Yalantis/uCrop · error · CImgArgumentException

save_tiff(): Specified filename is (null).

Error message

save_tiff(): Specified filename is (null).

What it means

Raised by save_tiff()'s validation path when both the output FILE* and the filename are null, so no write target exists for the TIFF data; the message shows the filename argument as the literal '(null)'. This is the standard CImg sentinel guard for missing I/O arguments, not a libtiff encoding error — supply a filename or an open file handle.

Solutions

1. Pass a non-null filename string to save_tiff()
2. Validate the path before calling save_tiff()
3. Skip or branch the call when no TIFF output was requested

Example fix

// before
img.save_tiff(tiffName); // tiffName may be NULL
// after
if (tiffName) img.save_tiff(tiffName);
else cimg::warn("no TIFF output requested, skipping");

if (!filename || !*filename) throw std::invalid_argument("save_tiff requires a filename");

bool isValidFilename(const char *name) { return name != NULL && name[0] != '\0'; }

try { img.save_tiff(path.c_str()); } catch (CImgArgumentException &e) { /* missing destination */ }

When it happens

Trigger: Calling img.save_tiff(NULL) or save_tiff(someNullCharPtr); passing a null const char* from a config/variable that was never set; generic save() with an empty/null resolved name routed to the TIFF path.

Common situations: Batch exporters where the TIFF output field is optional but the call is unconditional; null from string::c_str misuse of a released buffer; uninitialized char* in C-style glue code (JNI).

Related errors

• load_cimg(): Specified filename is (null).
• load_tiff(): Specified filename is (null).
• save_pfm(): Specified filename is (null).
• save_pnk(): Specified filename is (null).
• save_pnm(): Specified filename is (null).

AI-assisted analysis of Yalantis/uCrop@f788b534b4 (2026-09-08). Data as JSON: /api/errors/286761b517e7dbea. Report an issue: GitHub.

Appendix: source

Thrown at ucrop/src/main/jni/CImg.h:62715

          24=PIXARFILM | 25=PIXARLOG | 26=SGILOG | 27=SGILOG24 | 28=T43 | 29=T85 | 30=THUNDERSCAN |
          31=WEBP | 32=ZSTD }</tt>
       \param[out] voxel_size Voxel size, to be stored in the filename.
       \param[out] description Description, to be stored in the filename.
       \param use_bigtiff Allow to save big tiff files (>4Gb).
       \note
       - libtiff support is enabled by defining the precompilation
        directive \c cimg_use_tiff.
       - When libtiff is enabled, 2D and 3D (multipage) several
        channel per pixel are supported for
        <tt>char,uchar,short,ushort,float</tt> and \c double pixel types.
       - If \c cimg_use_tiff is not defined at compile time the
        function uses CImg<T>&save_other(const char*).
     **/
    const CImg<T>& save_tiff(const char *const filename, const unsigned int compression_type=0,
                             const float *const voxel_size=0, const char *const description=0,
                             const bool use_bigtiff=true) const {
      if (!filename)
        throw CImgArgumentException(_cimg_instance
                                    "save_tiff(): Specified filename is (null).",
                                    cimg_instance);
      if (is_empty()) { cimg::fempty(0,filename); return *this; }

#ifdef cimg_use_tiff
      const bool
        _use_bigtiff = use_bigtiff && sizeof(ulongT)>=8 && size()*sizeof(T)>=1UL<<31; // No bigtiff for small images
      TIFF *tif = TIFFOpen(filename,_use_bigtiff?"w8":"w4");
      if (tif) {
        double val_min, val_max = (double)max_min(val_min);
        cimg_forZ(*this,z) _save_tiff(tif,z,z,compression_type,voxel_size,description,val_min,val_max);
        TIFFClose(tif);
      } else throw CImgIOException(_cimg_instance
                                   "save_tiff(): Failed to open file '%s' for writing.",
                                   cimg_instance,
                                   filename);
      return *this;
#else

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