Support reading CMYK, YCCK JPEGs

CHANGELOG.md

@@ -87,6 +87,7 @@ canvas.createJPEGStream() // new
  * Provide better, Node.js core-style coded errors for failed sys calls. (For
    example, provide an error with code 'ENOENT' if setting `img.src` to a path
    that does not exist.)
+ * Support reading CMYK, YCCK JPEGs.
 
 ### Added
  * Prebuilds (#992) with different libc versions to the prebuilt binary (#1140)

src/Image.cc

@@ -200,8 +200,8 @@ Image::clearData() {
     _surface = NULL;
   }
 
-  free(_data);
-  _data = NULL;
+  delete[] _data;
+  _data = nullptr;
 
   free(filename);
   filename = NULL;
@@ -356,7 +356,7 @@ Image::readPNG(void *c, uint8_t *data, unsigned int len) {
 
 Image::Image() {
   filename = NULL;
-  _data = NULL;
+  _data = nullptr;
   _data_len = 0;
   _surface = NULL;
   width = height = 0;
@@ -613,7 +613,7 @@ Image::loadGIFFromBuffer(uint8_t *buf, unsigned len) {
     return CAIRO_STATUS_INVALID_SIZE;
   }
 
-  uint8_t *data = (uint8_t *) malloc(naturalWidth * naturalHeight * 4);
+  uint8_t *data = new uint8_t[naturalWidth * naturalHeight * 4];
   if (!data) {
     GIF_CLOSE_FILE(gif);
     this->errorInfo.set(NULL, "malloc", errno);
@@ -719,7 +719,7 @@ Image::loadGIFFromBuffer(uint8_t *buf, unsigned len) {
   cairo_status_t status = cairo_surface_status(_surface);
 
   if (status) {
-    free(data);
+    delete[] data;
     return status;
   }
 
@@ -777,25 +777,36 @@ static void jpeg_mem_src (j_decompress_ptr cinfo, void* buffer, long nbytes) {
 
 #endif
 
+void Image::jpegToARGB(jpeg_decompress_struct* args, uint8_t* data, uint8_t* src, JPEGDecodeL decode) {
+  int stride = naturalWidth * 4;
+  for (int y = 0; y < naturalHeight; ++y) {
+    jpeg_read_scanlines(args, &src, 1);
+    uint32_t *row = (uint32_t*)(data + stride * y);
+    for (int x = 0; x < naturalWidth; ++x) {
+      int bx = args->output_components * x;
+      row[x] = decode(src + bx);
+    }
+  }
+}
+
 /*
  * Takes an initialised jpeg_decompress_struct and decodes the
  * data into _surface.
  */
 
 cairo_status_t
 Image::decodeJPEGIntoSurface(jpeg_decompress_struct *args) {
-  int stride = naturalWidth * 4;
-  cairo_status_t status;
-
-  uint8_t *data = (uint8_t *) malloc(naturalWidth * naturalHeight * 4);
+  cairo_status_t status = CAIRO_STATUS_SUCCESS;
+
+  uint8_t *data = new uint8_t[naturalWidth * naturalHeight * 4];
   if (!data) {
     jpeg_abort_decompress(args);
     jpeg_destroy_decompress(args);
     this->errorInfo.set(NULL, "malloc", errno);
     return CAIRO_STATUS_NO_MEMORY;
   }
 
-  uint8_t *src = (uint8_t *) malloc(naturalWidth * args->output_components);
+  uint8_t *src = new uint8_t[naturalWidth * args->output_components];
   if (!src) {
     free(data);
     jpeg_abort_decompress(args);
@@ -804,46 +815,56 @@ Image::decodeJPEGIntoSurface(jpeg_decompress_struct *args) {
     return CAIRO_STATUS_NO_MEMORY;
   }
 
-  for (int y = 0; y < naturalHeight; ++y) {
-    jpeg_read_scanlines(args, &src, 1);
-    uint32_t *row = (uint32_t *)(data + stride * y);
-    for (int x = 0; x < naturalWidth; ++x) {
-      if (args->jpeg_color_space == 1) {
-        uint32_t *pixel = row + x;
-        *pixel = 255 << 24
-          | src[x] << 16
-          | src[x] << 8
-          | src[x];
-      } else {
-        int bx = 3 * x;
-        uint32_t *pixel = row + x;
-        *pixel = 255 << 24
-          | src[bx + 0] << 16
-          | src[bx + 1] << 8
-          | src[bx + 2];
-      }
-    }
+  // These are the three main cases to handle. libjpeg converts YCCK to CMYK
+  // and YCbCr to RGB by default.
+  switch (args->out_color_space) {
+    case JCS_CMYK:
+      jpegToARGB(args, data, src, [](uint8_t const* src) {
+        uint16_t k = static_cast<uint16_t>(src[3]);
+        uint8_t r = k * src[0] / 255;
+        uint8_t g = k * src[1] / 255;
+        uint8_t b = k * src[2] / 255;
+        return 255 << 24 | r << 16 | g << 8 | b;
+      });
+      break;
+    case JCS_RGB:
+      jpegToARGB(args, data, src, [](uint8_t const* src) {
+        uint8_t r = src[0], g = src[1], b = src[2];
+        return 255 << 24 | r << 16 | g << 8 | b;
+      });
+      break;
+    case JCS_GRAYSCALE:
+      jpegToARGB(args, data, src, [](uint8_t const* src) {
+        uint8_t v = src[0];
+        return 255 << 24 | v << 16 | v << 8 | v;
+      });
+      break;
+    default:
+      this->errorInfo.set("Unsupported JPEG encoding");
+      status = CAIRO_STATUS_READ_ERROR;
+      break;
   }
 
-  _surface = cairo_image_surface_create_for_data(
-      data
-    , CAIRO_FORMAT_ARGB32
-    , naturalWidth
-    , naturalHeight
-    , cairo_format_stride_for_width(CAIRO_FORMAT_ARGB32, naturalWidth));
+  if (!status) {
+    _surface = cairo_image_surface_create_for_data(
+        data
+      , CAIRO_FORMAT_ARGB32
+      , naturalWidth
+      , naturalHeight
+      , cairo_format_stride_for_width(CAIRO_FORMAT_ARGB32, naturalWidth));
+  }
 
   jpeg_finish_decompress(args);
   jpeg_destroy_decompress(args);
   status = cairo_surface_status(_surface);
 
+  delete[] src;
+
   if (status) {
-    free(data);
-    free(src);
+    delete[] data;
     return status;
   }
 
-  free(src);
-
   _data = data;
 
   return CAIRO_STATUS_SUCCESS;
@@ -908,7 +929,7 @@ Image::decodeJPEGBufferIntoMimeSurface(uint8_t *buf, unsigned len) {
   // Data alloc
   // 8 pixels per byte using Alpha Channel format to reduce memory requirement.
   int buf_size = naturalHeight * cairo_format_stride_for_width(CAIRO_FORMAT_A1, naturalWidth);
-  uint8_t *data = (uint8_t *) malloc(buf_size);
+  uint8_t *data = new uint8_t[buf_size];
   if (!data) {
     this->errorInfo.set(NULL, "malloc", errno);
     return CAIRO_STATUS_NO_MEMORY;
@@ -928,7 +949,7 @@ Image::decodeJPEGBufferIntoMimeSurface(uint8_t *buf, unsigned len) {
   cairo_status_t status = cairo_surface_status(_surface);
 
   if (status) {
-    free(data);
+    delete[] data;
     return status;
   }
 

src/Image.h

@@ -10,6 +10,7 @@
 
 #include "Canvas.h"
 #include "CanvasError.h"
+#include <functional>
 
 #ifdef HAVE_JPEG
 #include <jpeglib.h>
@@ -34,7 +35,7 @@
   #endif
 #endif
 
-
+using JPEGDecodeL = std::function<uint32_t (uint8_t* const src)>;
 
 class Image: public Nan::ObjectWrap {
   public:
@@ -81,6 +82,7 @@ class Image: public Nan::ObjectWrap {
 #ifdef HAVE_JPEG
     cairo_status_t loadJPEGFromBuffer(uint8_t *buf, unsigned len);
     cairo_status_t loadJPEG(FILE *stream);
+    void jpegToARGB(jpeg_decompress_struct* args, uint8_t* data, uint8_t* src, JPEGDecodeL decode);
     cairo_status_t decodeJPEGIntoSurface(jpeg_decompress_struct *info);
 #if CAIRO_VERSION_MINOR >= 10
     cairo_status_t decodeJPEGBufferIntoMimeSurface(uint8_t *buf, unsigned len);
@@ -115,7 +117,7 @@ class Image: public Nan::ObjectWrap {
 
   private:
     cairo_surface_t *_surface;
-    uint8_t *_data;
+    uint8_t *_data = nullptr;
     int _data_len;
 #ifdef HAVE_RSVG
     RsvgHandle *_rsvg;