How to georeference photo files / Cómo georeferenciar archivos fotográficos

1º Instalamos lo necesario:

root@ordenata:~$ apt-get install geotiff-bin

El comando más habitual es:

geotipcp -e archivo.tfw origen.tif destino.tif

Las instrucciones son:

usage: gtiffcp [options] input... output

where options are:

-g file install GeoTIFF metadata from <file>

-4 proj4_str install GeoTIFF metadata from proj4 string

-e file install positioning info from ESRI Worldfile <file>

-a append to output instead of overwriting

-o offset set initial directory offset

-p contig pack samples contiguously (e.g. RGBRGB...)

-p separate store samples separately (e.g. RRR...GGG...BBB...)

-s write output in strips

-t write output in tiles

-i ignore read errors

-d truncate 8 bitspersample to 4bitspersample

-r # make each strip have no more than # rows

-w # set output tile width (pixels)

-l # set output tile length (pixels)

-f lsb2msb force lsb-to-msb FillOrder for output

-f msb2lsb force msb-to-lsb FillOrder for output

-c lzw[:opts] compress output with Lempel-Ziv & Welch encoding

-c zip[:opts] compress output with deflate encoding

-c jpeg[:opts]compress output with JPEG encoding

-c packbits compress output with packbits encoding

-c g3[:opts] compress output with CCITT Group 3 encoding

-c g4 compress output with CCITT Group 4 encoding

-c none use no compression algorithm on output

Group 3 options:

1d use default CCITT Group 3 1D-encoding

2d use optional CCITT Group 3 2D-encoding

fill byte-align EOL codes

For example, -c g3:2d:fill to get G3-2D-encoded data with byte-aligned EOLs

JPEG options:

# set compression quality level (0-100, default 75)

r output color image as RGB rather than YCbCr

For example, -c jpeg:r:50 to get JPEG-encoded RGB data with 50% comp. quality

LZW and deflate options:

# set predictor value

For example, -c lzw:2 to get LZW-encoded data with horizontal differencing

Y un ejemplo de archivo.tfw sería:

0.0096628

0.00257495

0.00257495

-0.0096628

618251.334935

4849230.18706

es decir:

|Vx1, Vx2| es el tamaño del pixel en la dirección x

|Vy1, Vy2| es el tamaño del pixel en la dirección y

Px, Py son las coordenadas del punto de origen.