Re: Patch to add resolution information to iscan
[OK, this time with the patch!]
On Sat, Jul 26, 2003 at 03:42:59PM -0700, Ross Boylan wrote:
> I have attached a patch so that iscan, scanning software for Epson
> scanners from Epson Kowa, will record the scanning resolution when
> saving .png files. Without this, some programs (e.g., hylafax) have
> to assume a resolution, and can be terribly wrong. (I was inspired to
> do this because only the lower left corner of my 400 dpi scans was
> going out, since they were assumed to be postscript standard 72dpi).
>
> I'm not sure if all versions of libpng support pHYS; if not, it might
> be good to protect the code with some appropriate ifdef's. I had
> libpng10-dev (aka libpng2) as my development library when I compiled
> with gcc 3.3.
>
> Despite the name, I have used and applied the patch to iscan 1.5.2,
> gcc 3.2 version. I originally developed it against 1.5.1.
>
> I (c) in my name and release it under GNU Public License v2 or later;
> I believe this is the same license as the software it is patching,
> which is available at
> http://www.epkowa.co.jp/english/linux_e/lsd_e.html.
>
> Ross Boylan
>
>
> P.S. There are some other changes I'd like to make, like having iscan
> remember whether you selected png or pnm, and having it remember what
> directory you are in. I think that requires learning about gtk
> preferences, though.
>
diff -ru iscan-1.5.1/frontend/pisa_change_unit.cc iscan-1.5.1-old/frontend/pisa_change_unit.cc
--- iscan-1.5.1/frontend/pisa_change_unit.cc 2003-02-05 01:58:04.000000000 -0800
+++ iscan-1.5.1-old/frontend/pisa_change_unit.cc 2003-06-19 22:10:37.000000000 -0700
@@ -54,7 +54,6 @@
return ret;
}
-
/*------------------------------------------------------------*/
double inch2centi ( double inch, long zoom )
{
@@ -66,3 +65,13 @@
}
+/*------------------------------------------------------------*/
+unsigned long centi2pixel ( double centi, long resolution, long zoom )
+{
+ unsigned long ret;
+
+ ret = ( long ) ( ( centi * resolution * zoom + 50 ) / (100* INCH2PIXEL));
+
+ return ret;
+}
+
diff -ru iscan-1.5.1/frontend/pisa_change_unit.h iscan-1.5.1-old/frontend/pisa_change_unit.h
--- iscan-1.5.1/frontend/pisa_change_unit.h 2003-02-05 01:58:04.000000000 -0800
+++ iscan-1.5.1-old/frontend/pisa_change_unit.h 2003-06-19 22:11:06.000000000 -0700
@@ -34,5 +34,6 @@
double inches_reflect_zoom ( double inch, long zoom );
long inch2pixel ( double inch, long resolution, long zoom = 100 );
double inch2centi ( double inch, long zoom = 100 );
+unsigned long centi2pixel ( double centi, long resolution, long zoom = 100);
#endif // ___PISA_CHANGE_UNIT_H
diff -ru iscan-1.5.1/frontend/pisa_save_file.cc iscan-1.5.1-old/frontend/pisa_save_file.cc
--- iscan-1.5.1/frontend/pisa_save_file.cc 2003-03-15 01:11:15.000000000 -0800
+++ iscan-1.5.1-old/frontend/pisa_save_file.cc 2003-06-20 21:12:27.000000000 -0700
@@ -31,6 +31,7 @@
#include "pisa_save_file.h"
+#include "pisa_change_unit.h"
#include "pisa_error.h"
#include <dlfcn.h>
@@ -58,11 +59,12 @@
}
void
-base_save_file::set_img_info( char pixel, int width, int height )
+base_save_file::set_img_info( char pixel, int width, int height, long resolution )
{
m_pixel = static_cast< pisa_pixel_type >( pixel );
m_width = width;
m_height = height;
+ m_resolution = resolution;
}
@@ -150,6 +152,7 @@
plib_png_destroy_write_struct = ( lib_png_destroy_write_struct * ) dlsym ( m_handle_libpng, "png_destroy_write_struct" );
plib_png_init_io = ( lib_png_init_io * ) dlsym ( m_handle_libpng, "png_init_io" );
plib_png_set_IHDR = ( lib_png_set_IHDR * ) dlsym ( m_handle_libpng, "png_set_IHDR" );
+ plib_png_set_pHYs = ( lib_png_set_pHYs * ) dlsym ( m_handle_libpng, "png_set_pHYs" );
plib_png_write_info = ( lib_png_write_info * ) dlsym ( m_handle_libpng, "png_write_info" );
plib_png_write_row = ( lib_png_write_row * ) dlsym ( m_handle_libpng, "png_write_row" );
plib_png_write_end = ( lib_png_write_end * ) dlsym ( m_handle_libpng, "png_write_end" );
@@ -160,6 +163,7 @@
! plib_png_destroy_write_struct ||
! plib_png_init_io ||
! plib_png_set_IHDR ||
+ ! plib_png_set_pHYs ||
! plib_png_write_info ||
! plib_png_write_row ||
! plib_png_write_end )
@@ -287,7 +291,16 @@
PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_BASE,
PNG_FILTER_TYPE_BASE );
-
+
+ // should I care about Zoom?
+ png_uint_32 resolution = centi2pixel( 100.0, m_resolution);
+
+ plib_png_set_pHYs( m_png_ptr,
+ m_info_ptr,
+ resolution,
+ resolution,
+ PNG_RESOLUTION_METER);
+
/*write the info*/
plib_png_write_info(m_png_ptr, m_info_ptr);
}
diff -ru iscan-1.5.1/frontend/pisa_save_file.h iscan-1.5.1-old/frontend/pisa_save_file.h
--- iscan-1.5.1/frontend/pisa_save_file.h 2003-03-15 01:11:15.000000000 -0800
+++ iscan-1.5.1-old/frontend/pisa_save_file.h 2003-06-19 22:41:02.000000000 -0700
@@ -42,7 +42,7 @@
virtual ~base_save_file();
base_save_file( const char *const filename );
- void set_img_info( char pixel, int width, int height );
+ void set_img_info( char pixel, int width, int height, long resolution );
virtual void write_header() = 0;
virtual void write_row( unsigned char *img, int size ) = 0;
@@ -56,6 +56,7 @@
int m_width;
int m_height;
+ long m_resolution;
};
class save_file_pnm : public base_save_file
@@ -114,6 +115,11 @@
int interlace_type,
int compression_type,
int filter_type );
+ typedef void ( lib_png_set_pHYs ) ( png_structp png_ptr,
+ png_infop info_ptr,
+ png_uint_32 x,
+ png_uint_32 y,
+ int unit_type );
typedef void ( lib_png_write_info ) ( png_structp png_ptr,
png_infop info_ptr );
typedef void ( lib_png_write_row ) ( png_structp png_ptr,
@@ -127,6 +133,7 @@
lib_png_destroy_write_struct * plib_png_destroy_write_struct;
lib_png_init_io * plib_png_init_io;
lib_png_set_IHDR * plib_png_set_IHDR;
+ lib_png_set_pHYs * plib_png_set_pHYs;
lib_png_write_info * plib_png_write_info;
lib_png_write_row * plib_png_write_row;
lib_png_write_end * plib_png_write_end;
diff -ru iscan-1.5.1/frontend/pisa_view_manager.cc iscan-1.5.1-old/frontend/pisa_view_manager.cc
--- iscan-1.5.1/frontend/pisa_view_manager.cc 2003-04-15 18:25:30.000000000 -0700
+++ iscan-1.5.1-old/frontend/pisa_view_manager.cc 2003-06-19 22:32:02.000000000 -0700
@@ -1152,7 +1152,9 @@
throw pisa_error( PISA_ERR_FILEOPEN );
}
- save_cls->set_img_info( m_set.imgtype.pixeltype, width, height );
+ // Perhaps get resolution from param? But it has two! Ross Boylan
+ save_cls->set_img_info( m_set.imgtype.pixeltype, width, height,
+ ::g_view_manager->m_set.resolution);
try
{
save_cls->write_header();
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