Dear shailesh
I am not sure if you are asking how to take the samples of similar pixeles or if you are asking how to do a mask ... the process in PCI is similar. To do a mask of a region and to extract this region of the Supervised classification, first you have to create a layer type BMP in the file of the image that you are working and then work with the polygon tools ( you can find squares, rectangles, circles, and the seed sampling that take similar pixels in accordance with certain parameters that you decide). Then when you will aply the algorithm of the Supervised classification you can choose -in the dialogue box- that the algorithm is applied only to the area that is under the mask.
On the other hand, if you want to take samples of similar pixels...working inside the environment of a supervised classification, you only need to follow the process
to choose each class that you want to find -obviously the process leads you to working with the same tool of polygons to choose the samples, but you don´t have to create a layer different because all that is working at the layer of the supervised classification-. If you have already a supervised classification why don´t you try to do a post-clasification process?...the name is class aggregation, and if you make the mask (in a BMP layer) you can add class of the areas that are under the mask.
anyway..i was working with images in format PIX or geotiff..then i´m not sure if a jpg image be able to be worked by this process. I think that you Might try to convert the image to PIX or in a program of edition of images (type photoshop) you might divide it in channels and then to record it in PCI as PIX...
I hope that this should help you in something
Cheers
Maria del Mar Rendón Orduz
GIS and Remote Sensing Specialist
Consultant- Instituto Amazónico de Investigaciones Científicas SINCHI
Clle 20 # 5-44 /57(1)2835567
Bogotá-Colombia
--- Begin Message ---
- To: discuss@xxxxxxxxxxxxxxxx
- Subject: Doing Masking operation with PCI..
- From: "shailesh gavathe" <shail_79@xxxxxxxxxxx>
- Date: Mon, 14 Mar 2005 23:09:15 -0500
- Reply-to: discuss@xxxxxxxxxxxxxxxx
Hi all group Members,
This is really a nice discussion group for PCI Geomatica Software and its functions.
I do have one simple question regarding "Masking" operation with PCI Geomatica Software.
Firstly my image is in Jpeg format.
I want to clip one area which has most of the colors and those are Land fetures on my image.
I want to clip that area and assign the same pixel values to all colors standing in the same featrures(i.e. same statistics).
i know that we can perform Masking after supervised classification,
But is there anyway we can perform masking after Unsupervised classification.
I tried with PCI, But i could not find any solution.
I would deeply appreciate, if someone can let me the solution
because i m trying since last week begining,but i am getting frustrated more when i m working on it.
Sincerely,
shailesh
516, St Johns Street,Apt# 102,Ypsilanti,MI-48197,USA.
Res No. 734-482-0832
--- End Message ---