From: Petter Reinholdtsen Date: Sun, 1 May 2005 14:24:02 +0000 (+0000) Subject: More formatting. X-Git-Url: http://pere.pagekite.me/gitweb/homepage.git/commitdiff_plain/ab67318740dea20996be43e1974b61e637e79f5c?hp=223bf79cf86e7d185c26d128366bc4e92469728f More formatting. --- diff --git a/mypapers/drafts/geg2210/assignment-8.html b/mypapers/drafts/geg2210/assignment-8.html index 098d7ea601..79531c0b7d 100644 --- a/mypapers/drafts/geg2210/assignment-8.html +++ b/mypapers/drafts/geg2210/assignment-8.html @@ -92,69 +92,81 @@ separation between features. Displaying colour images ------------------------ -Comparing a map we found on the web, - +

Comparing a map we found on the web, + and the standard infrared image composition, we can identify some features from the colors used: - - water is black or green +

+ +

Next, we tried to shift the frequencies displayed to use blue for the red band, green for the near ir band and red for the mid ir (1.55-1.75 um). With this composition, we get some changes in the colours of different features: - - water is black +

Filtering and image sharpening

-We decided to work on the grey scale version of the thermal infrared. +

We decided to work on the grey scale version of the thermal infrared. This one has lower resolution then the rest of the bands, with 120m spatial resolution while the others have 30m spatial resolution. -The high pass filtering seem to enhance the borders between the +

The high pass filtering seem to enhance the borders between the pixels. Edge detection gave us the positions of glaciers and water. We tried a gradient filter using this 3x3 matrix: [ 1 2 -1 / 2 0 -2 / 1 -2 -1 ]. It gave a similar result to the edge detection. -We also tried unsharp filtering using this 3x3 matrix: [ -1 -1 -1 / -1 +

We also tried unsharp filtering using this 3x3 matrix: [ -1 -1 -1 / -1 8 -1 / -1 -1 -1 ]. This gave similar results to the edge detection too. -We started to suspect that the reason the 3x3 filters gave almost the +

We started to suspect that the reason the 3x3 filters gave almost the same result was that the fact that the spatial resolution of the thermal band is actually 4x4 pixels. Because of this, we tried with a 5x5 matrix, making sure it sums up to 0. - -1 -1 -1 -1 -1 - -1 -1 -1 -1 -1 - -1 -1 24 -1 -1 - -1 -1 -1 -1 -1 - -1 -1 -1 -1 -1 +

+ + + + + +
+
-1-1-1-1-1
-1-1-1-1-1
-1-124-1-1
-1-1-1-1-1
-1-1-1-1-1

Next, we tried some different weight: - -1 -1 -1 -1 -1 - -1 -2 -2 -2 -1 - -1 -2 32 -2 -1 - -1 -2 -2 -2 -1 - -1 -1 -1 -1 -1 +

+ + + + + +
-1-1-1-1-1
-1-2-2-2-1
-1-232-2-1
-1-2-2-2-1
-1-1-1-1-1

-This one gave more lines showing the borders between the thermal +

This one gave more lines showing the borders between the thermal pixels. From: shanette Dallyn