A few Problems

In recent days, there have been a few problems:

The automatic gain control of the camera seems not to operate properly. In the morning, after sunset when the image gets very bright, the gain control does not properly adjust and instead remains on a very high sensitivity setting, therefore completely overexposing the picture. The reason for this is not clear; it may be that the PC is not powerful enough, because the gain control appears to be done through the software device driver. I had to restart the camera capture, then the gain control worked again.

Today the weather here in Leeds was so warm and sunny, that the room in which the camera is hosted, heated up significantly. This prompted some people in the room to open the window - and this knocked down the camera, so for a while the image was taken while the camera was simply dangling from its cable. I did now place the camera at a higher location, so that opening the window would not disturb its mounting.

Right now the cam is operating properly, but it needs a close watch, in terms of the faulty gain control and the mounting position.

Small Problems - Solved

This morning there had been a strange problem: the images were captured, but were all white. This had to do with the automatic camera exposure control, which failed to work. so the image was on "night" setting, with open aperture and full exposure, then hereby overexposing when the sun came out. It should automatically correct, because the auto-exposure setting is on. But I noticed this behavior already earlier some time ago: the exposure control does not always work, when the framerate of the camera itself is set to a low value (10 pic per second). I had to restart the camera, then the problem solved itself.

The other issue had a different cause: It appeared that when loading this blog web page, then in the beginning, there is no image shown. Only after the first refresh the image appeared. The reason for this error had not been apparent; in separate test of the script, the image appeared always the very first time; only in the blog there seemed this issue. The principle of the image display had been that in order to save bandwidth, a temporary image was created on the server, based on the requests for image size. This ensured that when only a small image is requested, for example from a mobile phone, then only the image in the resized form would be transmitted. This works fine - except in the blog when loaded for the first time. It appears that the image file creation takes too long, and the file is not ready when it is supposed to be shown. Still, not yet explainable, as an earlier PHP query for the file shows its size, indicating that it already exists. But for some reason, the <img> tag then is still not able to produce the image. The solution: I abandoned for now the image resizing, and the script is now sending the full image out, independent for the size request. This at least works, and the image is available without delay.

Camera again showing the Acre

Finally, the web cam again shows the James Graham Building and the North end of The Acre at the Headingley Campus of Leeds Metropolitan University. After much popular demand for this view, I did set it up again this afternoon. This time, the view is even better than the previous Acre view, showing the scenery from the 2nd floor of Caedmon. This is definitely a more glorious view than the one onto the back parking lot from my window. I hope the webcam and the software will run reliably for a long time!

After more than 6 months of inactivity, the Headingley Caedmon webcam is active again. The camera had broken at the end of February, and since the setup (camera and computer) was in a different office than mine, I did not replace it. Now because of a restructuring of office locations, that office where the camera was located is now vacant again, and I got the system and set it up in my own office. The view from there is not as grand as the one onto the Acre, instead it goes onto the back of the Caedmon building, onto the parking lot between Caedmon Hall and Priestley Hall. In the back is the building of the Student Union visible. Well, better than nothing! At least I do have the camera and its setup again under my immediate control, and hopefully I will be able to maintain it properly.