Tuesday, May 25, 2010

Beginning of May was a great time to windsurf at Aveiro.

In the beginning of this month I had some really great windsurf sessions. The one with the most violent winds was definitely on the 13 of May, winds averaging 35 knots but with strong gusts but also lot's of dead zones.

The most annoying thing with this kind of wind is that in on moment your a sitting duck, the board sinking in the water and a second later you're flying. The strain in your arms and shoulders rapidly wears you down. At the same time it's quite a challenge and I do love those.

Gybing becomes a question of looking into the water to see where the gust is and then using the gust to push you up to speed again.

All in all a great day. No at al like on the 3rd of May, where the wind blowing at 40 knots and my tiered hands of non stop afternoons of windsurfing were a conjugation that I could not overcome.

Of course the memory of what happened to me on the 27 of February didn't help.

On that day, with the weather forecast predicting a hurricane type wind me and other two valiant warriors decided to change our luck fighting the storm. All was going well until out of nowhere the gusts increased ten fold.

The Ria de Aveiro, usually a place of calm waters, become agitated. Small but with a very short period waves made it difficult to ride and as the wind gusts become stronger and stronger it was also impossible to keep the sail (4.1 m²). In the end a couple fishermen came with a rather heavy boat to pick me up. It was a really nice thing from them to do and I am truly grateful.

This storm did some damage in Portugal but as it moved North-West to France it even more troubles. I am happy to have fought and survived that day.

The two other wind warriors had two different stories to tell. One of then managed to get back by swimming with his gear. The other was dragged to the other side of the Ria, ending up with the board severely dented and quite a fright.

Tuesday, May 04, 2010

Setting the copyright exiv info on photos (or other kind of metadata)

I am one of those that still prefer the command line to GUI applications. For lot's of operations it's just faster. For example when setting the copyright information on photographs that I took I usually use the exiv2, a EXIF and IPTC metadata C++ library and command line utility.

To view the metadata associated with one photo:

# exiv2 -pa photo.jpg
and you can even look at the metadata of a series of photos using shell wildcards. Then the output will have a added column on the left with the filename of each photo.

For the single photo the output will be a series of lines with four columns:

  1. metadata name
  2. metadata type
  3. metadata size
  4. metadata value
Is you try it in a photo you'll see lot's of information like:
Exif.Image.Orientation                       Short       1  top, left
Exif.Image.XResolution                       Rational    1  72
Exif.Image.YResolution                       Rational    1  72
Exif.Image.ResolutionUnit                    Short       1  inch
Exif.Photo.ComponentsConfiguration           Undefined   4  YCbCr
Exif.Photo.CompressedBitsPerPixel            Rational    1  4
Exif.Photo.ShutterSpeedValue                 SRational   1  1/223 s
Exif.Photo.ApertureValue                     Rational    1  F9.8
Exif.Photo.BrightnessValue                   SRational   1  8.1
Exif.Photo.ExposureBiasValue                 SRational   1  0 EV
Exif.Photo.MaxApertureValue                  Rational    1  F3.5
Exif.Photo.MeteringMode                      Short       1  Average

Each of the metada entry can be set. For example to set the copyright the metadata name is "Exif.Image.Copyright" and to set it's value one can use the following command:

$ exiv2 -k -M"set Exif.Image.Copyright @My Name" *.jpg
which would set the copyright value for all the photos found on the current directory. Easy right?