0 0 1.5    0 0 0 0    # blue multiplied with factor 1.5
./mat4_conf.sh  .25 .25 .25 .25  .25 .25 .25 .25  .25 .25 .25 .25  .25 .25 .25 .25    0 0 0 0    # black/white
./mat4_conf.sh  -1 0 0 0  0 -0.5 -0.5 0  0 -0.5 -0.5 0  0 0 0 -1    1 1 1 1    # negative

An RGB 3x3 matrix can easily be extended to a 4x4 matrix by using the coefficient for green and offsets twice or better to half both of the green coefficients and use the same value for both greens.