return (a + b - 1) / b;
}
+
+/* -->> -->> -->> -->>
+
+ TGA IMAGE FORMAT
+
+ <<-- <<-- <<-- <<-- */
+
+// TGA header definition.
+#pragma pack(push,1) // Pack structure byte aligned
+typedef struct tga_header
+{
+ uint8 id_length; /* Image id field length */
+ uint8 colour_map_type; /* Colour map type */
+ uint8 image_type; /* Image type */
+ /*
+ ** Colour map specification
+ */
+ uint16 colour_map_index; /* First entry index */
+ uint16 colour_map_length; /* Colour map length */
+ uint8 colour_map_entry_size; /* Colour map entry size */
+ /*
+ ** Image specification
+ */
+ uint16 x_origin; /* x origin of image */
+ uint16 y_origin; /* u origin of image */
+ uint16 image_width; /* Image width */
+ uint16 image_height; /* Image height */
+ uint8 pixel_depth; /* Pixel depth */
+ uint8 image_desc; /* Image descriptor */
+} tga_header;
+#pragma pack(pop) // Return to normal structure packing alignment.
+
+int tga_readheader(FILE *fp, int *bits_per_pixel, int *width, int *height, int *flip_image)
+{
+ int palette_size;
+ tga_header tga ;
+
+ if (!bits_per_pixel || !width || !height || !flip_image)
+ return 0;
+
+ // Read TGA header
+ fread((uint8*)&tga, sizeof(tga_header), 1, fp);
+
+ *bits_per_pixel = tga.pixel_depth;
+
+ *width = tga.image_width;
+ *height = tga.image_height ;
+
+ // Ignore tga identifier, if present ...
+ if (tga.id_length)
+ {
+ uint8 *id = (uint8 *) malloc(tga.id_length);
+ fread(id, tga.id_length, 1, fp);
+ free(id);
+ }
+
+ // Test for compressed formats ... not yet supported ...
+ // Note :- 9 - RLE encoded palettized.
+ // 10 - RLE encoded RGB.
+ if (tga.image_type > 8)
+ {
+ fprintf(stderr, "Sorry, compressed tga files are not currently supported.\n");
+ return 0 ;
+ }
+
+ *flip_image = !(tga.image_desc & 32);
+
+ // Palettized formats are not yet supported, skip over the palette, if present ...
+ palette_size = tga.colour_map_length * (tga.colour_map_entry_size/8);
+
+ if (palette_size>0)
+ {
+ fprintf(stderr, "File contains a palette - not yet supported.");
+ fseek(fp, palette_size, SEEK_CUR);
+ }
+ return 1;
+}
+
+int tga_writeheader(FILE *fp, int bits_per_pixel, int width, int height, bool flip_image)
+{
+ tga_header tga;
+
+ if (!bits_per_pixel || !width || !height)
+ return 0;
+
+ memset(&tga, 0, sizeof(tga_header));
+
+ tga.pixel_depth = bits_per_pixel;
+ tga.image_width = width;
+ tga.image_height = height;
+ tga.image_type = 2; // Uncompressed.
+ tga.image_desc = 8; // 8 bits per component.
+
+ if (flip_image)
+ tga.image_desc |= 32;
+
+ // Write TGA header
+ fwrite((uint8*)&tga, sizeof(tga_header), 1, fp);
+
+ return 1;
+}
+
+opj_image_t* tgatoimage(const char *filename, opj_cparameters_t *parameters) {
+ FILE *f;
+ opj_image_t *image;
+ uint32 image_width, image_height, pixel_bit_depth;
+ uint32 x, y;
+ int flip_image=0;
+ opj_image_cmptparm_t cmptparm[4]; /* maximum 4 components */
+ int numcomps;
+ OPJ_COLOR_SPACE color_space;
+ bool mono ;
+ bool save_alpha;
+ int subsampling_dx, subsampling_dy;
+ int i;
+
+ f = fopen(filename, "rb");
+ if (!f) {
+ fprintf(stderr, "Failed to open %s for reading !!\n", filename);
+ return 0;
+ }
+
+ if (!tga_readheader(f, &pixel_bit_depth, &image_width, &image_height, &flip_image))
+ return NULL;
+
+ // We currently only support 24 & 32 bit tga's ...
+ if (!((pixel_bit_depth == 24) || (pixel_bit_depth == 32)))
+ return NULL;
+
+ /* initialize image components */
+ memset(&cmptparm[0], 0, 4 * sizeof(opj_image_cmptparm_t));
+
+ mono = (pixel_bit_depth == 8) || (pixel_bit_depth == 16); // Mono with & without alpha.
+ save_alpha = (pixel_bit_depth == 16) || (pixel_bit_depth == 32); // Mono with alpha, or RGB with alpha
+
+ if (mono) {
+ color_space = CLRSPC_GRAY;
+ numcomps = save_alpha ? 2 : 1;
+ }
+ else {
+ numcomps = save_alpha ? 4 : 3;
+ color_space = CLRSPC_SRGB;
+ }
+
+ subsampling_dx = parameters->subsampling_dx;
+ subsampling_dy = parameters->subsampling_dy;
+
+ for (i = 0; i < numcomps; i++) {
+ cmptparm[i].prec = 8;
+ cmptparm[i].bpp = 8;
+ cmptparm[i].sgnd = 0;
+ cmptparm[i].dx = subsampling_dx;
+ cmptparm[i].dy = subsampling_dy;
+ cmptparm[i].w = image_width;
+ cmptparm[i].h = image_height;
+ }
+
+ /* create the image */
+ image = opj_image_create(numcomps, &cmptparm[0], color_space);
+
+ if (!image)
+ return NULL;
+
+ /* set image offset and reference grid */
+ image->x0 = parameters->image_offset_x0;
+ image->y0 = parameters->image_offset_y0;
+ image->x1 = !image->x0 ? (image_width - 1) * subsampling_dx + 1 : image->x0 + (image_width - 1) * subsampling_dx + 1;
+ image->y1 = !image->y0 ? (image_height - 1) * subsampling_dy + 1 : image->y0 + (image_height - 1) * subsampling_dy + 1;
+
+ /* set image data */
+ for (y=0; y < image_height; y++)
+ {
+ int index;
+
+ if (flip_image)
+ index = (image_height-y-1)*image_width;
+ else
+ index = y*image_width;
+
+ if (numcomps==3)
+ {
+ for (x=0;x<image_width;x++)
+ {
+ uint8 r,g,b;
+ fread(&b, 1, 1, f);
+ fread(&g, 1, 1, f);
+ fread(&r, 1, 1, f);
+
+ image->comps[0].data[index]=r;
+ image->comps[1].data[index]=g;
+ image->comps[2].data[index]=b;
+ index++;
+ }
+ }
+ else if (numcomps==4)
+ {
+ for (x=0;x<image_width;x++)
+ {
+ uint8 r,g,b,a;
+ fread(&b, 1, 1, f);
+ fread(&g, 1, 1, f);
+ fread(&r, 1, 1, f);
+ fread(&a, 1, 1, f);
+
+ image->comps[0].data[index]=r;
+ image->comps[1].data[index]=g;
+ image->comps[2].data[index]=b;
+ image->comps[3].data[index]=a;
+ index++;
+ }
+ }
+ else {
+ fprintf(stderr, "Currently unsupported bit depth : %s\n", filename);
+ }
+ }
+ return image;
+}
+
+int imagetotga(opj_image_t * image, const char *outfile) {
+ int width, height, bpp, x, y;
+ bool write_alpha;
+ int i;
+ uint32 alpha_channel;
+ float r,g,b,a;
+ uint8 value;
+ float scale;
+ FILE *fdest;
+
+ fdest = fopen(outfile, "wb");
+ if (!fdest) {
+ fprintf(stderr, "ERROR -> failed to open %s for writing\n", outfile);
+ return 1;
+ }
+
+ for (i = 0; i < image->numcomps-1; i++) {
+ if ((image->comps[0].dx != image->comps[i+1].dx)
+ ||(image->comps[0].dy != image->comps[i+1].dy)
+ ||(image->comps[0].prec != image->comps[i+1].prec)) {
+ fprintf(stderr, "Unable to create a tga file with such J2K image charateristics.");
+ return 1;
+ }
+ }
+
+ width = int_ceildiv(image->x1-image->x0, image->comps[0].dx);
+ height = int_ceildiv(image->y1-image->y0, image->comps[0].dy);
+
+ // Mono with alpha, or RGB with alpha.
+ write_alpha = (image->numcomps==2) || (image->numcomps==4);
+
+ // Write TGA header
+ bpp = write_alpha ? 32 : 24;
+ if (!tga_writeheader(fdest, bpp, width, height, true))
+ return 1;
+
+ alpha_channel = image->numcomps-1;
+
+ scale = 255.0f / (float)((1<<image->comps[0].prec)-1);
+
+ for (y=0; y < height; y++) {
+ uint32 index=y*width;
+
+ for (x=0; x < width; x++, index++) {
+ r = (float)(image->comps[0].data[index]);
+
+ if (image->numcomps>2) {
+ g = (float)(image->comps[1].data[index]);
+ b = (float)(image->comps[2].data[index]);
+ }
+ else {// Greyscale ...
+ g = r;
+ b = r;
+ }
+
+ // TGA format writes BGR ...
+ value = (uint8)(b*scale);
+ fwrite(&value,1,1,fdest);
+
+ value = (uint8)(g*scale);
+ fwrite(&value,1,1,fdest);
+
+ value = (uint8)(r*scale);
+ fwrite(&value,1,1,fdest);
+
+ if (write_alpha) {
+ a = (float)(image->comps[alpha_channel].data[index]);
+ value = (uint8)(a*scale);
+ fwrite(&value,1,1,fdest);
+ }
+ }
+ }
+
+ return 0;
+}
+
/* -->> -->> -->> -->>
BMP IMAGE FORMAT
projects / openjpeg.git / blobdiff