Hi Dai, I think you will need first to find information about your TIFF file before trying to read its data, use the QUERY_TIFF function. Cheers, fernando

Hi, I try query_tiff and failed. IDL> ok = query_tiff('D:\15.tiff',info) % Loaded DLM: TIFF. IDL> print,ok 0

Hi Dai, This is saying that IDL doesn't know this file as a TIFF file format. Can you re-generate the file again, in case is corrupted?. If you get 1 from the query, then you can use the following structure information to get information of the file: http://www.exelisvis.com/...#Q_815714925_1072337 Cheers, fernando

HI,Fernando I'm a colleague of Dai. If use query_tiff, it still return 0. I got a friend of mine who use IDL(8.2) on a mac, with simple " read_tiff('18.tif') ", she can get data read.(we have tried idl 8.2.3 on win7(32), failed...) but if she use query_tiff, she still get 0 return. It is very weird. I am wondering if it has something to do with tiff library. I will try upload one sample tiff file in dropbox, hope you can help us. Thank you very much.

Hi,Fernando Please find the sample tif file here: https://www.dropbox.com/s/4xz32rsiseyzabk/test.tif for further information in this file it has only one layer,which is 7200*3600, and the data is arranged in 16-bit unsigned ints Thank you again for your time

here are some tiff dump info IDL> tiff_dump,'test.tif' % Compiled module: TIFF_DUMP. Tiff File: byte order=II, Version = 42 *** IFD 0 starting at offset: 8 14 directory entries ImageWidth (256)UShort = 7200 ImageLength (257)UShort = 3600 BitsPerSample (258)UShort = 16 Compression (259)UShort = 8 PhotometricInterpretation (262)UShort = 1 StripOffsets (273)ULong = 29054 30176 31284 32431 33544 34698 35835 36969 38119 39292 40463 41675 42896 44126 45355 46592 SamplesPerPixel (277)UShort = 1 RowsPerStrip (278)UShort = 1 StripByteCounts (279)ULong = 1122 1108 1147 1113 1154 1137 1134 1150 1173 1171 1212 1221 1230 1229 1237 1263 PlanarConfiguration (284)UShort = 1 Predictor (317)UShort = 2 SampleFormat (339)UShort = 1 (33550)Double = 0.050000000 0.050000000 0.00000000 (33922)Double = 0.00000000 0.00000000 0.00000000 -180.00000 90.000000 0.00000000 IDL>

Dear Jian, Are you affiliated with Nanjing University? I think at this point it will be better if you can contact the IDL support in China. The email is: shanic@esrichina.com.cn I think it will be more efficient that way. Thank you! Fernando

HI there The Tagged Image File Format (known as TIFF) is a bitmapped and lossless image format, which is often used to store large but high-quality images. Besides, a multi-page TIFF file may contain several images.So i usually read the tiff files using this professional TIFF file processing software development kit (SDK), which can hel manipulate and deal with TIFF file from various aspects.