{"record":{"id":"e2e3b7db24b91580","repo":"Yalantis/uCrop","slug":"load-jpeg-failed-to-load-jpeg-data-from-file","errorCode":null,"errorMessage":"load_jpeg(): Failed to load JPEG data from file '%s'.","messagePattern":"load_jpeg\\(\\): Failed to load JPEG data from file '(.+?)'\\.","errorType":"exception","errorClass":"CImgIOException","httpStatus":null,"severity":"error","filePath":"ucrop/src/main/jni/CImg.h","lineNumber":57055,"sourceCode":"      jerr.original.error_exit = _cimg_jpeg_error_exit;\n      if (setjmp(jerr.setjmp_buffer)) { // JPEG error\n        if (!file) cimg::fclose(nfile);\n        throw CImgIOException(_cimg_instance\n                             \"load_jpeg(): Error message returned by libjpeg: %s.\",\n                             cimg_instance,jerr.message);\n      }\n\n      jpeg_create_decompress(&cinfo);\n      jpeg_stdio_src(&cinfo,nfile);\n      jpeg_read_header(&cinfo,TRUE);\n      jpeg_start_decompress(&cinfo);\n\n      if (cinfo.output_components!=1 && cinfo.output_components!=3 && cinfo.output_components!=4) {\n        if (!file) {\n          cimg::fclose(nfile);\n          return load_other(nfilename);\n        } else\n          throw CImgIOException(_cimg_instance\n                                \"load_jpeg(): Failed to load JPEG data from file '%s'.\",\n                                cimg_instance,nfilename?nfilename:\"(FILE*)\");\n      }\n      CImg<ucharT> buffer(cinfo.output_width*cinfo.output_components);\n      JSAMPROW row_pointer[1];\n      try { assign(cinfo.output_width,cinfo.output_height,1,cinfo.output_components); }\n      catch (...) { if (!file) cimg::fclose(nfile); throw; }\n      T *ptr_r = _data, *ptr_g = _data + 1UL*_width*_height, *ptr_b = _data + 2UL*_width*_height,\n        *ptr_a = _data + 3UL*_width*_height;\n      while (cinfo.output_scanline<cinfo.output_height) {\n        *row_pointer = buffer._data;\n        if (jpeg_read_scanlines(&cinfo,row_pointer,1)!=1) {\n          cimg::warn(_cimg_instance\n                     \"load_jpeg(): Incomplete data in file '%s'.\",\n                     cimg_instance,nfilename?nfilename:\"(FILE*)\");\n          break;\n        }\n        const unsigned char *ptrs = buffer._data;","sourceCodeStart":57037,"sourceCodeEnd":57073,"githubUrl":"https://github.com/Yalantis/uCrop/blob/f788b534b48c144edf786c8cddbf0e029e637804/ucrop/src/main/jni/CImg.h#L57037-L57073","documentation":"After jpeg_start_decompress, CImg only handles 1 (grayscale), 3 (RGB), or 4 (CMYK) output components; any other channel count triggers this error when reading from a FILE* (with a filename it silently falls back to load_other). It indicates the JPEG's color space/configuration is not directly decodable.","triggerScenarios":"load_jpeg(FILE*) on JPEGs whose decompressed output_components is not 1/3/4, e.g. unusual color spaces, separated CMYK with Adobe markers producing odd counts, or non-JPEG data misdetected.","commonSituations":"Scanned/print-shop CMYK JPEGs with Adobe APP14 markers, images transcoded by odd tools, wrong-format files named .jpg.","solutions":["Convert the JPEG to standard RGB (e.g. convert in.jpg -colorspace sRGB out.jpg) and reload","Pass a filename instead of a FILE* so CImg can fall back to load_other()","Re-export the image from a standard encoder","Use an alternate decoder supporting exotic color spaces (libvips, libmagick)"],"exampleFix":"// before\nstd::FILE* f = fopen(\"cmyk.jpg\",\"rb\");\nimg.load_jpeg(f);\n// after\nimg.load_jpeg(\"cmyk.jpg\"); // allows fallback\n// or convert first: convert cmyk.jpg -colorspace sRGB cmyk_rgb.jpg\nimg.load_jpeg(\"cmyk_rgb.jpg\");","handlingStrategy":"fallback","validationCode":"// prefer filename-based load so CImg can fall back automatically\nimg.load_jpeg(\"image.jpg\"); // not load_jpeg(FILE*)\n","typeGuard":null,"tryCatchPattern":"try { img.load_jpeg(file, filename); }\ncatch (CImgIOException&) { img.load(\"image_converted.png\"); }","preventionTips":["Convert exotic CMYK/sep JPEGs to sRGB before loading","Use filename-based load to enable automatic fallback decoding","Standardize uploads to RGB JPEG or PNG","Pre-validate with an independent decoder if inputs are untrusted"],"tags":["jpeg","image-loading","color-space","libjpeg","cimg"],"backgroundTag":"unexpected-api-response-shape","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"}