[Gdal-dev] Getting started with raster processing with GDAL/OGR

[Lucena, Ivan]

André,

Since you are used to the GDAL Python API your transition from Vector to 
Raster shouldn't be hard at all.

 > The problem is that I don't have any experience creating raster data,
 > so although I'm pretty confident I could process the point data by
 > creating the b-box coords mathematically, I don't know how to create
 > an output raster and assign values to each pixel.

If what you have is a sell-space in a Python dictionary I believe that 
you can go thought the existing cells and pass the values to a raster 
buffer and then write it in a band (It could be optimized) line by line.

A very simplified sample code would be something like that:

###

import gdal
import Numeric

n_rows = 180 # your calculated
n_cols = 360 # values goes here

gdal.AllRegister()

tif_driver = gdal.GetDriverByName("gtiff")
tif_ds = tif_driver.Create("\Data\grid.tif", n_cols, n_rows, 1)
tif_rb = tif_ds.GetRasterBand(1)

buffer = Numeric.zeros((1, n_cols), Numeric.Int)
# attention:                                ^^^

# loop through all rows of your dictionary :

x = 11  #
x = 38   # hypothetical values in the middle of your loop
z = 4   #

    buffer[0][y] = z

    tif_rb.WriteArray(buffer, 0, x)

# end loop

tif_ds = None
tif_driver = None

###

You can also take a look at one of the GDAL command line utilities like 
pct2rgb.py for a more complete example.

Regards,

Ivan