Correct fix for issue #31

See discussion at tesseract-ocr/tesseract#3317
adaptech-cz · Mar 4, 2021 · 757271e · 757271e
2 parents 339a4a9 + a8e7661
commit 757271e
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Showing 3 changed files with 46 additions and 16 deletions.
diff --git a/tesseract4android/src/main/cpp/leptonica/CMakeLists.txt b/tesseract4android/src/main/cpp/leptonica/CMakeLists.txt
@@ -67,7 +67,7 @@ add_definitions(-DANDROID_BUILD)
 add_definitions(-DHAVE_LIBJPEG=1)
 add_definitions(-DHAVE_LIBPNG=1)
 add_definitions(-DHAVE_LIBZ=1)
-# TODO: Enable this when we use minSdkVersion 23 or higher and remove workaround in pdfrenderer.cpp
+# TODO: Enable this when we use minSdkVersion 23 or higher
 #add_definitions(-DHAVE_FMEMOPEN=1)
 
 # Ignore some warnings during build

diff --git a/tesseract4android/src/main/cpp/leptonica/src/src/pdfio2.c b/tesseract4android/src/main/cpp/leptonica/src/src/pdfio2.c
@@ -807,29 +807,65 @@ PIXCMAP      *cmap = NULL;
  *           ~ 0 for binary data (not permitted in PostScript)
  *           ~ 1 for ascii85 (5 for 4) encoded binary data
  *               (not permitted in pdf)
- *      (2) Do not free the data.  l_generateJpegDataMem() will free
- *          the data if the data is invalid, or if it does not use
- *          ascii encoding.
+ *      (2) Most of this function is repeated in l_generateJpegMemData(),
+ *          which is required in pixacompFastConvertToPdfData().
  * </pre>
  */
 L_COMP_DATA *
 l_generateJpegData(const char  *fname,
                    l_int32      ascii85flag)
 {
-l_uint8      *data = NULL;
-size_t        nbytes;
+    char         *data85 = NULL;  /* ascii85 encoded jpeg compressed file */
+    l_uint8      *data = NULL;
+    l_int32       w, h, xres, yres, bps, spp;
+    size_t        nbytes, nbytes85;
+    L_COMP_DATA  *cid;
+    FILE         *fp;
 
     PROCNAME("l_generateJpegData");
 
     if (!fname)
         return (L_COMP_DATA *)ERROR_PTR("fname not defined", procName, NULL);
 
-        /* The returned jpeg data in memory is the entire jpeg file,
-         * which starts with ffd8 and ends with ffd9 */
+    /* Read the metadata */
+    if (readHeaderJpeg(fname, &w, &h, &spp, NULL, NULL))
+        return (L_COMP_DATA *)ERROR_PTR("bad jpeg metadata", procName, NULL);
+    bps = 8;
+    if ((fp = fopenReadStream(fname)) == NULL)
+        return (L_COMP_DATA *)ERROR_PTR("stream not opened", procName, NULL);
+    fgetJpegResolution(fp, &xres, &yres);
+    fclose(fp);
+
+    /* Read the entire jpeg file.  The returned jpeg data in memory
+     * starts with ffd8 and ends with ffd9 */
     if ((data = l_binaryRead(fname, &nbytes)) == NULL)
         return (L_COMP_DATA *)ERROR_PTR("data not extracted", procName, NULL);
 
-    return l_generateJpegDataMem(data, nbytes, ascii85flag);
+    /* Optionally, encode the compressed data */
+    if (ascii85flag == 1) {
+        data85 = encodeAscii85(data, nbytes, &nbytes85);
+        LEPT_FREE(data);
+        if (!data85)
+            return (L_COMP_DATA *)ERROR_PTR("data85 not made", procName, NULL);
+        else
+            data85[nbytes85 - 1] = '\0';  /* remove the newline */
+    }
+
+    cid = (L_COMP_DATA *)LEPT_CALLOC(1, sizeof(L_COMP_DATA));
+    if (ascii85flag == 0) {
+        cid->datacomp = data;
+    } else {  /* ascii85 */
+        cid->data85 = data85;
+        cid->nbytes85 = nbytes85;
+    }
+    cid->type = L_JPEG_ENCODE;
+    cid->nbytescomp = nbytes;
+    cid->w = w;
+    cid->h = h;
+    cid->bps = bps;
+    cid->spp = spp;
+    cid->res = xres;
+    return cid;
 }
 
 

diff --git a/tesseract4android/src/main/cpp/tesseract/src/src/api/pdfrenderer.cpp b/tesseract4android/src/main/cpp/tesseract/src/src/api/pdfrenderer.cpp
@@ -675,14 +675,8 @@ bool TessPDFRenderer::imageToPDFObj(Pix *pix,
 
   L_Compressed_Data *cid = nullptr;
 
-#ifdef __ANDROID__ // Remove this when we use minSdkVersion 23 or higher
-  bool flateEncode = true;
-#else
-  bool flateEncode = pixGetInputFormat(pix) == IFF_PNG;
-#endif
-
   int sad = 0;
-  if (flateEncode)
+  if (pixGetInputFormat(pix) == IFF_PNG)
     sad = pixGenerateCIData(pix, L_FLATE_ENCODE, 0, 0, &cid);
   if (!cid) {
     sad = l_generateCIDataForPdf(filename, pix, jpg_quality, &cid);