diff --git a/src/3rdparty/libpng/ANNOUNCE b/src/3rdparty/libpng/ANNOUNCE
index 603b2df48e3..15219dbb4e0 100644
--- a/src/3rdparty/libpng/ANNOUNCE
+++ b/src/3rdparty/libpng/ANNOUNCE
@@ -1,5 +1,5 @@
-libpng 1.6.47 - February 18, 2025
-=================================
+libpng 1.6.48 - April 30, 2025
+==============================
 
 This is a public release of libpng, intended for use in production code.
 
@@ -9,13 +9,13 @@ Files available for download
 
 Source files with LF line endings (for Unix/Linux):
 
- * libpng-1.6.47.tar.xz (LZMA-compressed, recommended)
- * libpng-1.6.47.tar.gz (deflate-compressed)
+ * libpng-1.6.48.tar.xz (LZMA-compressed, recommended)
+ * libpng-1.6.48.tar.gz (deflate-compressed)
 
 Source files with CRLF line endings (for Windows):
 
- * lpng1647.7z (LZMA-compressed, recommended)
- * lpng1647.zip (deflate-compressed)
+ * lpng1648.7z (LZMA-compressed, recommended)
+ * lpng1648.zip (deflate-compressed)
 
 Other information:
 
@@ -25,19 +25,17 @@ Other information:
  * TRADEMARK.md
 
 
-Changes from version 1.6.46 to version 1.6.47
+Changes from version 1.6.47 to version 1.6.48
 ---------------------------------------------
 
- * Modified the behaviour of colorspace chunks in order to adhere
-   to the new precedence rules formulated in the latest draft of
-   the PNG Specification.
-   (Contributed by John Bowler)
- * Fixed a latent bug in `png_write_iCCP`.
-   This would have been a read-beyond-end-of-malloc vulnerability,
-   introduced early in the libpng-1.6.0 development, yet (fortunately!)
-   it was inaccessible before the above-mentioned modification of the
-   colorspace precedence rules, due to pre-existing colorspace checks.
-   (Reported by Bob Friesenhahn; fixed by John Bowler)
+ * Fixed the floating-point version of the mDCv setter `png_set_mDCv`.
+   (Reported by Mohit Bakshi; fixed by John Bowler)
+ * Added #error directives to discourage the inclusion of private
+   libpng implementation header files in PNG-supporting applications.
+ * Added the CMake build option `PNG_LIBCONF_HEADER`, to be used as an
+   alternative to `DFA_XTRA`.
+ * Removed the Travis CI configuration files, with heartfelt thanks for
+   their generous support of our project over the past five years!
 
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net.
diff --git a/src/3rdparty/libpng/CHANGES b/src/3rdparty/libpng/CHANGES
index 834b5e19277..557ff1b8c97 100644
--- a/src/3rdparty/libpng/CHANGES
+++ b/src/3rdparty/libpng/CHANGES
@@ -6251,6 +6251,16 @@ Version 1.6.47 [February 18, 2025]
     colorspace precedence rules, due to pre-existing colorspace checks.
     (Reported by Bob Friesenhahn; fixed by John Bowler)
 
+Version 1.6.48 [April 30, 2025]
+  Fixed the floating-point version of the mDCv setter `png_set_mDCv`.
+    (Reported by Mohit Bakshi; fixed by John Bowler)
+  Added #error directives to discourage the inclusion of private
+    libpng implementation header files in PNG-supporting applications.
+  Added the CMake build option `PNG_LIBCONF_HEADER`, to be used as an
+    alternative to `DFA_XTRA`.
+  Removed the Travis CI configuration files, with heartfelt thanks for
+    their generous support of our project over the past five years!
+
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net.
 Subscription is required; visit
 https://lists.sourceforge.net/lists/listinfo/png-mng-implement
diff --git a/src/3rdparty/libpng/README b/src/3rdparty/libpng/README
index 57952fb215a..cbde7246ca2 100644
--- a/src/3rdparty/libpng/README
+++ b/src/3rdparty/libpng/README
@@ -1,4 +1,4 @@
-README for libpng version 1.6.47
+README for libpng version 1.6.48
 ================================
 
 See the note about version numbers near the top of `png.h`.
diff --git a/src/3rdparty/libpng/libpng-manual.txt b/src/3rdparty/libpng/libpng-manual.txt
index 862fe2c5d0f..940c2e2b513 100644
--- a/src/3rdparty/libpng/libpng-manual.txt
+++ b/src/3rdparty/libpng/libpng-manual.txt
@@ -9,7 +9,7 @@ libpng-manual.txt - A description on how to use and modify libpng
 
  Based on:
 
- libpng version 1.6.36, December 2018, through 1.6.47 - February 2025
+ libpng version 1.6.36, December 2018, through 1.6.48 - April 2025
  Updated and distributed by Cosmin Truta
  Copyright (c) 2018-2025 Cosmin Truta
 
@@ -4089,7 +4089,7 @@ READ APIs
      is filled in from the PNG header in the file.
 
    int png_image_begin_read_from_stdio (png_imagep image,
-     FILE* file)
+     FILE *file)
 
       The PNG header is read from the stdio FILE object.
 
@@ -4164,7 +4164,7 @@ be written:
       int convert_to_8_bit, const void *buffer,
       png_int_32 row_stride, const void *colormap)
 
-      Write the image to the given (FILE*).
+      Write the image to the given FILE object.
 
 With all write APIs if image is in one of the linear formats with
 (png_uint_16) data then setting convert_to_8_bit will cause the output to be
diff --git a/src/3rdparty/libpng/png.c b/src/3rdparty/libpng/png.c
index 6d533ec40b4..a9179ffbbdd 100644
--- a/src/3rdparty/libpng/png.c
+++ b/src/3rdparty/libpng/png.c
@@ -13,7 +13,7 @@
 #include "pngpriv.h"
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef png_libpng_version_1_6_47 Your_png_h_is_not_version_1_6_47;
+typedef png_libpng_version_1_6_48 Your_png_h_is_not_version_1_6_48;
 
 /* Sanity check the chunks definitions - PNG_KNOWN_CHUNKS from pngpriv.h and the
  * corresponding macro definitions.  This causes a compile time failure if
@@ -700,7 +700,7 @@ png_get_io_ptr(png_const_structrp png_ptr)
  * function of your own because "FILE *" isn't necessarily available.
  */
 void PNGAPI
-png_init_io(png_structrp png_ptr, png_FILE_p fp)
+png_init_io(png_structrp png_ptr, FILE *fp)
 {
    png_debug(1, "in png_init_io");
 
@@ -815,7 +815,7 @@ png_get_copyright(png_const_structrp png_ptr)
    return PNG_STRING_COPYRIGHT
 #else
    return PNG_STRING_NEWLINE \
-      "libpng version 1.6.47" PNG_STRING_NEWLINE \
+      "libpng version 1.6.48" PNG_STRING_NEWLINE \
       "Copyright (c) 2018-2025 Cosmin Truta" PNG_STRING_NEWLINE \
       "Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson" \
       PNG_STRING_NEWLINE \
@@ -1491,7 +1491,7 @@ png_XYZ_from_xy(png_XYZ *XYZ, const png_xy *xy)
 }
 #endif /* COLORSPACE */
 
-#ifdef PNG_iCCP_SUPPORTED
+#ifdef PNG_READ_iCCP_SUPPORTED
 /* Error message generation */
 static char
 png_icc_tag_char(png_uint_32 byte)
@@ -1567,9 +1567,7 @@ png_icc_profile_error(png_const_structrp png_ptr, png_const_charp name,
 
    return 0;
 }
-#endif /* iCCP */
 
-#ifdef PNG_READ_iCCP_SUPPORTED
 /* Encoded value of D50 as an ICC XYZNumber.  From the ICC 2010 spec the value
  * is XYZ(0.9642,1.0,0.8249), which scales to:
  *
@@ -3969,7 +3967,7 @@ png_image_free_function(png_voidp argument)
 #  ifdef PNG_STDIO_SUPPORTED
       if (cp->owned_file != 0)
       {
-         FILE *fp = png_voidcast(FILE*, cp->png_ptr->io_ptr);
+         FILE *fp = png_voidcast(FILE *, cp->png_ptr->io_ptr);
          cp->owned_file = 0;
 
          /* Ignore errors here. */
diff --git a/src/3rdparty/libpng/png.h b/src/3rdparty/libpng/png.h
index 9b069e4ee89..665511c5547 100644
--- a/src/3rdparty/libpng/png.h
+++ b/src/3rdparty/libpng/png.h
@@ -1,6 +1,6 @@
 /* png.h - header file for PNG reference library
  *
- * libpng version 1.6.47
+ * libpng version 1.6.48
  *
  * Copyright (c) 2018-2025 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
@@ -14,7 +14,7 @@
  *   libpng versions 0.89, June 1996, through 0.96, May 1997: Andreas Dilger
  *   libpng versions 0.97, January 1998, through 1.6.35, July 2018:
  *     Glenn Randers-Pehrson
- *   libpng versions 1.6.36, December 2018, through 1.6.47, February 2025:
+ *   libpng versions 1.6.36, December 2018, through 1.6.48, April 2025:
  *     Cosmin Truta
  *   See also "Contributing Authors", below.
  */
@@ -238,7 +238,7 @@
  *    ...
  *    1.5.30                  15    10530  15.so.15.30[.0]
  *    ...
- *    1.6.47                  16    10647  16.so.16.47[.0]
+ *    1.6.48                  16    10648  16.so.16.48[.0]
  *
  *    Henceforth the source version will match the shared-library major and
  *    minor numbers; the shared-library major version number will be used for
@@ -274,7 +274,7 @@
  */
 
 /* Version information for png.h - this should match the version in png.c */
-#define PNG_LIBPNG_VER_STRING "1.6.47"
+#define PNG_LIBPNG_VER_STRING "1.6.48"
 #define PNG_HEADER_VERSION_STRING " libpng version " PNG_LIBPNG_VER_STRING "\n"
 
 /* The versions of shared library builds should stay in sync, going forward */
@@ -285,7 +285,7 @@
 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
 #define PNG_LIBPNG_VER_MAJOR   1
 #define PNG_LIBPNG_VER_MINOR   6
-#define PNG_LIBPNG_VER_RELEASE 47
+#define PNG_LIBPNG_VER_RELEASE 48
 
 /* This should be zero for a public release, or non-zero for a
  * development version.
@@ -316,7 +316,7 @@
  * From version 1.0.1 it is:
  * XXYYZZ, where XX=major, YY=minor, ZZ=release
  */
-#define PNG_LIBPNG_VER 10647 /* 1.6.47 */
+#define PNG_LIBPNG_VER 10648 /* 1.6.48 */
 
 /* Library configuration: these options cannot be changed after
  * the library has been built.
@@ -426,7 +426,7 @@ extern "C" {
 /* This triggers a compiler error in png.c, if png.c and png.h
  * do not agree upon the version number.
  */
-typedef char* png_libpng_version_1_6_47;
+typedef char* png_libpng_version_1_6_48;
 
 /* Basic control structions.  Read libpng-manual.txt or libpng.3 for more info.
  *
@@ -1570,7 +1570,7 @@ PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr,
 
 #ifdef PNG_STDIO_SUPPORTED
 /* Initialize the input/output for the PNG file to the default functions. */
-PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, png_FILE_p fp));
+PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, FILE *fp));
 #endif
 
 /* Replace the (error and abort), and warning functions with user
@@ -3088,7 +3088,7 @@ PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image,
     */
 
 PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image,
-   FILE* file));
+   FILE *file));
    /* The PNG header is read from the stdio FILE object. */
 #endif /* STDIO */
 
@@ -3163,7 +3163,7 @@ PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image,
 PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file,
    int convert_to_8_bit, const void *buffer, png_int_32 row_stride,
    const void *colormap));
-   /* Write the image to the given (FILE*). */
+   /* Write the image to the given FILE object. */
 #endif /* SIMPLIFIED_WRITE_STDIO */
 
 /* With all write APIs if image is in one of the linear formats with 16-bit
diff --git a/src/3rdparty/libpng/pngconf.h b/src/3rdparty/libpng/pngconf.h
index 42fa973c206..e46b0611190 100644
--- a/src/3rdparty/libpng/pngconf.h
+++ b/src/3rdparty/libpng/pngconf.h
@@ -1,6 +1,6 @@
 /* pngconf.h - machine-configurable file for libpng
  *
- * libpng version 1.6.47
+ * libpng version 1.6.48
  *
  * Copyright (c) 2018-2025 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2016,2018 Glenn Randers-Pehrson
@@ -219,25 +219,13 @@
   /* NOTE: PNGCBAPI always defaults to PNGCAPI. */
 
 #  if defined(PNGAPI) && !defined(PNG_USER_PRIVATEBUILD)
-#     error "PNG_USER_PRIVATEBUILD must be defined if PNGAPI is changed"
+#     error PNG_USER_PRIVATEBUILD must be defined if PNGAPI is changed
 #  endif
 
-#  if (defined(_MSC_VER) && _MSC_VER < 800) ||\
-      (defined(__BORLANDC__) && __BORLANDC__ < 0x500)
-   /* older Borland and MSC
-    * compilers used '__export' and required this to be after
-    * the type.
-    */
-#    ifndef PNG_EXPORT_TYPE
-#      define PNG_EXPORT_TYPE(type) type PNG_IMPEXP
-#    endif
-#    define PNG_DLL_EXPORT __export
-#  else /* newer compiler */
-#    define PNG_DLL_EXPORT __declspec(dllexport)
-#    ifndef PNG_DLL_IMPORT
-#      define PNG_DLL_IMPORT __declspec(dllimport)
-#    endif
-#  endif /* compiler */
+#  define PNG_DLL_EXPORT __declspec(dllexport)
+#  ifndef PNG_DLL_IMPORT
+#    define PNG_DLL_IMPORT __declspec(dllimport)
+#  endif
 
 #else /* !Windows */
 #  if (defined(__IBMC__) || defined(__IBMCPP__)) && defined(__OS2__)
@@ -479,7 +467,7 @@
 #if CHAR_BIT == 8 && UCHAR_MAX == 255
    typedef unsigned char png_byte;
 #else
-#  error "libpng requires 8-bit bytes"
+#  error libpng requires 8-bit bytes
 #endif
 
 #if INT_MIN == -32768 && INT_MAX == 32767
@@ -487,7 +475,7 @@
 #elif SHRT_MIN == -32768 && SHRT_MAX == 32767
    typedef short png_int_16;
 #else
-#  error "libpng requires a signed 16-bit type"
+#  error libpng requires a signed 16-bit integer type
 #endif
 
 #if UINT_MAX == 65535
@@ -495,7 +483,7 @@
 #elif USHRT_MAX == 65535
    typedef unsigned short png_uint_16;
 #else
-#  error "libpng requires an unsigned 16-bit type"
+#  error libpng requires an unsigned 16-bit integer type
 #endif
 
 #if INT_MIN < -2147483646 && INT_MAX > 2147483646
@@ -503,7 +491,7 @@
 #elif LONG_MIN < -2147483646 && LONG_MAX > 2147483646
    typedef long int png_int_32;
 #else
-#  error "libpng requires a signed 32-bit (or more) type"
+#  error libpng requires a signed 32-bit (or longer) integer type
 #endif
 
 #if UINT_MAX > 4294967294U
@@ -511,7 +499,7 @@
 #elif ULONG_MAX > 4294967294U
    typedef unsigned long int png_uint_32;
 #else
-#  error "libpng requires an unsigned 32-bit (or more) type"
+#  error libpng requires an unsigned 32-bit (or longer) integer type
 #endif
 
 /* Prior to 1.6.0, it was possible to disable the use of size_t and ptrdiff_t.
@@ -592,10 +580,6 @@ typedef const png_fixed_point * png_const_fixed_point_p;
 typedef size_t                * png_size_tp;
 typedef const size_t          * png_const_size_tp;
 
-#ifdef PNG_STDIO_SUPPORTED
-typedef FILE            * png_FILE_p;
-#endif
-
 #ifdef PNG_FLOATING_POINT_SUPPORTED
 typedef double       * png_doublep;
 typedef const double * png_const_doublep;
@@ -617,6 +601,15 @@ typedef double          * * png_doublepp;
 /* Pointers to pointers to pointers; i.e., pointer to array */
 typedef char            * * * png_charppp;
 
+#ifdef PNG_STDIO_SUPPORTED
+/* With PNG_STDIO_SUPPORTED it was possible to use I/O streams that were
+ * not necessarily stdio FILE streams, to allow building Windows applications
+ * before Win32 and Windows CE applications before WinCE 3.0, but that kind
+ * of support has long been discontinued.
+ */
+typedef FILE            * png_FILE_p; /* [Deprecated] */
+#endif
+
 #endif /* PNG_BUILDING_SYMBOL_TABLE */
 
 #endif /* PNGCONF_H */
diff --git a/src/3rdparty/libpng/pngdebug.h b/src/3rdparty/libpng/pngdebug.h
index ab9ea632d91..af1ae9e8212 100644
--- a/src/3rdparty/libpng/pngdebug.h
+++ b/src/3rdparty/libpng/pngdebug.h
@@ -1,6 +1,6 @@
-/* pngdebug.h - Debugging macros for libpng, also used in pngtest.c
+/* pngdebug.h - internal debugging macros for libpng
  *
- * Copyright (c) 2018 Cosmin Truta
+ * Copyright (c) 2018-2025 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2013 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
@@ -10,6 +10,10 @@
  * and license in png.h
  */
 
+#ifndef PNGPRIV_H
+#  error This file must not be included by applications; please include <png.h>
+#endif
+
 /* Define PNG_DEBUG at compile time for debugging information.  Higher
  * numbers for PNG_DEBUG mean more debugging information.  This has
  * only been added since version 0.95 so it is not implemented throughout
diff --git a/src/3rdparty/libpng/pngerror.c b/src/3rdparty/libpng/pngerror.c
index 275b188d040..01a7ef5347e 100644
--- a/src/3rdparty/libpng/pngerror.c
+++ b/src/3rdparty/libpng/pngerror.c
@@ -1,6 +1,6 @@
 /* pngerror.c - stub functions for i/o and memory allocation
  *
- * Copyright (c) 2018-2024 Cosmin Truta
+ * Copyright (c) 2018-2025 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
diff --git a/src/3rdparty/libpng/pngget.c b/src/3rdparty/libpng/pngget.c
index 3623c5c7c32..1ebb1144ffc 100644
--- a/src/3rdparty/libpng/pngget.c
+++ b/src/3rdparty/libpng/pngget.c
@@ -1,6 +1,6 @@
 /* pngget.c - retrieval of values from info struct
  *
- * Copyright (c) 2018-2024 Cosmin Truta
+ * Copyright (c) 2018-2025 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
diff --git a/src/3rdparty/libpng/pnginfo.h b/src/3rdparty/libpng/pnginfo.h
index c2a907bc587..584a42f9568 100644
--- a/src/3rdparty/libpng/pnginfo.h
+++ b/src/3rdparty/libpng/pnginfo.h
@@ -1,6 +1,6 @@
-/* pnginfo.h - header file for PNG reference library
+/* pnginfo.h - internal structures for libpng
  *
- * Copyright (c) 2018 Cosmin Truta
+ * Copyright (c) 2018-2025 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2013,2018 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
@@ -10,43 +10,20 @@
  * and license in png.h
  */
 
- /* png_info is a structure that holds the information in a PNG file so
- * that the application can find out the characteristics of the image.
- * If you are reading the file, this structure will tell you what is
- * in the PNG file.  If you are writing the file, fill in the information
- * you want to put into the PNG file, using png_set_*() functions, then
- * call png_write_info().
+#ifndef PNGPRIV_H
+#  error This file must not be included by applications; please include <png.h>
+#endif
+
+/* INTERNAL, PRIVATE definition of a PNG.
  *
- * The names chosen should be very close to the PNG specification, so
- * consult that document for information about the meaning of each field.
+ * png_info is a modifiable description of a PNG datastream.  The fields inside
+ * this structure are accessed through png_get_<CHUNK>() functions and modified
+ * using png_set_<CHUNK>() functions.
  *
- * With libpng < 0.95, it was only possible to directly set and read the
- * the values in the png_info_struct, which meant that the contents and
- * order of the values had to remain fixed.  With libpng 0.95 and later,
- * however, there are now functions that abstract the contents of
- * png_info_struct from the application, so this makes it easier to use
- * libpng with dynamic libraries, and even makes it possible to use
- * libraries that don't have all of the libpng ancillary chunk-handing
- * functionality.  In libpng-1.5.0 this was moved into a separate private
- * file that is not visible to applications.
- *
- * The following members may have allocated storage attached that should be
- * cleaned up before the structure is discarded: palette, trans, text,
- * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile,
- * splt_palettes, scal_unit, row_pointers, and unknowns.   By default, these
- * are automatically freed when the info structure is deallocated, if they were
- * allocated internally by libpng.  This behavior can be changed by means
- * of the png_data_freer() function.
- *
- * More allocation details: all the chunk-reading functions that
- * change these members go through the corresponding png_set_*
- * functions.  A function to clear these members is available: see
- * png_free_data().  The png_set_* functions do not depend on being
- * able to point info structure members to any of the storage they are
- * passed (they make their own copies), EXCEPT that the png_set_text
- * functions use the same storage passed to them in the text_ptr or
- * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns
- * functions do not make their own copies.
+ * Some functions in libpng do directly access members of png_info.  However,
+ * this should be avoided.  png_struct objects contain members which hold
+ * caches, sometimes optimised, of the values from png_info objects, and
+ * png_info is not passed to the functions which read and write image data.
  */
 #ifndef PNGINFO_H
 #define PNGINFO_H
diff --git a/src/3rdparty/libpng/pnglibconf.h b/src/3rdparty/libpng/pnglibconf.h
index 748220bfc1c..c7634440de8 100644
--- a/src/3rdparty/libpng/pnglibconf.h
+++ b/src/3rdparty/libpng/pnglibconf.h
@@ -1,6 +1,6 @@
 /* pnglibconf.h - library build configuration */
 
-/* libpng version 1.6.47 */
+/* libpng version 1.6.48 */
 
 /* Copyright (c) 2018-2025 Cosmin Truta */
 /* Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson */
diff --git a/src/3rdparty/libpng/pngmem.c b/src/3rdparty/libpng/pngmem.c
index 90c13b10684..71e61c99f79 100644
--- a/src/3rdparty/libpng/pngmem.c
+++ b/src/3rdparty/libpng/pngmem.c
@@ -1,6 +1,6 @@
 /* pngmem.c - stub functions for memory allocation
  *
- * Copyright (c) 2018 Cosmin Truta
+ * Copyright (c) 2018-2025 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2014,2016 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
diff --git a/src/3rdparty/libpng/pngpread.c b/src/3rdparty/libpng/pngpread.c
index 60d810693b3..0a3e822cf47 100644
--- a/src/3rdparty/libpng/pngpread.c
+++ b/src/3rdparty/libpng/pngpread.c
@@ -1,6 +1,6 @@
 /* pngpread.c - read a png file in push mode
  *
- * Copyright (c) 2018-2024 Cosmin Truta
+ * Copyright (c) 2018-2025 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
diff --git a/src/3rdparty/libpng/pngpriv.h b/src/3rdparty/libpng/pngpriv.h
index d514dff5c16..a6f8d67d384 100644
--- a/src/3rdparty/libpng/pngpriv.h
+++ b/src/3rdparty/libpng/pngpriv.h
@@ -1,6 +1,6 @@
 /* pngpriv.h - private declarations for use inside libpng
  *
- * Copyright (c) 2018-2024 Cosmin Truta
+ * Copyright (c) 2018-2025 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
@@ -19,8 +19,20 @@
  * they should be well aware of the issues that may arise from doing so.
  */
 
+
+/* pngpriv.h must be included first in each translation unit inside libpng.
+ * On the other hand, it must not be included at all, directly or indirectly,
+ * by any application code that uses the libpng API.
+ */
 #ifndef PNGPRIV_H
-#define PNGPRIV_H
+#  define PNGPRIV_H
+#else
+#  error Duplicate inclusion of pngpriv.h; please check the libpng source files
+#endif
+
+#if defined(PNG_H) || defined(PNGCONF_H) || defined(PNGLCONF_H)
+#  error This file must not be included by applications; please include <png.h>
+#endif
 
 /* Feature Test Macros.  The following are defined here to ensure that correctly
  * implemented libraries reveal the APIs libpng needs to build and hide those
@@ -57,7 +69,6 @@
  */
 #if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H)
 #  include <config.h>
-
    /* Pick up the definition of 'restrict' from config.h if it was read: */
 #  define PNG_RESTRICT restrict
 #endif
@@ -67,9 +78,7 @@
  * are not internal definitions may be required.  This is handled below just
  * before png.h is included, but load the configuration now if it is available.
  */
-#ifndef PNGLCONF_H
-#  include "pnglibconf.h"
-#endif
+#include "pnglibconf.h"
 
 /* Local renames may change non-exported API functions from png.h */
 #if defined(PNG_PREFIX) && !defined(PNGPREFIX_H)
@@ -991,17 +1000,15 @@
  * must match that used in the build, or we must be using pnglibconf.h.prebuilt:
  */
 #if PNG_ZLIB_VERNUM != 0 && PNG_ZLIB_VERNUM != ZLIB_VERNUM
-#  error ZLIB_VERNUM != PNG_ZLIB_VERNUM \
-      "-I (include path) error: see the notes in pngpriv.h"
-   /* This means that when pnglibconf.h was built the copy of zlib.h that it
-    * used is not the same as the one being used here.  Because the build of
-    * libpng makes decisions to use inflateInit2 and inflateReset2 based on the
-    * zlib version number and because this affects handling of certain broken
-    * PNG files the -I directives must match.
+#  error The include path of <zlib.h> is incorrect
+   /* When pnglibconf.h was built, the copy of zlib.h that it used was not the
+    * same as the one being used here.  Considering how libpng makes decisions
+    * to use the zlib API based on the zlib version number, the -I options must
+    * match.
     *
-    * The most likely explanation is that you passed a -I in CFLAGS. This will
-    * not work; all the preprocessor directives and in particular all the -I
-    * directives must be in CPPFLAGS.
+    * A possible cause of this mismatch is that you passed an -I option in
+    * CFLAGS, which is unlikely to work.  All the preprocessor options, and all
+    * the -I options in particular, should be in CPPFLAGS.
     */
 #endif
 
@@ -2162,4 +2169,3 @@ PNG_INTERNAL_FUNCTION(int,
 #endif
 
 #endif /* PNG_VERSION_INFO_ONLY */
-#endif /* PNGPRIV_H */
diff --git a/src/3rdparty/libpng/pngread.c b/src/3rdparty/libpng/pngread.c
index 0fd364827eb..4f55f6408b8 100644
--- a/src/3rdparty/libpng/pngread.c
+++ b/src/3rdparty/libpng/pngread.c
@@ -1328,7 +1328,7 @@ png_image_read_header(png_voidp argument)
 
 #ifdef PNG_STDIO_SUPPORTED
 int PNGAPI
-png_image_begin_read_from_stdio(png_imagep image, FILE* file)
+png_image_begin_read_from_stdio(png_imagep image, FILE *file)
 {
    if (image != NULL && image->version == PNG_IMAGE_VERSION)
    {
diff --git a/src/3rdparty/libpng/pngrio.c b/src/3rdparty/libpng/pngrio.c
index 3b137f275f8..b4a216161be 100644
--- a/src/3rdparty/libpng/pngrio.c
+++ b/src/3rdparty/libpng/pngrio.c
@@ -1,6 +1,6 @@
 /* pngrio.c - functions for data input
  *
- * Copyright (c) 2018 Cosmin Truta
+ * Copyright (c) 2018-2025 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2016,2018 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
@@ -56,7 +56,7 @@ png_default_read_data(png_structp png_ptr, png_bytep data, size_t length)
    /* fread() returns 0 on error, so it is OK to store this in a size_t
     * instead of an int, which is what fread() actually returns.
     */
-   check = fread(data, 1, length, png_voidcast(png_FILE_p, png_ptr->io_ptr));
+   check = fread(data, 1, length, png_voidcast(FILE *, png_ptr->io_ptr));
 
    if (check != length)
       png_error(png_ptr, "Read Error");
diff --git a/src/3rdparty/libpng/pngrtran.c b/src/3rdparty/libpng/pngrtran.c
index a6ce30a5231..0fea13a418d 100644
--- a/src/3rdparty/libpng/pngrtran.c
+++ b/src/3rdparty/libpng/pngrtran.c
@@ -1,6 +1,6 @@
 /* pngrtran.c - transforms the data in a row for PNG readers
  *
- * Copyright (c) 2018-2024 Cosmin Truta
+ * Copyright (c) 2018-2025 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
diff --git a/src/3rdparty/libpng/pngrutil.c b/src/3rdparty/libpng/pngrutil.c
index d0f3ed35d2d..7d9a00186dc 100644
--- a/src/3rdparty/libpng/pngrutil.c
+++ b/src/3rdparty/libpng/pngrutil.c
@@ -1,6 +1,6 @@
 /* pngrutil.c - utilities to read a PNG file
  *
- * Copyright (c) 2018-2024 Cosmin Truta
+ * Copyright (c) 2018-2025 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
diff --git a/src/3rdparty/libpng/pngset.c b/src/3rdparty/libpng/pngset.c
index d7f3393c437..3e63c2724ec 100644
--- a/src/3rdparty/libpng/pngset.c
+++ b/src/3rdparty/libpng/pngset.c
@@ -300,17 +300,14 @@ png_set_mDCV(png_const_structrp png_ptr, png_inforp info_ptr,
     double maxDL, double minDL)
 {
    png_set_mDCV_fixed(png_ptr, info_ptr,
-      /* The ITU approach is to scale by 50,000, not 100,000 so just divide
-       * the input values by 2 and use png_fixed:
-       */
-      png_fixed(png_ptr, white_x / 2, "png_set_mDCV(white(x))"),
-      png_fixed(png_ptr, white_y / 2, "png_set_mDCV(white(y))"),
-      png_fixed(png_ptr, red_x / 2, "png_set_mDCV(red(x))"),
-      png_fixed(png_ptr, red_y / 2, "png_set_mDCV(red(y))"),
-      png_fixed(png_ptr, green_x / 2, "png_set_mDCV(green(x))"),
-      png_fixed(png_ptr, green_y / 2, "png_set_mDCV(green(y))"),
-      png_fixed(png_ptr, blue_x / 2, "png_set_mDCV(blue(x))"),
-      png_fixed(png_ptr, blue_y / 2, "png_set_mDCV(blue(y))"),
+      png_fixed(png_ptr, white_x, "png_set_mDCV(white(x))"),
+      png_fixed(png_ptr, white_y, "png_set_mDCV(white(y))"),
+      png_fixed(png_ptr, red_x, "png_set_mDCV(red(x))"),
+      png_fixed(png_ptr, red_y, "png_set_mDCV(red(y))"),
+      png_fixed(png_ptr, green_x, "png_set_mDCV(green(x))"),
+      png_fixed(png_ptr, green_y, "png_set_mDCV(green(y))"),
+      png_fixed(png_ptr, blue_x, "png_set_mDCV(blue(x))"),
+      png_fixed(png_ptr, blue_y, "png_set_mDCV(blue(y))"),
       png_fixed_ITU(png_ptr, maxDL, "png_set_mDCV(maxDL)"),
       png_fixed_ITU(png_ptr, minDL, "png_set_mDCV(minDL)"));
 }
diff --git a/src/3rdparty/libpng/pngstruct.h b/src/3rdparty/libpng/pngstruct.h
index 324424495e4..b17a54fe8f9 100644
--- a/src/3rdparty/libpng/pngstruct.h
+++ b/src/3rdparty/libpng/pngstruct.h
@@ -1,6 +1,6 @@
-/* pngstruct.h - header file for PNG reference library
+/* pngstruct.h - internal structures for libpng
  *
- * Copyright (c) 2018-2022 Cosmin Truta
+ * Copyright (c) 2018-2025 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
@@ -10,11 +10,9 @@
  * and license in png.h
  */
 
-/* The structure that holds the information to read and write PNG files.
- * The only people who need to care about what is inside of this are the
- * people who will be modifying the library for their own special needs.
- * It should NOT be accessed directly by an application.
- */
+#ifndef PNGPRIV_H
+#  error This file must not be included by applications; please include <png.h>
+#endif
 
 #ifndef PNGSTRUCT_H
 #define PNGSTRUCT_H
diff --git a/src/3rdparty/libpng/pngwio.c b/src/3rdparty/libpng/pngwio.c
index 38c9c006cb1..96a3187ff01 100644
--- a/src/3rdparty/libpng/pngwio.c
+++ b/src/3rdparty/libpng/pngwio.c
@@ -1,6 +1,6 @@
 /* pngwio.c - functions for data output
  *
- * Copyright (c) 2018 Cosmin Truta
+ * Copyright (c) 2018-2025 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2014,2016,2018 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
@@ -54,7 +54,7 @@ png_default_write_data(png_structp png_ptr, png_bytep data, size_t length)
    if (png_ptr == NULL)
       return;
 
-   check = fwrite(data, 1, length, (png_FILE_p)(png_ptr->io_ptr));
+   check = fwrite(data, 1, length, (FILE *)png_ptr->io_ptr);
 
    if (check != length)
       png_error(png_ptr, "Write Error");
@@ -77,12 +77,12 @@ png_flush(png_structrp png_ptr)
 void PNGCBAPI
 png_default_flush(png_structp png_ptr)
 {
-   png_FILE_p io_ptr;
+   FILE *io_ptr;
 
    if (png_ptr == NULL)
       return;
 
-   io_ptr = png_voidcast(png_FILE_p, (png_ptr->io_ptr));
+   io_ptr = png_voidcast(FILE *, png_ptr->io_ptr);
    fflush(io_ptr);
 }
 #  endif
diff --git a/src/3rdparty/libpng/pngwrite.c b/src/3rdparty/libpng/pngwrite.c
index b7aeff4ce4a..35a5d17b601 100644
--- a/src/3rdparty/libpng/pngwrite.c
+++ b/src/3rdparty/libpng/pngwrite.c
@@ -2333,7 +2333,7 @@ int PNGAPI
 png_image_write_to_stdio(png_imagep image, FILE *file, int convert_to_8bit,
     const void *buffer, png_int_32 row_stride, const void *colormap)
 {
-   /* Write the image to the given (FILE*). */
+   /* Write the image to the given FILE object. */
    if (image != NULL && image->version == PNG_IMAGE_VERSION)
    {
       if (file != NULL && buffer != NULL)
diff --git a/src/3rdparty/libpng/pngwutil.c b/src/3rdparty/libpng/pngwutil.c
index be706afe640..863ffe8c2fb 100644
--- a/src/3rdparty/libpng/pngwutil.c
+++ b/src/3rdparty/libpng/pngwutil.c
@@ -1,6 +1,6 @@
 /* pngwutil.c - utilities to write a PNG file
  *
- * Copyright (c) 2018-2024 Cosmin Truta
+ * Copyright (c) 2018-2025 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
diff --git a/src/3rdparty/libpng/qt_attribution.json b/src/3rdparty/libpng/qt_attribution.json
index e36589f50f0..d300d9d9b52 100644
--- a/src/3rdparty/libpng/qt_attribution.json
+++ b/src/3rdparty/libpng/qt_attribution.json
@@ -7,8 +7,8 @@
 
     "Description": "libpng is the official PNG reference library.",
     "Homepage": "http://www.libpng.org/pub/png/libpng.html",
-    "Version": "1.6.47",
-    "DownloadLocation": "https://download.sourceforge.net/libpng/libpng-1.6.47.tar.xz",
+    "Version": "1.6.48",
+    "DownloadLocation": "https://download.sourceforge.net/libpng/libpng-1.6.48.tar.xz",
     "PURL": "pkg:github/pnggroup/libpng@v$<VERSION>",
     "CPE": "cpe:2.3:a:libpng:libpng:$<VERSION>:*:*:*:*:*:*:*",