New upstream version 1.0.29upstream/1.0.29

1 files changed, 193 insertions, 0 deletions

diff --git a/backend/escl/escl_png.c b/backend/escl/escl_png.c
new file mode 100644
index 0000000..18f6f35
--- /dev/null
+++ b/backend/escl/escl_png.c
@@ -0,0 +1,193 @@
+/* sane - Scanner Access Now Easy.
+
+   Copyright (C) 2019 Touboul Nathane
+   Copyright (C) 2019 Thierry HUCHARD <thierry@ordissimo.com>
+
+   This file is part of the SANE package.
+
+   SANE is free software; you can redistribute it and/or modify it under
+   the terms of the GNU General Public License as published by the Free
+   Software Foundation; either version 3 of the License, or (at your
+   option) any later version.
+
+   SANE is distributed in the hope that it will be useful, but WITHOUT
+   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+   for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with sane; see the file COPYING.  If not, write to the Free
+   Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+   This file implements a SANE backend for eSCL scanners.  */
+
+#define DEBUG_DECLARE_ONLY
+#include "../include/sane/config.h"
+
+#include "escl.h"
+
+#include "../include/sane/sanei.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#if(defined HAVE_LIBPNG)
+#include <png.h>
+#endif
+
+#include <setjmp.h>
+
+
+#if(defined HAVE_LIBPNG)
+
+/**
+ * \fn SANE_Status escl_sane_decompressor(escl_sane_t *handler)
+ * \brief Function that aims to decompress the png image to SANE be able to read the image.
+ *        This function is called in the "sane_read" function.
+ *
+ * \return SANE_STATUS_GOOD (if everything is OK, otherwise, SANE_STATUS_NO_MEM/SANE_STATUS_INVAL)
+ */
+SANE_Status
+get_PNG_data(capabilities_t *scanner, int *w, int *h, int *components)
+{
+	unsigned int  width = 0;           /* largeur */
+	unsigned int  height = 0;          /* hauteur */
+	int           bps = 3;  /* composantes d'un texel */
+	unsigned char *texels = NULL;         /* données de l'image */
+        unsigned int i = 0;
+	png_byte magic[8];
+
+	// read magic number
+	fread (magic, 1, sizeof (magic), scanner->tmp);
+	// check for valid magic number
+	if (!png_check_sig (magic, sizeof (magic)))
+	{
+		DBG( 1, "Escl Png : PNG error is not a valid PNG image!\n");
+                if (scanner->tmp) {
+                   fclose(scanner->tmp);
+                   scanner->tmp = NULL;
+                }
+		return (SANE_STATUS_INVAL);
+	}
+	// create a png read struct
+	png_structp png_ptr = png_create_read_struct
+		(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+	if (!png_ptr)
+	{
+		DBG( 1, "Escl Png : PNG error create a png read struct\n");
+                if (scanner->tmp)
+                if (scanner->tmp) {
+                   fclose(scanner->tmp);
+                   scanner->tmp = NULL;
+                }
+		return (SANE_STATUS_INVAL);
+	}
+	// create a png info struct
+	png_infop info_ptr = png_create_info_struct (png_ptr);
+	if (!info_ptr)
+	{
+		DBG( 1, "Escl Png : PNG error create a png info struct\n");
+		png_destroy_read_struct (&png_ptr, NULL, NULL);
+                if (scanner->tmp) {
+                   fclose(scanner->tmp);
+                   scanner->tmp = NULL;
+                }
+		return (SANE_STATUS_INVAL);
+	}
+	// initialize the setjmp for returning properly after a libpng
+	//   error occured
+	if (setjmp (png_jmpbuf (png_ptr)))
+	{
+		png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
+		if (texels)
+		  free (texels);
+        fprintf(stderr,"PNG read error.\n");
+                if (scanner->tmp) {
+                   fclose(scanner->tmp);
+                   scanner->tmp = NULL;
+                }
+		DBG( 1, "Escl Png : PNG read error.\n");
+		return (SANE_STATUS_INVAL);
+	}
+	// setup libpng for using standard C fread() function
+	//   with our FILE pointer
+	png_init_io (png_ptr, scanner->tmp);
+	// tell libpng that we have already read the magic number
+	png_set_sig_bytes (png_ptr, sizeof (magic));
+
+	// read png info
+	png_read_info (png_ptr, info_ptr);
+
+	int bit_depth, color_type;
+	// get some usefull information from header
+	bit_depth = png_get_bit_depth (png_ptr, info_ptr);
+	color_type = png_get_color_type (png_ptr, info_ptr);
+	// convert index color images to RGB images
+	if (color_type == PNG_COLOR_TYPE_PALETTE)
+		png_set_palette_to_rgb (png_ptr);
+	else if (color_type != PNG_COLOR_TYPE_RGB && color_type != PNG_COLOR_TYPE_RGB_ALPHA)
+	{
+        fprintf(stderr,"PNG format not supported.\n");
+                if (scanner->tmp) {
+                   fclose(scanner->tmp);
+                   scanner->tmp = NULL;
+                }
+		return (SANE_STATUS_INVAL);
+	}
+    if (color_type ==  PNG_COLOR_TYPE_RGB_ALPHA)
+        bps = 4;
+    else
+	    bps = 3;
+	if (png_get_valid (png_ptr, info_ptr, PNG_INFO_tRNS))
+		png_set_tRNS_to_alpha (png_ptr);
+	if (bit_depth == 16)
+		png_set_strip_16 (png_ptr);
+	else if (bit_depth < 8)
+		png_set_packing (png_ptr);
+	// update info structure to apply transformations
+	png_read_update_info (png_ptr, info_ptr);
+	// retrieve updated information
+	png_get_IHDR (png_ptr, info_ptr,
+			(png_uint_32*)(&width),
+			(png_uint_32*)(&height),
+			&bit_depth, &color_type,
+			NULL, NULL, NULL);
+
+    *w = (int)width;
+    *h = (int)height;
+    *components = bps;
+	// we can now allocate memory for storing pixel data
+	texels = (unsigned char *)malloc (sizeof (unsigned char) * width
+			* height * bps);
+	png_bytep *row_pointers;
+	// setup a pointer array.  Each one points at the begening of a row.
+	row_pointers = (png_bytep *)malloc (sizeof (png_bytep) * height);
+	for (i = 0; i < height; ++i)
+	{
+		row_pointers[i] = (png_bytep)(texels +
+				((height - (i + 1)) * width * bps));
+	}
+	// read pixel data using row pointers
+	png_read_image (png_ptr, row_pointers);
+	// we don't need row pointers anymore
+	scanner->img_data = texels;
+    scanner->img_size = (int)(width * height * bps);
+    scanner->img_read = 0;
+	free (row_pointers);
+    fclose(scanner->tmp);
+    scanner->tmp = NULL;
+    return (SANE_STATUS_GOOD);
+}
+#else
+
+SANE_Status
+get_PNG_data(capabilities_t __sane_unused__ *scanner,
+              int __sane_unused__ *w,
+              int __sane_unused__ *h,
+              int __sane_unused__ *bps)
+{
+    return (SANE_STATUS_INVAL);
+}
+
+#endif