Yalantis/uCrop · warning

save_other(): File '%s', saving a volumetric image with an e

Error message

save_other(): File '%s', saving a volumetric image with an external call to GraphicsMagick only writes the first image slice.

What it means

When saving via an external GraphicsMagick process (save_graphicsmagick_external, called from save_other), CImg warns that volumetric images (_depth>1) are truncated to the first slice because the external command-line tool receives a temporary flat image file. Non-fatal; slices beyond z=0 are lost silently after the warning.

Source

Thrown at ucrop/src/main/jni/CImg.h:63718

      return *this;
    }

    //! Save image using GraphicsMagick's external binary.
    /**
       \param filename Filename, as a C-string.
       \param quality Image quality (expressed in percent), when the file format supports it.
       \note This method uses \c gm, an external executable binary provided by
         <a href="http://www.graphicsmagick.org">GraphicsMagick</a>.
       It must be installed for the method to succeed.
    **/
    const CImg<T>& save_graphicsmagick_external(const char *const filename, const unsigned int quality=100) const {
      if (!filename)
        throw CImgArgumentException(_cimg_instance
                                    "save_graphicsmagick_external(): Specified filename is (null).",
                                    cimg_instance);
      if (is_empty()) { cimg::fempty(0,filename); return *this; }
      if (_depth>1)
        cimg::warn(_cimg_instance
                   "save_other(): File '%s', saving a volumetric image with an external call to "
                   "GraphicsMagick only writes the first image slice.",
                   cimg_instance,filename);

#ifdef cimg_use_png
#define _cimg_sge_extension1 "png"
#define _cimg_sge_extension2 "png"
#else
#define _cimg_sge_extension1 "pgm"
#define _cimg_sge_extension2 "ppm"
#endif
      CImg<charT> command(1024), filename_tmp(256);
      do {
        cimg_snprintf(filename_tmp,filename_tmp._width,"%s%c%s.%s",
                      cimg::temporary_path(),cimg_file_separator,cimg::filenamerand(),
                      _spectrum==1?_cimg_sge_extension1:_cimg_sge_extension2);
      } while (cimg::path_exists(filename_tmp));

View on GitHub (pinned to f788b534b4)

Solutions

1. Compile CImg with the native codec macro for the target format (e.g. cimg_use_png, cimg_use_jpeg) so save_other uses the in-process codec
2. Save slices individually before delegating to the external tool
3. Use save_cimg() (native CImg format) for volumetric data
4. Install GraphicsMagick with multi-page support and switch to formats like TIFF/MIFF if volume support is needed

Example fix

// before
volume.save_other("out.png");       // external gm, only slice 0
// after
for (int z = 0; z < volume.depth(); ++z)
  volume.get_slice(z).save_png(cimg::format("out_%03d.png", z));

if (img.depth() > 1)
  for (int z = 0; z < img.depth(); ++z) img.get_slice(z).save(cimg::format("out_%03d.png", z));
else
  img.save("out.png");

bool is_2d(const cimg_library::CImg<T>& img) { return img.depth() == 1; }

try { img.save("out.png"); } catch (CImgException& e) { /* handle */ }

When it happens

Trigger: Calling save_other()/save_graphicsmagick_external() with _depth>1 when no native codec is compiled in for the target format (no cimg_use_png etc.), so CImg shells out to the 'gm convert' binary.

Common situations: Build without cimg_use_* flags forcing external-tool fallbacks; saving 3D data to PNG/JPEG via GraphicsMagick; CI/Docker images lacking native codec libraries.

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

• save_other(): File '%s', saving a volumetric image with an e
• save_other(): File '%s', saving a volumetric image with an e
• load_graphicsmagick_external(): Failed to load file '%s' wit
• save_graphicsmagick_external(): Specified filename is (null)
• save_pfm(): Instance is volumetric, only the first slice wil

AI-assisted analysis of Yalantis/uCrop@f788b534b4 (2026-09-08). Data as JSON: /api/errors/f1e0f4573d0acbf7. Report an issue: GitHub.