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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 <stdlib.h>
#include <stdio.h>
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;
}
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