Yalantis/uCrop · error · CImgIOException

load_pandore(): PANDORE header not found in file '%s'.

Error message

load_pandore(): PANDORE header not found in file '%s'.

What it means

PANDORE files begin with a magic header containing the string "PANDORE" within the first bytes. _load_pandore() reads 12 bytes and case-insensitively compares the first 7 with "PANDORE"; on mismatch it throws CImgIOException. This is a format-detection failure — the file is not a PANDORE file (or is unreadable/empty).

Source

Thrown at ucrop/src/main/jni/CImg.h:58852

        if (sizeof(stype1)==ltype) { __cimg_load_pandore_case(nbdim,nwidth,nheight,ndepth,dim,stype1); } \
        else if (sizeof(stype2)==ltype) { __cimg_load_pandore_case(nbdim,nwidth,nheight,ndepth,dim,stype2); } \
        else if (sizeof(stype3)==ltype) { __cimg_load_pandore_case(nbdim,nwidth,nheight,ndepth,dim,stype3); } \
        else throw CImgIOException(_cimg_instance \
                                   "load_pandore(): Unknown pixel datatype in file '%s'.", \
                                   cimg_instance, \
                                   filename?filename:"(FILE*)"); }
      if (!file && !filename)
        throw CImgArgumentException(_cimg_instance
                                    "load_pandore(): Specified filename is (null).",
                                    cimg_instance);

      const ulongT fsiz = file?(ulongT)cimg_max_buf_size:(ulongT)cimg::fsize(filename);
      std::FILE *const nfile = file?file:cimg::fopen(filename,"rb");
      CImg<charT> header(32);
      cimg::fread(header._data,12,nfile);
      if (cimg::strncasecmp("PANDORE",header,7)) {
        if (!file) cimg::fclose(nfile);
        throw CImgIOException(_cimg_instance
                              "load_pandore(): PANDORE header not found in file '%s'.",
                              cimg_instance,
                              filename?filename:"(FILE*)");
      }
      unsigned int imageid, dims[8] = {};
      int ptbuf[4] = {};
      cimg::fread(&imageid,1,nfile);
      const bool endian = imageid>255;
      if (endian) cimg::invert_endianness(imageid);
      cimg::fread(header._data,20,nfile);

      switch (imageid) {
      case 2 : _cimg_load_pandore_case(2,dims[1],1,1,1,unsigned char,unsigned char,unsigned char,1); break;
      case 3 : _cimg_load_pandore_case(2,dims[1],1,1,1,long,int,short,4); break;
      case 4 : _cimg_load_pandore_case(2,dims[1],1,1,1,double,float,float,4); break;
      case 5 : _cimg_load_pandore_case(3,dims[2],dims[1],1,1,unsigned char,unsigned char,unsigned char,1); break;
      case 6 : _cimg_load_pandore_case(3,dims[2],dims[1],1,1,long,int,short,4); break;
      case 7 : _cimg_load_pandore_case(3,dims[2],dims[1],1,1,double,float,float,4); break;

View on GitHub (pinned to f788b534b4)

Solutions

  1. Confirm the file really is PANDORE format (open the first bytes; they must contain "PANDORE")
  2. Use the correct loader (load(), load_other(), load_png/jpeg...) — CImg's load() auto-detects by magic bytes
  3. Re-download/re-export the file if it is truncated or empty
  4. Check file permissions/size before loading

Example fix

// before
img.load_pandore(maybe_pan); // throws if not PANDORE
// after
std::ifstream in(maybe_pan, std::ios::binary);
char head[8] = {};
in.read(head, 7);
if (!in || cimg::strncasecmp("PANDORE", head, 7))
  img.load(maybe_pan);   // auto-detect instead
else
  img.load_pandore(maybe_pan);
Defensive patterns

Strategy: validation

Validate before calling

std::ifstream f(path, std::ios::binary);
char head[8] = {}; f.read(head, 7);
if (!f || cimg::strncasecmp("PANDORE", head, 7))
  throw std::runtime_error("not a PANDORE file; use auto-detecting load()");

Try / catch

try { img.load_pandore(path); } catch (const cimg_library::CImgIOException &e) { /* bad header */ img.load(path); // auto-detect by magic bytes
}

Prevention

When it happens

Trigger: Loading a file that is not actually PANDORE format (renamed JPEG/PNG/text); loading an empty or truncated file (fewer than 12 bytes); a corrupted header.

Common situations: Wrong file selected by wildcard/glob; files renamed with .pan extension without conversion; interrupted writes producing empty files; using load_pandore when the format is actually another CImg loader's job.

Understand the failure class

Background: "File not found" and ENOENT errors: why libraries can't find a file that should exist — this error's family across 50 libraries.

Related errors

AI-assisted analysis of Yalantis/uCrop@f788b534b4 (2026-09-08). Data as JSON: /api/errors/d41aabb342ce7977. Report an issue: GitHub.