Image tool and samples

png_to_vmu_lcd/Makefile

@@ -0,0 +1,17 @@
+CC=gcc
+LD=$(CC)
+CFLAGS=-Wall -g `libpng-config --cflags`
+LDFLAGS=`libpng-config --libs`
+
+PROG=png_to_vmu_lcd
+OBJS=main.o
+
+all: $(PROG)
+
+clean:
+	rm $(PROG) $(OBJS)
+
+$(PROG): $(OBJS)
+	$(LD) $(LDFLAGS) $^ -o $@
+
+

png_to_vmu_lcd/main.c

@@ -0,0 +1,183 @@
+#include <stdio.h>
+#include <stdint.h>
+
+#include <png.h>
+
+int convertPNG(FILE *fptr_in, FILE *fptr_out);
+
+static void printusage(void)
+{
+	printf("Usage: ./png_to_vmu_lcd input_file output_file\n");
+	printf("\n");
+	printf("input_file must be a 48x32 pixels PNG file.\n");
+}
+
+int main(int argc, char **argv)
+{
+	FILE *fptr_in = NULL, *fptr_out = NULL;
+	uint8_t header[8];
+	int ret = 0;
+
+	if (argc < 3) {
+		printusage();
+		return 1;
+	}
+
+	fptr_in = fopen(argv[1], "rb");
+	if (!fptr_in) {
+		perror("fopen");
+		return 2;
+	}
+
+	if (8 != fread(header, 1, 8, fptr_in)) {
+		perror("fread");
+		ret = 3;
+		goto done;
+	}
+
+	if (png_sig_cmp(header, 0, 8)) {
+		fprintf(stderr, "Not a PNG file\n");
+		ret = 3;
+		goto done;
+	}
+
+	fptr_out = fopen(argv[2], "wb");
+	if (!fptr_out) {
+		perror("fopen outfile");
+		ret = 4;
+		goto done;
+	}
+
+	ret = convertPNG(fptr_in, fptr_out);
+
+done:
+	if (fptr_out) {
+		fclose(fptr_out);
+	}
+
+	if (fptr_in) {
+		fclose(fptr_in);
+	}
+
+	return ret;
+}
+
+int convertPNG(FILE *fptr_in, FILE *fptr_out)
+{
+	png_structp png_ptr;
+	png_infop info_ptr;
+	png_bytep *row_pointers;
+	int w,h,depth,color;
+	int ret;
+	int x,y;
+	int rotate180 = 1;
+	int bpp = 1;
+	unsigned char data, b;
+	
+	png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+	if (!png_ptr)
+		return -1;
+
+	info_ptr = png_create_info_struct(png_ptr);
+	if (!info_ptr) {
+		png_destroy_read_struct(&png_ptr, NULL, NULL);
+		return -1;
+	}
+	
+	if (setjmp(png_jmpbuf(png_ptr))) {
+		ret = -1;
+		goto done;
+	}
+
+	png_init_io(png_ptr, fptr_in);
+	png_set_sig_bytes(png_ptr, 8);
+
+	png_read_png(png_ptr, info_ptr, PNG_TRANSFORM_EXPAND | PNG_TRANSFORM_STRIP_16 | PNG_TRANSFORM_STRIP_ALPHA, NULL);
+
+	w = png_get_image_width(png_ptr, info_ptr);
+	h = png_get_image_height(png_ptr, info_ptr);
+	depth = png_get_bit_depth(png_ptr, info_ptr);
+	color = png_get_color_type(png_ptr, info_ptr);
+	
+	if (w != 48 || h != 32) {
+		fprintf(stderr, "Image is not 48 x 32 pixels. Current size: %d x %d. Please resize or rotate your image and try again.\n", w,h);
+		ret = -1;
+		goto done;
+	}
+	
+	printf("Image: %d x %d\n",w,h);
+	printf("Bit depth: %d\n", depth);
+	printf("Color type: %d\n", color);
+	row_pointers = png_get_rows(png_ptr, info_ptr);
+
+	switch(color)
+	{
+		case PNG_COLOR_TYPE_GRAY:
+			printf("Processing grayscale image\n");	
+			bpp = 1;
+			break;
+		case PNG_COLOR_TYPE_RGB:
+			printf("Processing color image\n");	
+			bpp = 3;
+			break;
+		default:
+			fprintf(stderr, "Unsupported color type\n");
+			ret = -1;
+			goto done;
+	}
+
+	data = 0;
+	b = 0x80;
+	if (rotate180)
+	{
+		for (y=h-1; y>=0; y--) {
+			for (x=w-1; x>=0; x--) {
+				
+				if (row_pointers[y][x*bpp]) {
+					printf("XX");
+				}
+				else {
+					printf("  ");
+					data |= b;
+				}
+
+				b >>= 1;
+				if (!b) {
+					fprintf(fptr_out, "0x%02X, ", data);
+					data = 0;
+					b = 0x80;
+				}
+			}
+			printf("\n");
+			fprintf(fptr_out, "\n");
+		}
+	}
+	else
+	{
+		for (y=0; y<h; y++) {
+			for (x=0; x<w; x++) {
+				if (row_pointers[y][x*bpp]) {
+					printf("XX");
+				}
+				else {
+					printf("  ");
+					data |= b;
+				}				 
+
+				b >>= 1;
+				if (!b) {
+					fprintf(fptr_out, "0x%02X, ", data);
+					data = 0;
+					b = 0x80;
+				}
+			}
+			printf("\n");
+			fprintf(fptr_out, "\n");
+		}
+	}	
+
+done:
+	png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+
+	return ret;
+}