Initial import

git-svn-id: svn://cook.msm.cam.ac.uk:745/diff-tomo/dtr@1 bf6ca9ba-c028-0410-8290-897cf20841d1

1 files changed, 146 insertions, 0 deletions

diff --git a/src/readpng.c b/src/readpng.c
new file mode 100644
index 0000000..bb5a60b
--- /dev/null
+++ b/src/readpng.c
@@ -0,0 +1,146 @@
+/*
+ * readpng.c
+ *
+ * Read images
+ *
+ * (c) 2007 Thomas White <taw27@cam.ac.uk>
+ *  dtr - Diffraction Tomography Reconstruction
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <png.h>
+#include <math.h>
+
+#include "control.h"
+#include "reflections.h"
+#include "itrans.h"
+
+int readpng_read(const char *filename, double tilt, ControlContext *ctx) {
+
+	FILE *fh;
+	png_bytep header;
+	png_structp png_ptr;
+	png_infop info_ptr;
+	png_infop end_info;
+	unsigned int width;
+	unsigned int height;
+	unsigned int bit_depth;
+	unsigned int channels;
+	png_bytep *row_pointers;
+	unsigned int x;
+	unsigned int y;
+	unsigned int xorig;
+	unsigned int yorig;
+	int16_t *image;
+	
+	/* Open file */
+	fh = fopen(filename, "rb");
+	if ( !fh ) {
+		printf("RI: Couldn't open file '%s'\n", filename);
+		return -1;
+	}
+
+	/* Check it's actually a PNG file */
+	header = malloc(8);
+	fread(header, 1, 8, fh);
+	if ( png_sig_cmp(header, 0, 8)) {
+		printf("RI: Not a PNG file.\n");
+		free(header);
+		fclose(fh);
+		return -1;
+	}
+	free(header);
+	
+	png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+	if ( !png_ptr ) {
+		printf("RI: Couldn't create PNG read structure.\n");
+		fclose(fh);
+		return -1;
+	}
+
+	info_ptr = png_create_info_struct(png_ptr);
+	if ( !info_ptr ) {
+		png_destroy_read_struct(&png_ptr, (png_infopp)NULL, (png_infopp)NULL);
+		printf("RI: Couldn't create PNG info structure.\n");
+		fclose(fh);
+		return -1;
+	}
+
+	end_info = png_create_info_struct(png_ptr);
+	if ( !end_info ) {
+		png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
+		printf("RI: Couldn't create PNG end info structure.\n");
+		fclose(fh);
+		return -1;
+	}
+	
+	if ( setjmp(png_jmpbuf(png_ptr)) ) {
+		png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
+		fclose(fh);
+		printf("RI: PNG read failed.\n");
+		return -1;
+	}
+
+	png_init_io(png_ptr, fh);
+	png_set_sig_bytes(png_ptr, 8);
+	
+	/* Read! */
+	png_read_png(png_ptr, info_ptr, PNG_TRANSFORM_STRIP_ALPHA, NULL);
+
+	width = png_get_image_width(png_ptr, info_ptr);
+	height = png_get_image_height(png_ptr, info_ptr);
+	bit_depth = png_get_bit_depth(png_ptr, info_ptr);
+	channels = png_get_channels(png_ptr, info_ptr);
+//	printf("RI: width=%i, height=%i, depth=%i, channels=%i\n", width, height, bit_depth, channels);
+	if ( (bit_depth != 16) && (bit_depth != 8) ) {
+		printf("RI: Whoops! Can't handle images with other than 8 or 16 bpp yet...\n");
+		png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
+		fclose(fh);
+		return -1;
+	}
+	
+	/* Get image data */
+	row_pointers = png_get_rows(png_ptr, info_ptr);
+	
+	xorig = 320;
+	yorig = 320;	/* For now */
+	image = malloc(height * width * sizeof(int16_t));
+	ctx->width = width; ctx->height = height;
+	ctx->fmode = FORMULATION_CLEN;
+	
+	for ( y=0; y<height; y++ ) {
+		for ( x=0; x<width; x++ ) {
+		
+			int val = 0;
+
+			if ( (x-xorig)*(x-xorig) + (y-yorig)*(y-yorig) < ctx->max_d*ctx->max_d ) {
+			
+				if ( bit_depth == 16 ) {
+					val = row_pointers[y][channels*x] << 8;
+					val += row_pointers[y][(channels*x)+1];
+				}
+				if ( bit_depth == 8 ) {
+					val = row_pointers[y][channels*x];
+				}
+				
+				image[x + width*y] = val;
+					
+			}
+		}
+	}
+	
+	png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
+	fclose(fh);
+
+	itrans_process_image(image, ctx, tilt);
+	
+	return 0;
+	
+}