A commonly used method of lossy compression for photographic images

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Georeferencing jpg via Gdal_translate output a GIS tif 15.5 times bigger [duplicate]

Given as input a light 874kb jpg, I use gdal_translate -a_ullr (source) to reinject GIS georeferencing : -a_ullr ulx uly lrx lry : Assign/override the georeferenced bounds of the output file. ...
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332 views

multiple graphics added to ArcGIS javascript API map are not printing (using MapExport) reliably

I combined samples for Printing with graphics https://developers.arcgis.com/javascript/jssamples/widget_print.html and labeling ...
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53 views

QGIS processing does not support jpg

I would like to work with the gdal functions provided in the processing toolbox. It is easy to call: import processing processing.alglist() ...
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80 views

How to choose a coordinate reference system

I have a jpeg image of a reserve's layout and would like to use it to plot animals movements on i.e. GPS points. I have no idea which coordinate reference system to choose during the "georeferencing" ...
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55 views

Saving Map on Server Side as Image File

I am trying to save my openlayers map on the server, following these instructions, the sections Client-side: Tile collection and Server side: PHP: ...
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17 views

Large Jpegs, handling in ARCGIS

I am working with 10s of large raster data, each one is from jpeg, around 65000x22000 pixels, I have a normal laptop, with 8 Gb of RAM and i5 processor. Can any one give me guidance on how do i make ...
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44 views

Where can i find Shapefiles of city along with the world file (.jgw) and the jpg image?

Are there any links where i can download a shapefile of a certain city along with aerial view jpeg image and the corresponding world file (.jgw) ? I need it to test an algorithm. Thanks,
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Shape file generation [duplicate]

Is it possible to generate a shape file with lines and polygons using only the image for which it has to be generated ? I need the lines,polygons feautres of the shape file in an algorithm which i am ...
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113 views

GDAL TIF to JPG Creates Dark Image

I'm using the GDAL Raster>Translate to create JPGs from Georeferenced TIFs. The translation is working, but the resulting JPGs are significantly darker than the TIFs they are being created from. ...
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Why do text boxes and arrows shift position when exported from print composer to jpeg QGIS 2.2

I have created a map using a 1:20000 WMS layer. On top of this I created a shapefile layer tracing a mapped stream. In print composer I added a couple of text boxes with arrows pointing to certain ...
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195 views

Can you use a large file directory of jpgs for without georeferencing

I have a large map data set of 256x256 jpg images. The file directory is organized by /map_type/zoom/x/y.jpg. I have 12 zoom levels and each zoom level directory has 2^(2*zoom level) images. I have ...
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581 views

can't add JPG files into QGIS?

I can't add JPG files into QuantumGIS. I get an error message "C:\Spatial_Days\Data\Working\AP_Coast_Export.jpg is not a supported raster data source". I am using QGIS 1.7.4 Wroclaw with GDAL 1.8.1 ...