/*
* Retrieve geospatial reference information from a GeoPDF document
*
* This pCOS sample searches for several different kinds of geospatial
* information: three Flavors according to Adobe PDF 1.7 extension level 3
* (these are equivalent to ISO 32000-2), and the proprietary TerraGo format:
*
* (1) Page-based ISO viewports
*
* This flavor can be created with Acrobat by manually adding geospatial
* reference information to a page. In PDFlib it can be created with the
* "viewports" option of PDF_begin/end_page_ext().
*
* (2) Image-based ISO viewports
*
* This flavor can be created with Acrobat by converting raster images (e.g.
* GeoTIFF) to PDF. In PDFlib it can be created with the "georeference" option
* of PDF_load_image().
*
* (3) XObject-based ISO viewports
*
* This flavor is specified in ISO as well, but unfortunately it doesn't work in
* Acrobat DC. It could be created with PDFlib, but this feature is disabled
* since the resulting GeoPDF documents wouldn't work in Acrobat.
*
* (4) Page-based geospatial information created by TerraGo.
*
* This flavor is created by the TerraGo software and is accepted by Acrobat
* in addition to the ISO flavors.
*
* Required software: pCOS interface 8 (PDFlib+PDI/PPS 9, TET 4.1, PLOP 5.0)
* Required data: PDF document with geospatical information
*/
package com.pdflib.cookbook.pcos.interactive;
import com.pdflib.IpCOS;
import com.pdflib.cookbook.pcos.pcos_cookbook_example;
public class geospatial extends pcos_cookbook_example {
/* This is where the data files are. Adjust as necessary. */
private final static String SEARCH_PATH = "../input";
public void example_code(IpCOS p, int doc) throws
Exception {
String path;
String basepath;
String objtype;
System.out.println("File name: " + p.pcos_get_string(doc, "filename"));
int pagecount = (int) p.pcos_get_number(doc, "length:pages");
for (int page = 0; page < pagecount; page++) {
System.out.println("page " + (page + 1) + ": ");
/*
* ************************************************************
* (1) Page-based ISO viewports
* ************************************************************
*/
/* Iterate over all viewports which may be present on the page */
basepath = "pages[" + page + "]/VP";
int vpcount = (int) p.pcos_get_number(doc, "length:" + basepath);
for (int v = 0; v < vpcount; v++) {
System.out.println(" ISO viewport " + v + " on page:");
dump_iso_viewport(p, basepath + "[" + v + "]", doc);
}
/*
* ************************************************************
* (2) Image-based ISO viewports
* ************************************************************
*/
/* Iterate over all images on the page */
basepath = "pages[" + page + "]/images";
int imagecount = (int) p.pcos_get_number(doc, "length:" + basepath);
for (int image = 0; image < imagecount; image++) {
path = basepath + "[" + image + "]/Measure/Subtype";
objtype = p.pcos_get_string(doc, "type:" + path);
if (objtype.equals("name")) {
String subtype = p.pcos_get_string(doc, path);
if (subtype.equals("GEO")) {
System.out.println(" ISO viewport on image " + image
+ ": ");
basepath = "pages[" + page + "]/images[" + image + "]";
dump_iso_viewport(p, basepath, doc);
}
}
}
/*
* ************************************************************
* (3) XObject-based ISO viewports
* ************************************************************
*/
/* Iterate over all Form XObjects on the page */
basepath = "pages[" + page + "]/Resources/XObject";
int xobjcount = (int) p.pcos_get_number(doc, "length:" + basepath);
for (int xobj = 0; xobj < xobjcount; xobj++) {
String subtype = p.pcos_get_string(doc, basepath + "[" + xobj
+ "]/Subtype");
/* Consider Form XObjects only (as opposed to Image XObjects */
if (subtype.equals("Form")) {
path = basepath + "[" + xobj + "]/Measure/Subtype";
objtype = p.pcos_get_string(doc, "type:" + path);
if (objtype.equals("name")) {
subtype = p.pcos_get_string(doc, path);
if (subtype.equals("GEO")) {
System.out.println(" viewport on Form XObject "
+ xobj + ": ");
basepath = "pages[" + page + "]/images[" + xobj
+ "]";
dump_iso_viewport(p, basepath, doc);
}
}
}
}
/*
* ************************************************************
* (4) Page-based TerraGo viewports
* ************************************************************
*/
/*
* Iterate over all TerraGo viewports which may be present on the
* page
*/
path = "pages[" + page + "]/LGIDict";
int tgcount = (int) p.pcos_get_number(doc, "length:" + path);
for (int tg = 0; tg < tgcount; tg++) {
System.out.println(" TerraGo viewport " + tg + ": ");
basepath = path + "[" + tg + "]";
dump_terrago_viewport(p, basepath, doc);
}
}
}
/* Emit some ISO viewport properties; can easily be extended */
private void dump_iso_viewport(IpCOS p, String basepath, int doc)
throws Exception {
String path;
String objtype;
path = basepath + "/Measure/GCS/WKT";
objtype = p.pcos_get_string(doc, "type:" + path);
if (objtype.equals("string")) {
System.out
.println(" WKT='" + p.pcos_get_string(doc, path) + "'");
}
path = basepath + "/Measure/GCS/EPSG";
objtype = p.pcos_get_string(doc, "type:" + path);
if (objtype.equals("number")) {
System.out
.println(" EPSG=" + (int) p.pcos_get_number(doc, path));
}
/* Print the world coordinates for two points */
path = basepath + "/Measure/GCS/GPTS[0]";
System.out.println(" lat,lon="
+ p.pcos_get_number(doc, basepath + "/Measure/GPTS[0]") + ","
+ p.pcos_get_number(doc, basepath + "/Measure/GPTS[1]") + " to "
+ p.pcos_get_number(doc, basepath + "/Measure/GPTS[4]") + ","
+ p.pcos_get_number(doc, basepath + "/Measure/GPTS[5]"));
}
/* Emit some TerraGo viewport properties; can easily be extended */
private void dump_terrago_viewport(IpCOS p, String basepath, int doc)
throws Exception {
String path;
String objtype;
path = basepath + "/Description";
objtype = p.pcos_get_string(doc, "type:" + path);
if (objtype.equals("string")) {
System.out.println(" description='"
+ p.pcos_get_string(doc, path) + "'");
}
path = basepath + "/Display/Datum";
objtype = p.pcos_get_string(doc, "type:" + path);
if (objtype.equals("string")) {
System.out.println(" display datum='"
+ p.pcos_get_string(doc, path) + "'");
}
path = basepath + "/Projection/ProjectionType";
objtype = p.pcos_get_string(doc, "type:" + path);
if (objtype.equals("string")) {
System.out.println(" projection type='"
+ p.pcos_get_string(doc, path) + "'");
}
}
public geospatial(String[] argv, String readable_name, String search_path) {
super(argv, readable_name, search_path);
}
public static void main(String argv[]) {
geospatial example = new geospatial(argv, "Geospatial data",
SEARCH_PATH);
example.execute();
}
}
