I want to read Arc/Info Binary Grids and convert them to other image formats using the C#-bindings of GDAL. I installed FWTools 2.4.7 and the current binaries (MSVC2010 (Win64) -stable) from here. Then I started testing the example C#-programs that are part of FWTools, especially GDALRead.cs and GDALReadDirect.cs. When I use the demo dataset utm.tif, this all works fine.
I then converted utm.tif to the Arc/Info Binary Grid format using ArcMap 10 (Conversion Tools - To Raster - Raster to other Format). When I try to use GDALRead.cs or GDALReadDirect.cs I get the following error messages:
GDALRead.cs:
Using driver Arc/Info Binary Grid
Band 1 :
DataType: GDT_Int16
Size (512,512)
PaletteInterp: GCI_Undefined
OverView 0 :
DataType: GDT_Int16
Size (256,256)
PaletteInterp: GCI_GrayIndex
OverView 1 :
DataType: GDT_Int16
Size (128,128)
PaletteInterp: GCI_GrayIndex
Non RGB images are not supported by this sample! ColorInterp = GCI_Undefined
GDALReadDirect.cs:
Using driver Arc/Info Binary Grid
Band 1 :
DataType: GDT_Int16
Size (512,512)
PaletteInterp: GCI_Undefined
OverView 0 :
DataType: GDT_Int16
Size (256,256)
PaletteInterp: GCI_GrayIndex
OverView 1 :
DataType: GDT_Int16
Size (128,128)
PaletteInterp: GCI_GrayIndex
The number of the raster bands is not enough to run this sample
This behavior is a bit surprising for me, as I did not change the dataset, I simply converted it into a new format. Any hints about the reasons for this behavior and how I can use GDAL via C# to convert ArcInfo binary grids to other image formats appreciated.
GDALReadDirect.cs has an erroneous method named SaveBitMapDirect, that first checks on the available Color interpretation and then on the number of bands. After the file is converted to Arc/Info binary Grid format, the information about the Color interpretation is lost, so only then the program checks on the number of available bands and returns an error message. SaveBitMapDirect works for the described case if Line 157 is edited:
if (redBand.GetRasterColorInterpretation() == ColorInterp.GCI_GrayIndex || redBand.GetRasterColorInterpretation() == ColorInterp.GCI_Undefined)
This is not a general fix, only for the immediate problem.
Related
I want to apply attention-ocr to detect all digits on number board of cars.
I've read your README.md of attention_ocr on github(https://github.com/tensorflow/models/tree/master/research/attention_ocr), and also the way I should do to use my own image data to train model with the StackOverFlow page.(https://stackoverflow.com/a/44461910/743658)
However, I didn't get any information of how to store annotation or label of the picture, or the format of this problem.
For object detection model, I was able to make my dataset with LabelImg and converting this into csv file, and finally make .tfrecord file.
I want to make .tfrecord file on FSNS dataset format.
Can you give me your advice to go on this training steps?
Please reread the mentioned answer it has a section explaining how to store the annotation. It is stored in the three features image/text, image/class and image/unpadded_class. The image/text field is used for visualization, some models support unpadded sequences and use image/unpadded_class, while the default version relies on the text padded with null characters to have the same length stored in the feature image/class. Here is the excerpt to store the text annotation:
char_ids_padded, char_ids_unpadded = encode_utf8_string(
text, charset, length, null_char_id)
example = tf.train.Example(features=tf.train.Features(
feature={
'image/class': _int64_feature(char_ids_padded),
'image/unpadded_class': _int64_feature(char_ids_unpadded),
'image/text': _bytes_feature(text)
...
}
))
If you have worked with tensorflow object detection, then the apporach should be much easier for you.
You can create the annotation file (in .csv format) using labelImg or any other annotation tool.
However, before converting it into tensorflow format (.tfrecord), you should keep in mind the annotation format. (FSNS format in this case)
The format is : files text xmin ymin xmax ymax
So while annotating dont bother much about the class (as you would have done in object detection !! Some random name should suffice.)
Convert it into .tfrecords.
And finally labelMap is a list of characters which you have annotated.
Hope it helps !
I'm currently using python 3.3 in combination with pyaudio and numpy. I took the example from the pyaudio website to play a simple wave file and send that data onto the default sound card.
Now I would like to change the volume of the audio, but when I multiply the array by 0.5, I get a lot of noise and distortion.
Here is a code sample:
while data != '':
decodeddata = numpy.fromstring(data, numpy.int16)
newdata = (decodeddata * 0.5).astype(numpy.int16)
stream.write(newdata.tostring())
data = wf.readframes(CHUNK)
How should I handle multiplication or division on this array without ruining the waveform?
Thanks,
It seemed that the source file's bitrate (24 bit) was not compatible with portaudio. After exporting to a 16 bit pcm file, the multiplication did not result in distortion.
To fix this for different typed files, it is necessary to check the bit depth and rescale correspondingly.
The goal is to validate an image based on dynamic height and width parameters, as well as DPI.
ImageMagick has the following command Identify which has a number of options.
-density
will generate the geometry widthxheight
-verbose
will generate a helpful "Print size: " and "Resolution"... among 78 other different lines... where width and height need to be parsed out to meet minimum requirements +/- 2%
so how does one extract those into a method, without stepping on intermediate toes (mini-magick)?
As the section on meta-information indicates, MiniMagick accesses the data using ImageMagick function in a single call, for example height density:
image["%y"]
ImageMagick has 47 single-letter attribute percent escapes that allows extraction of the data, provided your call to the image contains a ".path" suffix
image = MiniMagick::Image.open(#yourClass.theColumn.path)
i want to shrink png or jpg on OSX. i only want to shrinkg without affecting the image quality.
like tinypng.org
is there any recommended library? i just know imagemagick. is there a way to do that natively? or another library to shrink/compress images without affecting the image quality?
my aim is to shrink the file size, for example:
logo.png >> 476 k before shrink
logo.png >> 50k after shrink
Edit: to be clear, i want to compress the size of the file, not the image resolution.
TinyPNG.org works by using image quantisation - the similar colours in the image are converted into a HSV or RGB model and then merged depending on the distance.
How does it work?
...
When you upload a PNG (Portable Network Graphics) file, similar colours in your image are combined. This technique is called “quantisation”
...
src: http://tinypng.org
An answer here outlines a method of doing so: https://stackoverflow.com/a/492230/556479.
There are also some answers on this question with refer to how you can do so on Mac OS using objective-c: How do I reduce a bitmap to a known set of RGB colours
See Wikipedia for a more in depth guide: http://en.wikipedia.org/wiki/Color_quantization
Did you have a problem using ImageMagick? It has a rich set of quantize functions such as
bool MagickQuantizeImage( MagickWand mgck_wnd,
float number_colors,
int colorspace_type,
float treedepth,
bool dither,
bool measure_error )
Here is a very thorough guide to quantization using imageMagick
My suggestion is to use http://pngnq.sourceforge.net, it will give better results than ImageMagick and for the single example given in http://tinypng.org, it also produces a very similar output. It is a tiny C implementation of the method present in the paper "Kohonen Neural Networks for Optimal Colour Quantization". That alone is much better since you are no longer relying on closed unknown implementations.
Original (57 KB), tinypng.org (16 KB), pngnq (17 KB):
Using ImageMagick, the best quantization to 256 colors I can get uses the LAB colorspace and dithering by Floyd-Steinberg:
convert input.png -quantize LAB -dither FloydSteinberg -colors 256 output.png
This produces a 16 KB png, but it contains much more visual artifacts:
I try to import a raster file into my postgres database following this tutorial [http://www.postgis.org/documentation/manual-svn/using_raster.xml.html][1]
Environment: windows7, Postgres 8.4, postgis 2.0.
My command line are:
cd C:\Program Files (x86)\PostgreSQL\8.4\bin
raster2pgsql -s 4236 -I -G -M kiwi.jpg -F -t 100x100 public.gis > out.sql
psql -U postgres -d mydb2 -f out.sql
The picture named "kiwi" was in the "C:\Program Files (x86)\PostgreSQL\8.4\bin" folder.
The out.sql can be generated successfully. But after input "psql -U postgres -d mydb2 -f out.sql" , there is an error.
psql:out.sql:98: ERROR: syntax error at or near"Available"
LINE 1: Available GDAL raster formats:
Thank you!
This is the contents of the query:(I'm very new about postgis, so I can't figure out what's wrong here. Because I just follow the tutorial, it should work )
Available GDAL raster formats:
Virtual Raster
GeoTIFF
National Imagery Transmission Format
Raster Product Format TOC format
ECRG TOC format
Erdas Imagine Images (.img)
CEOS SAR Image
CEOS Image
JAXA PALSAR Product Reader (Level 1.1/1.5)
Ground-based SAR Applications Testbed File Format (.gff)
ELAS
Arc/Info Binary Grid
Arc/Info ASCII Grid
GRASS ASCII Grid
SDTS Raster
DTED Elevation Raster
Portable Network Graphics
JPEG JFIF
In Memory Raster
Japanese DEM (.mem)
Graphics Interchange Format (.gif)
Graphics Interchange Format (.gif)
Envisat Image Format
Maptech BSB Nautical Charts
X11 PixMap Format
MS Windows Device Independent Bitmap
SPOT DIMAP
AirSAR Polarimetric Image
RadarSat 2 XML Product
PCIDSK Database File
PCRaster Raster File
ILWIS Raster Map
SGI Image File Format 1.0
SRTMHGT File Format
Leveller heightfield
Terragen heightfield
USGS Astrogeology ISIS cube (Version 3)
USGS Astrogeology ISIS cube (Version 2)
NASA Planetary Data System
EarthWatch .TIL
ERMapper .ers Labelled
NOAA Polar Orbiter Level 1b Data Set
FIT Image
GRIdded Binary (.grb)
Raster Matrix Format
EUMETSAT Archive native (.nat)
Idrisi Raster A.1
Intergraph Raster
Golden Software ASCII Grid (.grd)
Golden Software Binary Grid (.grd)
Golden Software 7 Binary Grid (.grd)
COSAR Annotated Binary Matrix (TerraSAR-X)
TerraSAR-X Product
DRDC COASP SAR Processor Raster
R Object Data Store
Portable Pixmap Format (netpbm)
USGS DOQ (Old Style)
USGS DOQ (New Style)
ENVI .hdr Labelled
ESRI .hdr Labelled
Generic Binary (.hdr Labelled)
PCI .aux Labelled
Vexcel MFF Raster
Vexcel MFF2 (HKV) Raster
Fuji BAS Scanner Image
GSC Geogrid
EOSAT FAST Format
VTP .bt (Binary Terrain) 1.3 Format
Erdas .LAN/.GIS
Convair PolGASP
Image Data and Analysis
NLAPS Data Format
Erdas Imagine Raw
DIPEx
FARSITE v.4 Landscape File (.lcp)
NOAA Vertical Datum .GTX
NADCON .los/.las Datum Grid Shift
NTv2 Datum Grid Shift
ACE2
Snow Data Assimilation System
Swedish Grid RIK (.rik)
USGS Optional ASCII DEM (and CDED)
GeoSoft Grid Exchange Format
Northwood Numeric Grid Format .grd/.tab
Northwood Classified Grid Format .grc/.tab
ARC Digitized Raster Graphics
Standard Raster Product (ASRP/USRP)
Magellan topo (.blx)
SAGA GIS Binary Grid (.sdat)
Kml Super Overlay
ASCII Gridded XYZ
HF2/HFZ heightfield raster
OziExplorer Image File
USGS LULC Composite Theme Grid
Arc/Info Export E00 GRID
ZMap Plus Grid
NOAA NGS Geoid Height Grids
I have no idea about this error after searching a lot. I really appreciate that if you can give me some suggestions.
[1]: http://www.postgis.org/documentation/manual-svn/using_raster.xml.html
[2]: http://i.stack.imgur.com/YxjNJ.png
The psql utility in PostgreSQL is for processing SQL commands. The file you show doesn't contain SQL commands, it appears to contain information to help someone choose an option for the raster2pgsql program. A quick web search turned up documentation here:
http://www.postgis.org/documentation/manual-svn/using_raster.xml.html
Notice that the -G option is used to "Print the supported raster formats." The command line you used to run the program included that switch. If your goal is to produce SQL statements, that's not an option you should include. I don't know whether any other adjustments need to be made to your command, but you could start by dropping that and see what you get.