Getting PDF page length
0
In my articles which formatted PDF, one or more pages may be blanked and I want to detect them and remove from PDF file. If I can identify pages that are less than 60 KB, I think I can detect the pages that are empty. Because they're probably empty.
I tried like this:
var reader = new PdfReader("D:\_test\file.pdf");
/*
* With reader.FileLength, I can get whole pdf file size.
* But I dont know, how can I get pages'sizes...
*/
for (var i = 1; i <= reader.NumberOfPages; i++)
{
/*
* MessageBox.Show(???);
*/
}
c# itext page-size
asked Nov 22 at 17:46
Colin Henricks
94152245
add a comment |
0
In my articles which formatted PDF, one or more pages may be blanked and I want to detect them and remove from PDF file. If I can identify pages that are less than 60 KB, I think I can detect the pages that are empty. Because they're probably empty.
I tried like this:
var reader = new PdfReader("D:\_test\file.pdf");
/*
* With reader.FileLength, I can get whole pdf file size.
* But I dont know, how can I get pages'sizes...
*/
for (var i = 1; i <= reader.NumberOfPages; i++)
{
/*
* MessageBox.Show(???);
*/
}
c# itext page-size
asked Nov 22 at 17:46
Colin Henricks
94152245
1
How about splitting the PDF into multiple PDFs, one for each page and then measure their respective sizes?
– Uwe Keim
Nov 23 at 8:25
@uweKeim, I don't want to split PDF file page by page. Because think about what would be useful for me if I splited a storybook page by page. It didn't sound professionally to reassemble the page after splitting the pages page by page and removing the blank pages.
– Colin Henricks
Nov 23 at 14:59
add a comment |
0
0
0
In my articles which formatted PDF, one or more pages may be blanked and I want to detect them and remove from PDF file. If I can identify pages that are less than 60 KB, I think I can detect the pages that are empty. Because they're probably empty.
I tried like this:
var reader = new PdfReader("D:\_test\file.pdf");
/*
* With reader.FileLength, I can get whole pdf file size.
* But I dont know, how can I get pages'sizes...
*/
for (var i = 1; i <= reader.NumberOfPages; i++)
{
/*
* MessageBox.Show(???);
*/
}
c# itext page-size
asked Nov 22 at 17:46
Colin Henricks
94152245
In my articles which formatted PDF, one or more pages may be blanked and I want to detect them and remove from PDF file. If I can identify pages that are less than 60 KB, I think I can detect the pages that are empty. Because they're probably empty.
I tried like this:
var reader = new PdfReader("D:\_test\file.pdf");
/*
* With reader.FileLength, I can get whole pdf file size.
* But I dont know, how can I get pages'sizes...
*/
for (var i = 1; i <= reader.NumberOfPages; i++)
{
/*
* MessageBox.Show(???);
*/
}
c# itext page-size
c# itext page-size
asked Nov 22 at 17:46
Colin Henricks
94152245
asked Nov 22 at 17:46
Colin Henricks
94152245
edited Nov 23 at 15:04
asked Nov 22 at 17:46
Colin Henricks
94152245
asked Nov 22 at 17:46
Colin Henricks
94152245
asked Nov 22 at 17:46
Colin Henricks
94152245
94152245
1
How about splitting the PDF into multiple PDFs, one for each page and then measure their respective sizes?
– Uwe Keim
Nov 23 at 8:25
@uweKeim, I don't want to split PDF file page by page. Because think about what would be useful for me if I splited a storybook page by page. It didn't sound professionally to reassemble the page after splitting the pages page by page and removing the blank pages.
– Colin Henricks
Nov 23 at 14:59
add a comment |
1
How about splitting the PDF into multiple PDFs, one for each page and then measure their respective sizes?
– Uwe Keim
Nov 23 at 8:25
@uweKeim, I don't want to split PDF file page by page. Because think about what would be useful for me if I splited a storybook page by page. It didn't sound professionally to reassemble the page after splitting the pages page by page and removing the blank pages.
– Colin Henricks
Nov 23 at 14:59
1
1
How about splitting the PDF into multiple PDFs, one for each page and then measure their respective sizes?
– Uwe Keim
Nov 23 at 8:25
How about splitting the PDF into multiple PDFs, one for each page and then measure their respective sizes?
– Uwe Keim
Nov 23 at 8:25
@uweKeim, I don't want to split PDF file page by page. Because think about what would be useful for me if I splited a storybook page by page. It didn't sound professionally to reassemble the page after splitting the pages page by page and removing the blank pages.
– Colin Henricks
Nov 23 at 14:59
@uweKeim, I don't want to split PDF file page by page. Because think about what would be useful for me if I splited a storybook page by page. It didn't sound professionally to reassemble the page after splitting the pages page by page and removing the blank pages.
– Colin Henricks
Nov 23 at 14:59
add a comment |
1 Answer
1
active
oldest
votes
2
I would do this in 2 steps:
- first go over the document using IEventListener to detect which pages are empty
- once you've determined which pages are empty, simply create a new document by copying the non-empty pages from the source document into the new document
step 1:
List<Integer> emptyPages = new ArrayList<>();
PdfDocument pdfDocument = new PdfDocument(new PdfReader(new File(SRC)));
for(int i=1;i<pdfDocument.getNumberOfPages();i++){
IsEmptyEventListener l = new IsEmptyEventListener();
new PdfCanvasProcessor(l).processPageContent(pdfDocument.getPage(i));
if(l.isEmptyPage()){
emptyPages.add(i);
}
}
Then you need the proper implementation of IsEmptyEventListener. Which may be tricky and depend on your specific document(s). This is a demo.
class IsEmptyEventListener implements IEventListener {
private int eventCount = 0;
public void eventOccurred(IEventData data, EventType type){
// perhaps count only text rendering events?
eventCount++;
}
public boolean isEmptyPage(){ return eventCount < 32; }
}
step 2:
Based on this example: https://developers.itextpdf.com/examples/stamping-content-existing-pdfs/clone-reordering-pages
void copyNonBlankPages(List<Integer> blankPages, PdfDocument src, PdfDocument dst){
int N = src.getNumberOfPages();
List<Integer> toCopy = new ArrayList<>();
for(int i=1;i<N;i++){
if(!blankPages.contains(i)){
toCopy.add(i);
}
}
src.copyPagesTo(toCopy, dst);
}
answered Nov 27 at 12:36
Joris Schellekens
6,03611141
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
2
I would do this in 2 steps:
- first go over the document using IEventListener to detect which pages are empty
- once you've determined which pages are empty, simply create a new document by copying the non-empty pages from the source document into the new document
step 1:
List<Integer> emptyPages = new ArrayList<>();
PdfDocument pdfDocument = new PdfDocument(new PdfReader(new File(SRC)));
for(int i=1;i<pdfDocument.getNumberOfPages();i++){
IsEmptyEventListener l = new IsEmptyEventListener();
new PdfCanvasProcessor(l).processPageContent(pdfDocument.getPage(i));
if(l.isEmptyPage()){
emptyPages.add(i);
}
}
Then you need the proper implementation of IsEmptyEventListener. Which may be tricky and depend on your specific document(s). This is a demo.
class IsEmptyEventListener implements IEventListener {
private int eventCount = 0;
public void eventOccurred(IEventData data, EventType type){
// perhaps count only text rendering events?
eventCount++;
}
public boolean isEmptyPage(){ return eventCount < 32; }
}
step 2:
Based on this example: https://developers.itextpdf.com/examples/stamping-content-existing-pdfs/clone-reordering-pages
void copyNonBlankPages(List<Integer> blankPages, PdfDocument src, PdfDocument dst){
int N = src.getNumberOfPages();
List<Integer> toCopy = new ArrayList<>();
for(int i=1;i<N;i++){
if(!blankPages.contains(i)){
toCopy.add(i);
}
}
src.copyPagesTo(toCopy, dst);
}
answered Nov 27 at 12:36
Joris Schellekens
6,03611141
add a comment |
2
I would do this in 2 steps:
- first go over the document using IEventListener to detect which pages are empty
- once you've determined which pages are empty, simply create a new document by copying the non-empty pages from the source document into the new document
step 1:
List<Integer> emptyPages = new ArrayList<>();
PdfDocument pdfDocument = new PdfDocument(new PdfReader(new File(SRC)));
for(int i=1;i<pdfDocument.getNumberOfPages();i++){
IsEmptyEventListener l = new IsEmptyEventListener();
new PdfCanvasProcessor(l).processPageContent(pdfDocument.getPage(i));
if(l.isEmptyPage()){
emptyPages.add(i);
}
}
Then you need the proper implementation of IsEmptyEventListener. Which may be tricky and depend on your specific document(s). This is a demo.
class IsEmptyEventListener implements IEventListener {
private int eventCount = 0;
public void eventOccurred(IEventData data, EventType type){
// perhaps count only text rendering events?
eventCount++;
}
public boolean isEmptyPage(){ return eventCount < 32; }
}
step 2:
Based on this example: https://developers.itextpdf.com/examples/stamping-content-existing-pdfs/clone-reordering-pages
void copyNonBlankPages(List<Integer> blankPages, PdfDocument src, PdfDocument dst){
int N = src.getNumberOfPages();
List<Integer> toCopy = new ArrayList<>();
for(int i=1;i<N;i++){
if(!blankPages.contains(i)){
toCopy.add(i);
}
}
src.copyPagesTo(toCopy, dst);
}
answered Nov 27 at 12:36
Joris Schellekens
6,03611141
add a comment |
2
2
2
I would do this in 2 steps:
- first go over the document using IEventListener to detect which pages are empty
- once you've determined which pages are empty, simply create a new document by copying the non-empty pages from the source document into the new document
step 1:
List<Integer> emptyPages = new ArrayList<>();
PdfDocument pdfDocument = new PdfDocument(new PdfReader(new File(SRC)));
for(int i=1;i<pdfDocument.getNumberOfPages();i++){
IsEmptyEventListener l = new IsEmptyEventListener();
new PdfCanvasProcessor(l).processPageContent(pdfDocument.getPage(i));
if(l.isEmptyPage()){
emptyPages.add(i);
}
}
Then you need the proper implementation of IsEmptyEventListener. Which may be tricky and depend on your specific document(s). This is a demo.
class IsEmptyEventListener implements IEventListener {
private int eventCount = 0;
public void eventOccurred(IEventData data, EventType type){
// perhaps count only text rendering events?
eventCount++;
}
public boolean isEmptyPage(){ return eventCount < 32; }
}
step 2:
Based on this example: https://developers.itextpdf.com/examples/stamping-content-existing-pdfs/clone-reordering-pages
void copyNonBlankPages(List<Integer> blankPages, PdfDocument src, PdfDocument dst){
int N = src.getNumberOfPages();
List<Integer> toCopy = new ArrayList<>();
for(int i=1;i<N;i++){
if(!blankPages.contains(i)){
toCopy.add(i);
}
}
src.copyPagesTo(toCopy, dst);
}
answered Nov 27 at 12:36
Joris Schellekens
6,03611141
I would do this in 2 steps:
- first go over the document using IEventListener to detect which pages are empty
- once you've determined which pages are empty, simply create a new document by copying the non-empty pages from the source document into the new document
step 1:
List<Integer> emptyPages = new ArrayList<>();
PdfDocument pdfDocument = new PdfDocument(new PdfReader(new File(SRC)));
for(int i=1;i<pdfDocument.getNumberOfPages();i++){
IsEmptyEventListener l = new IsEmptyEventListener();
new PdfCanvasProcessor(l).processPageContent(pdfDocument.getPage(i));
if(l.isEmptyPage()){
emptyPages.add(i);
}
}
Then you need the proper implementation of IsEmptyEventListener. Which may be tricky and depend on your specific document(s). This is a demo.
class IsEmptyEventListener implements IEventListener {
private int eventCount = 0;
public void eventOccurred(IEventData data, EventType type){
// perhaps count only text rendering events?
eventCount++;
}
public boolean isEmptyPage(){ return eventCount < 32; }
}
step 2:
Based on this example: https://developers.itextpdf.com/examples/stamping-content-existing-pdfs/clone-reordering-pages
void copyNonBlankPages(List<Integer> blankPages, PdfDocument src, PdfDocument dst){
int N = src.getNumberOfPages();
List<Integer> toCopy = new ArrayList<>();
for(int i=1;i<N;i++){
if(!blankPages.contains(i)){
toCopy.add(i);
}
}
src.copyPagesTo(toCopy, dst);
}
answered Nov 27 at 12:36
Joris Schellekens
6,03611141
answered Nov 27 at 12:36
Joris Schellekens
6,03611141
answered Nov 27 at 12:36
Joris Schellekens
6,03611141
answered Nov 27 at 12:36
Joris Schellekens
6,03611141
6,03611141
add a comment |
add a comment |
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1
How about splitting the PDF into multiple PDFs, one for each page and then measure their respective sizes?
– Uwe Keim
Nov 23 at 8:25
@uweKeim, I don't want to split PDF file page by page. Because think about what would be useful for me if I splited a storybook page by page. It didn't sound professionally to reassemble the page after splitting the pages page by page and removing the blank pages.
– Colin Henricks
Nov 23 at 14:59