Add --keep-icc-profile and --jpeg-keep-all-metadata #26

formats/jpeg.cpp

@@ -7,6 +7,8 @@
 
 const uint8_t Jpeg::header_magic[] = { 0xFF, 0xD8, 0xFF };
 bool Jpeg::keep_exif_ = false;
+bool Jpeg::keep_icc_profile_ = false;
+bool Jpeg::keep_all_metadata_ = false;
 
 namespace {
 
@@ -51,9 +53,19 @@ size_t Jpeg::Leanify(size_t size_leanified /*= 0*/) {
   /* Specify data source for decompression */
   jpeg_mem_src(&srcinfo, fp_, size_);
 
-  if (keep_exif_) {
+  if (keep_exif_ || keep_all_metadata_) {
     jpeg_save_markers(&srcinfo, JPEG_APP0 + 1, 0xFFFF);
   }
+  if (keep_icc_profile_ || keep_all_metadata_) {
+    jpeg_save_markers(&srcinfo, JPEG_APP0 + 2, 0xFFFF);
+  }
+  if (keep_all_metadata_) {
+    // Save the rest APPn markers.
+    for (int i = 3; i < 16; i++)
+      jpeg_save_markers(&srcinfo, JPEG_APP0 + i, 0xFFFF);
+    // Save comments.
+    jpeg_save_markers(&srcinfo, JPEG_COM, 0xFFFF);
+  }
 
   (void)jpeg_read_header(&srcinfo, true);
 
@@ -79,11 +91,9 @@ size_t Jpeg::Leanify(size_t size_leanified /*= 0*/) {
   /* Start compressor (note no image data is actually written here) */
   jpeg_write_coefficients(&dstinfo, coef_arrays);
 
-  if (keep_exif_) {
+  if (keep_exif_ || keep_icc_profile_ || keep_all_metadata_) {
     for (auto marker = srcinfo.marker_list; marker; marker = marker->next) {
-      if (marker->marker == JPEG_APP0 + 1) {
-        jpeg_write_marker(&dstinfo, marker->marker, marker->data, marker->data_length);
-      }
+      jpeg_write_marker(&dstinfo, marker->marker, marker->data, marker->data_length);
     }
   }
 

formats/jpeg.h

@@ -14,6 +14,8 @@ class Jpeg : public Format {
 
   static const uint8_t header_magic[3];
   static bool keep_exif_;
+  static bool keep_icc_profile_;
+  static bool keep_all_metadata_;
 };
 
 #endif  // FORMATS_JPEG_H_

formats/png.cpp

@@ -16,6 +16,7 @@ using std::endl;
 using std::vector;
 
 const uint8_t Png::header_magic[] = { 0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A };
+bool Png::keep_icc_profile_ = false;
 
 size_t Png::Leanify(size_t size_leanified /*= 0*/) {
   // header
@@ -50,37 +51,44 @@ size_t Png::Leanify(size_t size_leanified /*= 0*/) {
     // read chunk type
     chunk_type = *(uint32_t*)(p_read + 4);
 
-    // judge the case of first letter
-    // remove all ancillary chunks except tRNS and APNG chunks and npTc
-    // tRNS has transparency information
-    if (chunk_type & 0x20) {
+    if (chunk_type == 0x54414449) {
+      // save IDAT chunk address
+      idat_addr = p_write;
+    }
+
+    bool should_remove = [&]() {
+      // Check the case of first letter, keep all critical chunks.
+      if ((chunk_type & 0x20) == 0)
+        return false;
+
+      // Remove all ancillary chunks except the following.
       switch (chunk_type) {
         case 0x4C546361:  // acTL     APNG
         case 0x4C546366:  // fcTL     APNG
         case 0x54416466:  // fdAT     APNG    TODO: use Zopfli to recompress fdAT
         case 0x6354706E:  // npTc     Android 9Patch images (*.9.png)
-          break;
+          return false;
 
         case 0x534E5274:  // tRNS     transparent
-          // tRNS must be before IDAT according to PNG spec
-          if (idat_addr == nullptr)
-            break;
-          // Fallthrough to remove it
+                          // tRNS must be before IDAT according to PNG spec
+          return idat_addr != nullptr;
+        case 0x50434369:  // iCCP     ICC profile
+          return !keep_icc_profile_;
         default:
-          if (is_verbose) {
-            // chunk name
-            for (int i = 4; i < 8; i++)
-              cout << static_cast<char>(p_read[i]);
-
-            cout << " chunk removed, " << chunk_length << " bytes." << endl;
-          }
-          // remove this chunk
-          p_read += chunk_length;
-          continue;
+          return true;
       }
-    } else if (chunk_type == 0x54414449) {
-      // save IDAT chunk address
-      idat_addr = p_write;
+    }();
+    if (should_remove) {
+      if (is_verbose) {
+        // chunk name
+        for (int i = 4; i < 8; i++)
+          cout << static_cast<char>(p_read[i]);
+
+        cout << " chunk removed, " << chunk_length << " bytes." << endl;
+      }
+      // remove this chunk
+      p_read += chunk_length;
+      continue;
     }
 
     // move this chunk
@@ -103,6 +111,8 @@ size_t Png::Leanify(size_t size_leanified /*= 0*/) {
     zopflipng_options.lossy_transparent = true;
     // see the switch above for information about these chunks
     zopflipng_options.keepchunks = { "acTL", "fcTL", "fdAT", "npTc" };
+    if (keep_icc_profile_)
+      zopflipng_options.keepchunks.push_back("iCCP");
     zopflipng_options.num_iterations = iterations;
     zopflipng_options.num_iterations_large = iterations;
 

formats/png.h

@@ -14,6 +14,7 @@ class Png : public Format {
   size_t Leanify(size_t size_leanified = 0) override;
 
   static const uint8_t header_magic[8];
+  static bool keep_icc_profile_;
 };
 
 #endif  // FORMATS_PNG_H_

main.cpp

@@ -14,6 +14,7 @@
 #include "version.h"
 
 #include "formats/jpeg.h"
+#include "formats/png.h"
 
 using std::cerr;
 using std::cout;
@@ -85,7 +86,11 @@ void PrintInfo() {
           "  -f, --fastmode                Fast mode, no recompression.\n"
           "  -q, --quiet                   No output to stdout.\n"
           "  -v, --verbose                 Verbose output.\n"
-          "  --keep-exif                   Do not remove Exif.\n";
+          "  --keep-exif                   Do not remove Exif.\n"
+          "  --keep-icc-profile            Do not remove ICC profile.\n"
+          "\n"
+          "JPEG specific option:\n"
+          "  --jpeg-keep-all-metadata      Do not remove any metadata or comments in JPEG.\n";
 
   PauseIfNotTerminal();
 }
@@ -169,6 +174,13 @@ int main(int argc, char* argv[]) {
           } else if (STRCMP(argv[i] + j + 1, "keep-exif") == 0) {
             j += 9;
             Jpeg::keep_exif_ = true;
+          } else if (STRCMP(argv[i] + j + 1, "keep-icc-profile") == 0) {
+            j += 16;
+            Jpeg::keep_icc_profile_ = true;
+            Png::keep_icc_profile_ = true;
+          } else if (STRCMP(argv[i] + j + 1, "jpeg-keep-all-metadata") == 0) {
+            j += 22;
+            Jpeg::keep_all_metadata_ = true;
           } else {
 #ifdef _WIN32
             char mbs[64] = { 0 };