2
votes
1answer
25 views

How to do loops on raster cells with python console in QGIS?

I'm new here and beginner with python. I'm looking for a solution to my problem for some hours but now you are my last chance... I'm using the python (2.7.5) console in QGIS (2.4.0). Is there a ...
0
votes
1answer
35 views

Arcpy Subtracting rasters error - TypeError: 'unicode' object is not callable

I have a script which subtracts 2 versions of the same raster from each other (one newer than the other) and then extracts the additions & deletions that have happened. I created a simple test ...
-2
votes
0answers
30 views

Error 0100060 while running Extract by Points? [on hold]

The resources have not been much help here. I can run this same process hardcoded in the IDE, however through the tool dialogue it gives the following error? Any thoughts? ExecuteError: ERROR ...
0
votes
1answer
45 views

Calculate tree cover over certain area from raster data

Last year Hansen et al. published Global Forest Change map as set of raster data available in TIFF format. Basically those are 30-meters resolution satellite images with pixel values ranging from 0 ...
1
vote
1answer
58 views

Fix Black Border in Python Batch Raster Conversion

I have a Raster image like this as you can see the road are not connected between 2 raster (up and down) its because the scanned raster use different projection (dgn utm 50s) than my data frame (utm ...
2
votes
2answers
97 views

Calculate Slope Between Pixels Through Time: A Time Series Trend Analysis

I have a 9 year weekly time series (~500 raster grids of equal cell size and extent). I'm interested in obtaining the regression line slope between pixels (Imagine stacking all 500 grids on top of ...
0
votes
1answer
71 views

Iterative raster calculation script using NumPy arrays breaks after ~10 rasters, returns: “TypeError: Cannot create raster for numpy array.”

Here is my code: #Generate Cumulative Thresholds #5/15/14 import os import glob import arcpy import numpy as np #Enable overwriting output data arcpy.env.overwriteOutput = True ...
1
vote
1answer
64 views

Raster calculation in for loop returning exit code -1

I've put together a python script that does some calculations on rasters by converting them to NumPy arrays, doing the math, then converting them back to Raster and applying all the same spatial ...
0
votes
1answer
88 views

How to compare two rasters and reclass the greater value(python script)?

I am working on an assignment that requires us to reclass a raster(via python) from two rasters. We need to compare the power received at one cell(on raster1) and compare it to the same cell on raster ...
0
votes
1answer
61 views

Import raster into PostGIS using Python

I am trying to import information from a Bathymetric Attributed Grid (BAG) file into PostGIS using Python and psycopg2. I'm working, for now, on a Windows box with pre-compiled packages, so I don't ...
4
votes
1answer
77 views

How to automatically check for lidar flight line overlaps?

I have a series of lidar-based raster products created via FUSION. Since I am working with low density lidar data, many of the raster images show significant striping where lidar returns overlap on ...
1
vote
1answer
83 views

Geodjango read raster files

I am developing a web app in geodjango (django) framework but I need to import raster files. Is it possible a geodjango app read raster files from a directory? Thanks
1
vote
0answers
62 views

Problem with polygon overlay in raster stats using gdal

I am using the raster_stats module in python to calculate the mean carbon value for different sets of polygons. Here is the code that I am using: africa_sat = ...
0
votes
2answers
233 views

using Python to calculate NDVI, output as a Geotiff

I need a script that can calculate NDVI from two separate input Geotiff files, then output the results as a Geotiff. I wrote following script, most of which is borrowed from various on-line sources ...
3
votes
1answer
46 views

Why is Mosaic or Mosaic To New Image causing a 1-pixel gap between adjacent images?

I have a series of adjacent PNG images, and I'm trying to merge/mosaic them into a single seamless image. The images have clean "cuts" between them, with no overlaps. However, when I use either the ...
2
votes
2answers
89 views

ArcGIS - Extract by Attibutes in Model Builder

I have a model which at one point uses the Extract by Attributes tool to produce a new raster with just the areas containing the maximum values of the first. I would think that the SQL expression ...
2
votes
2answers
57 views

Update raster value to reflect total number of points within cell- python

I have what should be a fairly simple task, but I can't seem to figure out how to do it. I have to do it in python/arcpy/gdal/whatever because I'm trying to automate this process for a hundred or so ...
3
votes
1answer
44 views

How to obtain the width and height of an image using arcpy

This Stack Overflow question shows how to obtain the pixel dimensions of an image using Python. Is it possible to find an image's height and width using arcpy and ArcGIS? arcpy.Describe would seem ...
0
votes
1answer
88 views

Gdal creating raster rotated wrong way

I have been trying to read in a stack of images for a timeseries and created an output raster that contains the max pixel values of the timeseries. The arrays were created using numpy img_stack = ...
2
votes
2answers
81 views

raster standard deviation stretch python script

I am looking for ways of applying a permanent standard deviation stretch to rasters via python script. Are there any arcpy raster stretch functions? I was looking for a reference but could not find ...
1
vote
1answer
42 views

Extract information of a raster overlayed on another raster with a lower resolution directly in python

I have two aligned rasters with the same extent, one has a resolution of 5 meters and the other of 125 meters. I would like to place the 5 meter one over the 125 meter one and assign to these smaller ...
2
votes
2answers
374 views

How to extract X Y coordinates and RGB from pixels using python in QGIS?

I'm trying to white a Python plugin in QGIS (2.2) to get, for each pixel of a raster image, its X Y coordinates, as well as, its RGB (3 bands) values. At first I opened the raster file using: rlayer ...
1
vote
2answers
114 views

Mask image based on no-data pixels in another image with different projection - GDAL or Python

I've got a land cover image which covers the whole globe, and a satellite image which covers a very small part of the globe. These two images have different projections, co-ordinate systems and pixel ...
0
votes
0answers
19 views

Add a raster specifying the projection in pyqgis

I would like add an raster but I want to specify the projection. If I do : qgis.utils.iface.addRasterLayer(url,layerName) QGIS ask me to specify the projection. I want to this with python. How I ...
0
votes
0answers
28 views

Convert raster_stats list output to array / csv file

I usually program in R, but recently I have started to use python for most of my spatial programming. My python skills are still limited, and please excuse the simplicity of the question. I am ...
0
votes
2answers
291 views

Why am I getting 'Error 000732 Raster does not exist'?

I am trying to apply symbology to a raster layer via kernel density analysis. When I run the Python script below in ArcMap, I am get the error message below. I have searched and tried the common ...
2
votes
0answers
87 views

How to display images as cross sections in 3d

I want to display a base map and several vertical cross sections in 3D. The base map image is easy to rectify as a geotiff. How can I also display the cross sections? The cross sections are at ...
16
votes
5answers
573 views

How to buffer raster pixels by their values?

The pixels to the left represent tree locations and their associated crown radii (i.e. pixel values ranging from 2 - 5). I would like to buffer these raster pixels by their crown radius value. The ...
0
votes
2answers
195 views

Can you change the processing extent in environment settings using python to a shapefile?

I have managed to do this manually at Geoprocessing>Environments>Processing Extent and setting the shapefile in the drop down bar. I was wonder if this could be automated with a python script? My ...
1
vote
1answer
89 views

ListRasters not recognizing raster files in python

I have 2 rasters in my workspace, one in TIFF Format and the other in GRID format: "C:\ExampleFolder" When I use the python script: import arcpy >>> ...
1
vote
0answers
61 views

Write raster with its attribute table and symbology

I am classifying lots of rasters and I'd like to automate the legend creation and symbology displaying for easy manipulation. Here is the kind of raster I'm dealing with: library(raster) r <- ...
0
votes
2answers
69 views

Is it possible to alter raster values without Arcpy? [closed]

I'd like to be able to alter raster values, through fairly simple equations, without using the module Arcpy. Is that possible? It seems like gdal, numpy, and rasterlang might make this possible but ...
2
votes
0answers
36 views

Extract MultiValuesToPoints yields identical value for each band

I'm attempting to extract hyperspectral remote sensing data to a point featureclass using the ExtractMultiValuesToPoints ArcGIS tool. The value of each band (228 bands) should be appended as a field ...
1
vote
1answer
40 views

How to read the count of the cells with data with non “no-data” values ,in QGis?

How to read the count of the cells with data with non "no-data" values ,in QGis
7
votes
2answers
198 views

Finding specific pixel values ​​in ArcGIS using Python

I have a raster file containing some integer values. I need to find all pixels whose values are not defined in list like this one: l = [1,2,4,8,16,32,64,128]. Is there any easy way to solve that ...
4
votes
1answer
215 views

How to calculate total number of data cells in raster?

I am using ArcGIS 9.3 and python 2.5. My code is shown at the bottom of this post. I have a raster containing fire intensity information at 200m cell resolution. I run the script and the first count ...
1
vote
1answer
253 views

Convert polygons in shape file to a numpy array?

I have a shape file containing a number of polygons and all attributes being text. I'm trying to import the polygons into numpy as an array where each polygon is represented as unique values. I ...
3
votes
2answers
154 views

Using python to Raster clip the extent to be the same as the display?

I've been trying to figure this out for almost a week now. I am creating a tool which first needs the raster to be clipped out to the current display. I have tried all sorts of things. Below is the ...
0
votes
0answers
62 views

recording pixel value with Python script in ArcGIS 10.x

A scripting newbie question... I'd like to write a Python script for ArcGIS 10.x that would record the pixel value for all pixels in a raster. Furthermore, I'd like to only record a given value once ...
0
votes
0answers
37 views

recording pixel value with Python script in ArcGIS 10.x

A scripting newbie question... I'd like to write a Python script for ArcGIS 10.x that would record the pixel value for all pixels in a raster. Furthermore, I'd like to only record a given value once ...
5
votes
1answer
123 views

Is there a way to find out which pixel values are around the current pixel?

I would like to write a cycle which takes a current pixel, look at the surrounding pixels, choose the pixel with max/min value and skip to that pixel...and so on. Is there in arcpy such a function ...
0
votes
1answer
56 views

Retrieving raster/coverage width and height in pixels from GeoServer

Is it possible to retrieve the original width and height in pixels for a coverage in GeoServer using either the Python API or REST? I could not find anything in the documentation regarding how to ...
1
vote
1answer
41 views

How to build and pass remap for floating point raster without getting Reclassify ERROR 010255?

I am receiving the following message when executing my python script: ERROR 010255: String remap must be used with a string field. My input raster is floating point and I would like to ...
0
votes
0answers
82 views

QGIS 2.0 change the raster band from python command

Does anyone know how to change the band of a multiband raster from the python command line in QGIS2.0? It used to be done with something like rLayer.setGrayBandName(1) in 1.8, but this is no longer a ...
3
votes
0answers
337 views

GDAL polygonize lines

I have a raster file containing roads (left image). I polygonize the raster file with GDAL (see the script below). In the end I like to have vector lines. However GDAL only gives me something like ...
1
vote
1answer
180 views

GDAL polygonize only certain raster values

I want to polygonize a raster file with GDAL. I only want to rasterize cells with a value of 0. Is it possible to specify that within the polygonize function or do I have to modify my raster before ...
2
votes
1answer
107 views

Arcpy.GetRasterProperties_management values do not match values found via ArcCatalog or ArcView

I am using Arcpy to extract the mean and standard deviation values of tiff Landsat satellite images and I get very high values. Values in the thousands rather than in the low hundreds! If I look at ...
1
vote
0answers
27 views

Map algebra from QGIS python console? [duplicate]

What command do I use to do map algebra on rasters from the QGIS python console?
0
votes
1answer
127 views

How to add raster data to Table of Contents using python?

I can easily add shapefiles to the Table of Contents in Arcmap using the following codes: mxd = arcpy.mapping.MapDocument("current") df = arcpy.mapping.ListDataFrames(mxd, "Layers")[0] path = ...
1
vote
3answers
509 views

Is it possible to open rasters as array in NumPy without using another library?

I know that it is possible to open a raster as an array in NumPy using GDAL, but I want to skip GDAL and use NumPy only, as it is cooler handling rasters with NumPy as matrices. There is a similar ...