| image cutting, [message #28439] |
Sat, 15 December 2001 08:52  |
dinhnq
Messages: 14
Registered: December 2001
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Junior Member |
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Dear lists,
I have 12 satellite images 1000*1000 pixels in HDF file for the same
region. I want to cut 200*200 from colum 400 row 400. And put all 12
pieces in same file. Any one can help!
Many thanks in advance,
Dinh Huong
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| Re: image cutting, [message #28587 is a reply to message #28439] |
Thu, 20 December 2001 10:30  |
dinhnq
Messages: 14
Registered: December 2001
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Junior Member |
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Hi Leon Majewski,
Thank you very much for your response.
In fact, my data is a set of landsat images (can be in both .tiff anf
.hdf format) in seprate files.
I want to do some classification (in smaller area) but in ENVI I can�t
see any function can do this with seprate files. So I have to put 6
bands together in one file. The output file can be any type that can
read by ENVI.
Because I just begin learning IDL a week before so it take time to
understand your codes.
When I run "Test_HDF_Cropping_GenData", there is a message
"HDF_SD_START: Unable to start the HDF-SD interface"
When I run "Test_HDF_Cropping", the message is "Execution halted at:
HDF_CROPPING 19 E:\IDLPRO\HDF_Cropping.pro
% TEST_HDF_CROPPING 87
E:\IDLPRO\HDF_Cropping.pro" and stop at line
"HDF_SD_GETINFO,sds_id_i,NAME=NAME"
I don�t know which file(s) below have to be in working directory
before running progam:
Filename = 'C:\test2.hdf'
oFilename= 'C:\test2sm.hdf'
Filename = 'MyLargeFile.hdf'
oFilename= 'MySmallFile.hdf'
And I wrote few lines to make a multi-channel image from seprate band
like this. It works with 3 bands, but it doens�t works with 6 bands.
Could you explain for me why?
===========
PRO Composite, Red=red, Green=green, Blue=blue
cd, 'e:\IDLPRO\'
band1 = READ_TIFF('tm1.tiff')
band2 = READ_TIFF('tm2.tiff')
band4 = READ_TIFF('tm4.tiff')
WRITE_TIFF, 'multi3.tif', red=band1, green=band2, blue=band4,
PLANARCONFIG=2
END
===========
PRO Composite6, ba1=ba1, ba2=ba2, ba3=ba3, ba4=ba4, ba5=ba5, ba7=ba7
cd, 'e:\IDLPRO\'
b1 = READ_TIFF('tm1.tiff')
b2 = READ_TIFF('tm2.tiff')
b3 = READ_TIFF('tm3.tiff')
b4 = READ_TIFF('tm4.tiff')
b5 = READ_TIFF('tm5.tiff')
b7 = READ_TIFF('tm7.tiff')
WRITE_TIFF, 'multi6.tif', ba1=b1, ba2=b2, ba3=b3 , ba4=b4, ba5=b5,
ba7=b7 ; PLANARCONFIG=1
END
Many thanks again,
Huong Dinh
>
> Hi Dinh
>
> You might need to provide a little more information. HDF files can store
> a wide variety of information types - each needing to be accessed in
> it's own special way.
> My guess is that you want to access a scientific data set (SDS; ie use
> the SD interface) and crop this to a 200x200 segment. Then store this in
> a new HDF file as an SDS.
>
> A couple of questions arise:
> a) is the data you are trying to access an SDS?
> b) is the original data set all in one block (12x1000x1000) or separate
> SDSs?
> c) does the output file need to be HDF (see d)
> d) is there any meta-data that is required to be copied from the
> original file to the output file
> e) ...
>
>
> Anyway, here is a program (included below - limited error checking /
> testing / thinking ;�) ) to get you started. The main points in this
> are:
>
> a) the START and COUNT keywords to HDF_SD_GETDATA:
> HDF_SD_GETDATA, sds_id_i, SmallDataSet, START=Offset, COUNT=SegSize
>
> b) the writting of data to an HDF file:
> new_sds_id = HDF_SD_CREATE(sd_oid, $
> string('sub '+NAME), size(SmallDataSet, /dimensions))
> HDF_SD_ADDDATA, new_sds_id, SmallDataSet
>
> c) you need to know the index numbers of the original 12 data sets:
> Get_SDSs = [0,1,2,3,4,5,6,7,8,9,10,11]
>
> Leon
>
> ;================================================
>
> FUNCTION HDF_Cropping, inFilename, outFilename, $
> Offset, SegSize, Get_SDSs
>
> ;Open the HDF file in SD read mode
> sd_id = HDF_SD_START(inFilename, /READ)
>
> ;Find out any some about the file
> HDF_SD_FILEINFO,sd_id,NumSDS,attributes
> IF NumSDS GE 1 THEN BEGIN
> ;If there are SDs found in the file, create an output file
> sd_oid = HDF_SD_START(outFilename, /CREATE)
>
> FOR i = 0, n_elements(Get_SDSs)-1 DO BEGIN
> ;Select the i^th data set (from the Get_SDSs above)
> sds_id_i = HDF_SD_SELECT(sd_id, Get_SDSs[i])
> If sds_id_i[0] ne 0 then begin
>
> ;Retrieve the data segment
> HDF_SD_GETINFO,sds_id_i,NAME=NAME
> HDF_SD_GETDATA, sds_id_i, SmallDataSet, $
> START=Offset, COUNT=SegSize
> ;End access to the dataset
> HDF_SD_ENDACCESS, sds_id_i
>
> ;Now that the data segment has been obtained, store it:
> new_sds_id = HDF_SD_CREATE(sd_oid, $
> string('sub '+NAME), $
> size(SmallDataSet, /dimensions))
> HDF_SD_ADDDATA, new_sds_id, SmallDataSet
>
> HDF_SD_ENDACCESS, new_sds_id
> ENDIF
> ENDFOR
>
> ;Close the output file
> HDF_SD_END, sd_oid
> ;Close the input file
> HDF_SD_END,sd_id
> ;Return to the calling program letting it know everything went ok
> RETURN, 1
> ENDIF
>
> HDF_SD_END,sd_id
> RETURN, 0
> END
>
> ;================================================
>
> PRO Test_HDF_Cropping_GenData
> Filename = 'C:\test2.hdf'
> oFilename= 'C:\test2sm.hdf'
>
> StartPos = [400,400]
> ImageSize= [200,200]
>
> ;generate the test data file:
> TestData = dist(1000)
>
> sd_oid = HDF_SD_START(Filename, /CREATE)
> new_sds_id = HDF_SD_CREATE(sd_oid, 'My Test Data', $
> size(TestData, /dimensions))
> HDF_SD_ADDDATA, new_sds_id, TestData
> HDF_SD_ENDACCESS, new_sds_id
> HDF_SD_END, sd_oid
>
> ;Make an array that holds the index of the data set to be subsampled
> Get_SDSs = [0,0,0,0]
>
> Result = HDF_Cropping(Filename, oFilename, $
> StartPos, ImageSize, Get_SDSs)
> a = hdf_browser(oFilename)
> END
>
> ;================================================
>
> PRO Test_HDF_Cropping
> Filename = 'MyLargeFile.hdf'
> oFilename= 'MySmallFile.hdf'
>
> StartPos = [400,400]
> ImageSize= [200,200]
>
> ;Make an array that holds the index of the data set to be subsampled
> Get_SDSs = [0,1,2,3,4,5,6,7,8,9,10,11]
>
> Result = HDF_Cropping(Filename, oFilename, $
> StartPos, ImageSize, Get_SDSs)
> a = hdf_browser(oFilename)
> END
>
> ;================================================
>
> -------------------------
> Leon Majewski
>
> Remote Sensing & Satellite Research Group
> Curtin University of Technology, Perth, Australia
>
> email: majewski@ses.curtin.edu.au
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| Re: image cutting, [message #28603 is a reply to message #28439] |
Thu, 20 December 2001 05:20 |
majewski
Messages: 15
Registered: March 2000
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Junior Member |
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On 15 Dec 2001 08:52:43 -0800, dinhnq@yahoo.com (Dinh Huong) wrote:
> I have 12 satellite images 1000*1000 pixels in HDF file for the same
> region. I want to cut 200*200 from colum 400 row 400. And put all 12
> pieces in same file. Any one can help!
Hi Dinh
You might need to provide a little more information. HDF files can store
a wide variety of information types - each needing to be accessed in
it's own special way.
My guess is that you want to access a scientific data set (SDS; ie use
the SD interface) and crop this to a 200x200 segment. Then store this in
a new HDF file as an SDS.
A couple of questions arise:
a) is the data you are trying to access an SDS?
b) is the original data set all in one block (12x1000x1000) or separate
SDSs?
c) does the output file need to be HDF (see d)
d) is there any meta-data that is required to be copied from the
original file to the output file
e) ...
Anyway, here is a program (included below - limited error checking /
testing / thinking ;�) ) to get you started. The main points in this
are:
a) the START and COUNT keywords to HDF_SD_GETDATA:
HDF_SD_GETDATA, sds_id_i, SmallDataSet, START=Offset, COUNT=SegSize
b) the writting of data to an HDF file:
new_sds_id = HDF_SD_CREATE(sd_oid, $
string('sub '+NAME), size(SmallDataSet, /dimensions))
HDF_SD_ADDDATA, new_sds_id, SmallDataSet
c) you need to know the index numbers of the original 12 data sets:
Get_SDSs = [0,1,2,3,4,5,6,7,8,9,10,11]
Leon
;================================================
FUNCTION HDF_Cropping, inFilename, outFilename, $
Offset, SegSize, Get_SDSs
;Open the HDF file in SD read mode
sd_id = HDF_SD_START(inFilename, /READ)
;Find out any some about the file
HDF_SD_FILEINFO,sd_id,NumSDS,attributes
IF NumSDS GE 1 THEN BEGIN
;If there are SDs found in the file, create an output file
sd_oid = HDF_SD_START(outFilename, /CREATE)
FOR i = 0, n_elements(Get_SDSs)-1 DO BEGIN
;Select the i^th data set (from the Get_SDSs above)
sds_id_i = HDF_SD_SELECT(sd_id, Get_SDSs[i])
If sds_id_i[0] ne 0 then begin
;Retrieve the data segment
HDF_SD_GETINFO,sds_id_i,NAME=NAME
HDF_SD_GETDATA, sds_id_i, SmallDataSet, $
START=Offset, COUNT=SegSize
;End access to the dataset
HDF_SD_ENDACCESS, sds_id_i
;Now that the data segment has been obtained, store it:
new_sds_id = HDF_SD_CREATE(sd_oid, $
string('sub '+NAME), $
size(SmallDataSet, /dimensions))
HDF_SD_ADDDATA, new_sds_id, SmallDataSet
HDF_SD_ENDACCESS, new_sds_id
ENDIF
ENDFOR
;Close the output file
HDF_SD_END, sd_oid
;Close the input file
HDF_SD_END,sd_id
;Return to the calling program letting it know everything went ok
RETURN, 1
ENDIF
HDF_SD_END,sd_id
RETURN, 0
END
;================================================
PRO Test_HDF_Cropping_GenData
Filename = 'C:\test2.hdf'
oFilename= 'C:\test2sm.hdf'
StartPos = [400,400]
ImageSize= [200,200]
;generate the test data file:
TestData = dist(1000)
sd_oid = HDF_SD_START(Filename, /CREATE)
new_sds_id = HDF_SD_CREATE(sd_oid, 'My Test Data', $
size(TestData, /dimensions))
HDF_SD_ADDDATA, new_sds_id, TestData
HDF_SD_ENDACCESS, new_sds_id
HDF_SD_END, sd_oid
;Make an array that holds the index of the data set to be subsampled
Get_SDSs = [0,0,0,0]
Result = HDF_Cropping(Filename, oFilename, $
StartPos, ImageSize, Get_SDSs)
a = hdf_browser(oFilename)
END
;================================================
PRO Test_HDF_Cropping
Filename = 'MyLargeFile.hdf'
oFilename= 'MySmallFile.hdf'
StartPos = [400,400]
ImageSize= [200,200]
;Make an array that holds the index of the data set to be subsampled
Get_SDSs = [0,1,2,3,4,5,6,7,8,9,10,11]
Result = HDF_Cropping(Filename, oFilename, $
StartPos, ImageSize, Get_SDSs)
a = hdf_browser(oFilename)
END
;================================================
-------------------------
Leon Majewski
Remote Sensing & Satellite Research Group
Curtin University of Technology, Perth, Australia
email: majewski@ses.curtin.edu.au
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| Re: image cutting, [message #28604 is a reply to message #28439] |
Thu, 20 December 2001 04:29 |
R.Bauer
Messages: 1424
Registered: November 1998
|
Senior Member |
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Dinh Huong wrote:
>
> Dear lists,
>
> I have 12 satellite images 1000*1000 pixels in HDF file for the same
> region. I want to cut 200*200 from colum 400 row 400. And put all 12
> pieces in same file. Any one can help!
>
> Many thanks in advance,
>
> Dinh Huong
Normally this could be selected by the count and start keywords of
HDF_SD_GETDATA
HDF_SD_GETDATA, SDS_ID, Data [, COUNT=vector] [, /NOREVERSE] [,
START=vector] [, STRIDE=vector]
Reimar
--
Reimar Bauer
Institut fuer Stratosphaerische Chemie (ICG-1)
Forschungszentrum Juelich
email: R.Bauer@fz-juelich.de
http://www.fz-juelich.de/icg/icg1/
============================================================ ======
a IDL library at ForschungsZentrum Juelich
http://www.fz-juelich.de/icg/icg1/idl_icglib/idl_lib_intro.h tml
http://www.fz-juelich.de/zb/text/publikation/juel3786.html
============================================================ ======
read something about linux / windows
http://www.suse.de/de/news/hotnews/MS.html
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