c++ mupdf 提取pdf文件里面图片
有时候需要从pdf中提取图片，那么此时可以使用mupdf库，如果采用vs2013版本，那么此时就需要考虑mupdf库的版本了，编译过多次之后，最终成功的版本是1.15.0，代码实例如下：
// TestPdf2png.cpp : 定义控制台应用程序的入口点。
//
#include "stdafx.h"
/*
* pdfextract -- the ultimate way to extract images and fonts from pdfs
*/
#include "mupdf/fitz.h"
#include "mupdf/pdf.h"
#include
#include
static pdf_document *doc = NULL;
static fz_context *ctx = NULL;
static int dorgb = 0;
static void usage(void)
{
fprintf(stderr, "usage: mutool extract [options] file.pdf [object numbers]\n");
fprintf(stderr, "\t-p\tpassword\n");
fprintf(stderr, "\t-r\tconvert images to rgb\n");
exit(1);
}
static int isimage(pdf_obj *obj)
{
pdf_obj *type = pdf_dict_get(ctx, obj, PDF_NAME(Subtype));
return pdf_name_eq(ctx, type, PDF_NAME(Image));
}
static int isfontdesc(pdf_obj *obj)
{
pdf_obj *type = pdf_dict_get(ctx, obj, PDF_NAME(Type));
return pdf_name_eq(ctx, type, PDF_NAME(FontDescriptor));
}
static void writepixmap(fz_context *ctx, fz_pixmap *pix, char *file, int dorgb)
{
char buf[1024];
fz_pixmap *rgb = NULL;
if (!pix)
return;
if (dorgb && pix->colorspace && pix->colorspace != fz_device_rgb(ctx))
{
rgb = fz_convert_pixmap(ctx, pix, fz_device_rgb(ctx), NULL, NULL, NULL /* FIXME */, 1);
pix = rgb;
}
if (pix->n - pix->alpha <= 3)
{
fz_snprintf(buf, sizeof(buf), "%s.png", file);
printf("extracting image %s\n", buf);
fz_save_pixmap_as_png(ctx, pix, buf);
}
else
{
fz_snprintf(buf, sizeof(buf), "%s.pam", file);
printf("extracting image %s\n", buf);
fz_save_pixmap_as_pam(ctx, pix, buf);
}
fz_drop_pixmap(ctx, rgb);
}
static void
writejpeg(fz_context *ctx, const unsigned char *data, size_t len, const char *file)
{
char buf[1024];
fz_output *out;
fz_snprintf(buf, sizeof(buf), "%s.jpg", file);
out = fz_new_output_with_path(ctx, buf, 0);
fz_try(ctx)
{
printf("extracting image %s\n", buf);
fz_write_data(ctx, out, data, len);
fz_close_output(ctx, out);
}
fz_always(ctx)
fz_drop_output(ctx, out);
fz_catch(ctx)
fz_rethrow(ctx);
}
static void saveimage(pdf_obj *ref)
{
fz_image *image = NULL;
fz_pixmap *pix = NULL;
char buf[32];
fz_compressed_buffer *cbuf;
int type;
fz_var(image);
fz_var(pix);
fz_try(ctx)
{
image = pdf_load_image(ctx, doc, ref);
cbuf = fz_compressed_image_buffer(ctx, image);
fz_snprintf(buf, sizeof(buf), "img-%04d", pdf_to_num(ctx, ref));
type = cbuf == NULL ? FZ_IMAGE_UNKNOWN : cbuf->params.type;
if (image->use_colorkey)
type = FZ_IMAGE_UNKNOWN;
if (image->use_decode)
type = FZ_IMAGE_UNKNOWN;
if (image->mask)
type = FZ_IMAGE_UNKNOWN;
if (dorgb)
{
enum fz_colorspace_type ctype = fz_colorspace_type(ctx, image->colorspace);
if (ctype != FZ_COLORSPACE_RGB && ctype != FZ_COLORSPACE_GRAY)
type = FZ_IMAGE_UNKNOWN;
}
if (type == FZ_IMAGE_JPEG)
{
unsigned char *data;
size_t len = fz_buffer_storage(ctx, cbuf->buffer, &data);
writejpeg(ctx, data, len, buf);
}
else
{
pix = fz_get_pixmap_from_image(ctx, image, NULL, NULL, 0, 0);
writepixmap(ctx, pix, buf, dorgb);
}
}
fz_always(ctx)
{
fz_drop_image(ctx, image);
fz_drop_pixmap(ctx, pix);
}
fz_catch(ctx)
fz_rethrow(ctx);
}
static void savefont(pdf_obj *dict)
{
char namebuf[1024];
fz_buffer *buf;
pdf_obj *stream = NULL;
pdf_obj *obj;
char *ext = "";
fz_output *out;
const char *fontname = "font";
size_t len;
unsigned char *data;
obj = pdf_dict_get(ctx, dict, PDF_NAME(FontName));
if (obj)
fontname = pdf_to_name(ctx, obj);
obj = pdf_dict_get(ctx, dict, PDF_NAME(FontFile));
if (obj)
{
stream = obj;
ext = "pfa";
}
obj = pdf_dict_get(ctx, dict, PDF_NAME(FontFile2));
if (obj)
{
stream = obj;
ext = "ttf";
}
obj = pdf_dict_get(ctx, dict, PDF_NAME(FontFile3));
if (obj)
{
stream = obj;
obj = pdf_dict_get(ctx, obj, PDF_NAME(Subtype));
if (obj && !pdf_is_name(ctx, obj))
fz_throw(ctx, FZ_ERROR_GENERIC, "invalid font descriptor subtype");
if (pdf_name_eq(ctx, obj, PDF_NAME(Type1C)))
ext = "cff";
else if (pdf_name_eq(ctx, obj, PDF_NAME(CIDFontType0C)))
ext = "cid";
else if (pdf_name_eq(ctx, obj, PDF_NAME(OpenType)))
ext = "otf";
else
fz_throw(ctx, FZ_ERROR_GENERIC, "unhandled font type '%s'", pdf_to_name(ctx, obj));
}
if (!stream)
{
fz_warn(ctx, "unhandled font type");
return;
}
buf = pdf_load_stream(ctx, stream);
len = fz_buffer_storage(ctx, buf, &data);
fz_try(ctx)
{
fz_snprintf(namebuf, sizeof(namebuf), "%s-%04d.%s", fontname, pdf_to_num(ctx, dict), ext);
printf("extracting font %s\n", namebuf);
out = fz_new_output_with_path(ctx, namebuf, 0);
fz_try(ctx)
{
fz_write_data(ctx, out, data, len);
fz_close_output(ctx, out);
}
fz_always(ctx)
fz_drop_output(ctx, out);
fz_catch(ctx)
fz_rethrow(ctx);
}
fz_always(ctx)
fz_drop_buffer(ctx, buf);
fz_catch(ctx)
fz_rethrow(ctx);
}
static void extractobject(int num)
{
pdf_obj *ref;
if (!doc)
fz_throw(ctx, FZ_ERROR_GENERIC, "no file specified");
fz_try(ctx)
{
ref = pdf_new_indirect(ctx, doc, num, 0);
if (isimage(ref))
saveimage(ref);
if (isfontdesc(ref))
savefont(ref);
}
fz_always(ctx)
pdf_drop_obj(ctx, ref);
fz_catch(ctx)
fz_warn(ctx, "ignoring object %d", num);
}
int _tmain(int argc, _TCHAR* argv[])
{
char *infile;
char *password = "";
int c, o;
infile = "C:\\Users\\14713\\Desktop\\1.pdf";
ctx = fz_new_context(NULL, NULL, FZ_STORE_UNLIMITED);
if (!ctx)
{
fprintf(stderr, "cannot initialise context\n");
exit(1);
}
doc = pdf_open_document(ctx, infile);
if (pdf_needs_password(ctx, doc))
if (!pdf_authenticate_password(ctx, doc, password))
fz_throw(ctx, FZ_ERROR_GENERIC, "cannot authenticate password: %s", infile);
int len = pdf_count_objects(ctx, doc);
for (o = 1; o < len; o++)
extractobject(o);
pdf_drop_document(ctx, doc);
fz_flush_warnings(ctx);
fz_drop_context(ctx);
return 0;
}