{"record":{"id":"83813d435fce205a","repo":"Yalantis/uCrop","slug":"load-pnm-pnm-type-p-d-found-but-type-is-not","errorCode":null,"errorMessage":"load_pnm(): PNM type 'P%d' found, but type is not supported.","messagePattern":"load_pnm\\(\\): PNM type 'P(.+?)' found, but type is not supported\\.","errorType":"exception","errorClass":"CImgIOException","httpStatus":null,"severity":"error","filePath":"ucrop/src/main/jni/CImg.h","lineNumber":57737,"sourceCode":"          for (ulongT off = (ulongT)raw._width; off; --off) *(ptrd++) = (T)*(ptrs++);\n        }\n      } break;\n      case 9 : { // 2D/3D grey binary with float values (PINK extension)\n        CImg<floatT> raw;\n        assign(W,H,D,1);\n        T *ptrd = data(0,0,0,0);\n        for (longT to_read = (longT)size(); to_read>0; ) {\n          raw.assign(std::min(to_read,cimg_iobuffer));\n          cimg::fread(raw._data,raw._width,nfile);\n          to_read-=raw._width;\n          const float *ptrs = raw._data;\n          for (ulongT off = (ulongT)raw._width; off; --off) *(ptrd++) = (T)*(ptrs++);\n        }\n      } break;\n      default :\n        assign();\n        if (!file) cimg::fclose(nfile);\n        throw CImgIOException(_cimg_instance\n                              \"load_pnm(): PNM type 'P%d' found, but type is not supported.\",\n                              cimg_instance,\n                              filename?filename:\"(FILE*)\",ppm_type);\n      }\n      if (!file) cimg::fclose(nfile);\n      return *this;\n    }\n\n    //! Load image from a PFM file.\n    /**\n      \\param filename Filename, as a C-string.\n    **/\n    CImg<T>& load_pfm(const char *const filename) {\n      return _load_pfm(0,filename);\n    }\n\n    //! Load image from a PFM file \\newinstance.\n    static CImg<T> get_load_pfm(const char *const filename) {","sourceCodeStart":57719,"sourceCodeEnd":57755,"githubUrl":"https://github.com/Yalantis/uCrop/blob/f788b534b48c144edf786c8cddbf0e029e637804/ucrop/src/main/jni/CImg.h#L57719-L57755","documentation":"load_pnm() supports a fixed set of PNM subtypes (P1-P6 etc.) in its switch statement. If the parsed magic number corresponds to a type CImg does not implement (e.g. some P7/PAM variants or invalid digits), the default branch assigns() (empties the image) and throws CImgIOException naming the unsupported type.","triggerScenarios":"Loading a PNM file whose 'P<type>' magic is outside the supported switch cases: P7/PAM files, corrupt magic digits like 'P8'/'P9', or a magic token that sscanf parsed into an unexpected ppm_type value.","commonSituations":"Trying to load Netpbm PAM (P7) files with an older CImg version; corrupted first bytes changing 'P3' to 'P8'; custom tools emitting nonstandard PNM types.","solutions":["Convert the file to a supported type: `convert file.pam out.ppm` or `pamtopnm` before loading.","Use load_pnm only for P1-P6; use another loader for PAM/P7 data.","Check the magic bytes ('head -c 2') and confirm the type is one CImg supports in your version.","Upgrade CImg to a newer version that may support more PNM subtypes.","Catch CImgIOException and fall back to an external library (Netpbm, ImageMagick) for exotic types."],"exampleFix":"// before\nimg.load_pnm(\"capture.pam\"); // P7 not supported\n// after\nif (firstTwoBytes(path) == \"P7\") {\n  std::system(\"pamtopnm capture.pam > capture.pnm\");\n}\nimg.load_pnm(\"capture.pnm\");","handlingStrategy":"try-catch","validationCode":"bool pnmTypeSupported(const char* path) {\n  std::ifstream f(path, std::ios::binary);\n  char m[2] = {0}; f.read(m, 2);\n  return m[0]=='P' && m[1]>='1' && m[1]<='6';\n}","typeGuard":"bool isSupportedPnmType(char t) { return t >= '1' && t <= '6'; }","tryCatchPattern":"try {\n  img.load_pnm(path);\n} catch (cimg_library::CImgIOException& e) {\n  std::cerr << \"Unsupported PNM type, convert first: \" << e.what() << \"\\n\";\n  // fallback: shell out to pamtopnm / ImageMagick\n}","preventionTips":["Convert P7/PAM files to P1-P6 before loading","Pin and check the CImg version if you rely on specific PNM subtype support","Inspect magic bytes when ingesting third-party image files","Keep a fallback decoder for exotic formats"],"tags":["cimg","pnm","unsupported-format","image-loading"],"backgroundTag":"unsupported-operation","analyzedSha":"f788b534b48c144edf786c8cddbf0e029e637804","analyzedAt":"2026-09-08T08:36:04.887Z","contentChangedAt":"2026-09-08T08:36:04.887Z","schemaVersion":2},"datasetVersion":"2026-09-14T05:17:10.506Z"}