image-headers - npm Package Compare versions

Comparing version 0.1.0 to 0.2.0

lib/image_headers.js

@@ -32,5 +32,11 @@ // Generated by CoffeeScript 1.4.0
       this.stream_index = 0;
-      this.marker = 0;
-      this.marker_offset = 0;
-      this.marker_size = 0;
+      this.jpeg = {
+        marker: 0,
+        marker_offset: 0,
+        marker_size: 0
+      };
+      this.png = {
+        start: 0,
+        length: 0
+      };
       this.height = null;
@@ -74,23 +80,27 @@ this.width = null;
       local_this = this;
-      if ((this.exif_buffer != null) && this.exif_buffer.toString("utf-8", 0, 4) === "Exif") {
-        return new exif.ExifImage({
-          exif_buffer: this.exif_buffer
-        }, function(err, exif_data) {
-          var orientation_tag, temp_w;
-          if ((exif_data != null) && (exif_data.image != null)) {
-            orientation_tag = exif_data.image.filter(function(tag) {
-              return tag.tagName === "Orientation";
-            });
-            if (orientation_tag.length === 1) {
-              local_this.orientation = orientation_tag[0].value;
-              if (local_this.orientation === 6 || local_this.orientation === 8) {
-                temp_w = local_this.width;
-                local_this.width = local_this.height;
-                local_this.height = temp_w;
+      if (this.mode === ImageHeaders.modes.jpeg) {
+        if ((this.exif_buffer != null) && this.exif_buffer.toString("utf-8", 0, 4) === "Exif") {
+          return new exif.ExifImage({
+            exif_buffer: this.exif_buffer
+          }, function(err, exif_data) {
+            var orientation_tag, temp_w;
+            if ((exif_data != null) && (exif_data.image != null)) {
+              orientation_tag = exif_data.image.filter(function(tag) {
+                return tag.tagName === "Orientation";
+              });
+              if (orientation_tag.length === 1) {
+                local_this.orientation = orientation_tag[0].value;
+                if (local_this.orientation === 6 || local_this.orientation === 8) {
+                  temp_w = local_this.width;
+                  local_this.width = local_this.height;
+                  local_this.height = temp_w;
+                }
               }
             }
-          }
-          local_this.exif_data = exif_data;
-          return callback(err, local_this);
-        });
+            local_this.exif_data = exif_data;
+            return callback(err, local_this);
+          });
+        }
+      } else {
+        return callback(null, local_this);
       }
@@ -116,6 +126,6 @@ };
       var length, position;
-      if (this.marker === 0 && b === 255) {
-        this.marker = b;
+      if (this.jpeg.marker === 0 && b === 255) {
+        this.jpeg.marker = b;
         return;
-      } else if (this.marker === 255) {
+      } else if (this.jpeg.marker === 255) {
         switch (b) {
@@ -135,28 +145,29 @@ case 0x00:
           case 0xFF:
-            this.clear_marker();
+            this.clear_jpeg_marker();
             return;
           default:
-            this.marker = b;
-            this.marker_offset = i;
-            this.marker_size = 0;
+            this.jpeg.marker = b;
+            this.jpeg.marker_offset = i;
+            this.jpeg.marker_size = 0;
         }
       }
-      if (this.marker === 0xDA && this.marker_offset - i === 0) {
+      if (this.jpeg.marker === 0xDA && this.jpeg.marker_offset - i === 0) {
+        this.finished = true;
         return;
       }
-      position = i - this.marker_offset;
+      position = i - this.jpeg.marker_offset;
       if (position === 2) {
-        length = this.buffer.readUInt16BE(this.marker_offset + 1);
-        this.marker_size = length;
-        switch (this.marker) {
+        length = this.buffer.readUInt16BE(this.jpeg.marker_offset + 1);
+        this.jpeg.marker_size = length;
+        switch (this.jpeg.marker) {
           case 0xE1:
             if (!(this.exif_buffer != null)) {
-              this.exif_bytes = this.marker_size - 2;
+              this.exif_bytes = this.jpeg.marker_size - 2;
               this.exif_buffer = new Buffer(this.exif_bytes);
-              return this.clear_marker();
+              return this.clear_jpeg_marker();
             }
         }
       } else {
-        if (this.marker_size > 0 && position === this.marker_size) {
-          switch (this.marker) {
+        if (this.jpeg.marker_size > 0 && position === this.jpeg.marker_size) {
+          switch (this.jpeg.marker) {
             case 0xC0:
@@ -177,3 +188,3 @@ case 0xC1:
           }
-          return this.clear_marker();
+          return this.clear_jpeg_marker();
         }
@@ -183,4 +194,42 @@ }
 
+    ImageHeaders.prototype.check_gif_state = function(b, i) {
+      if (i === 10) {
+        this.width = this.buffer.readUInt16LE(6);
+        this.height = this.buffer.readUInt16LE(8);
+        return this.finished = true;
+      }
+    };
+
+    ImageHeaders.prototype.check_png_state = function(b, i) {
+      var length, offset;
+      if (i < 8) {
+        return;
+      }
+      if (this.png.start === 0) {
+        this.png.start = i;
+        return 0;
+      }
+      offset = i - this.png.start;
+      switch (offset) {
+        case 3:
+          length = this.buffer.readUInt32BE(this.png.start);
+          return this.png.length = length;
+        case 7:
+          return this.png.marker = this.buffer.toString("utf8", this.png.start + 4, this.png.start + 8);
+        case this.png.length + 8:
+          if (this.png.marker === "IHDR") {
+            this.width = this.buffer.readUInt32BE(this.png.start + 8);
+            this.height = this.buffer.readUInt32BE(this.png.start + 12);
+            return this.finished = true;
+          }
+          break;
+        case this.png.length + 12:
+          return this.clear_png_marker();
+      }
+    };
+
+    ImageHeaders.prototype.check_tiff_state = function(b, i) {};
+
     ImageHeaders.prototype.identify_format = function(b) {
-      var i, _i, _ref, _results;
+      var buf_as_string, i, _i, _ref, _results;
       if (this.stream_index === 1) {
@@ -190,2 +239,13 @@ if (this.buffer[0] === 0xFF && this.buffer[1] === 0xD8) {
         }
+      } else if (this.stream_index === 2) {
+        buf_as_string = this.buffer.toString("utf8", 0, 3);
+        if (buf_as_string === "GIF") {
+          this.mode = ImageHeaders.modes.gif;
+        } else if (buf_as_string === "II*" || buf_as_string === "MM*") {
+          this.mode = ImageHeaders.modes.tiff;
+        }
+      } else if (this.stream_index === 7) {
+        if (this.buffer.toString("hex", 0, 8) === "89504e470d0a1a0a") {
+          this.mode = ImageHeaders.modes.png;
+        }
       }
@@ -205,13 +265,19 @@ if (this.stream_index > 10) {
 
-    ImageHeaders.prototype.clear_marker = function() {
-      this.marker = 0;
-      this.marker_offset = 0;
-      return this.marker_size = 0;
+    ImageHeaders.prototype.clear_jpeg_marker = function() {
+      this.jpeg.marker = 0;
+      this.jpeg.marker_offset = 0;
+      return this.jpeg.marker_size = 0;
     };
 
     ImageHeaders.prototype.parse_jpeg_sofn = function() {
-      this.height = this.buffer.readUInt16BE(this.marker_offset + 4);
-      return this.width = this.buffer.readUInt16BE(this.marker_offset + 6);
+      this.height = this.buffer.readUInt16BE(this.jpeg.marker_offset + 4);
+      return this.width = this.buffer.readUInt16BE(this.jpeg.marker_offset + 6);
     };
 
+    ImageHeaders.prototype.clear_png_marker = function() {
+      this.png.start = 0;
+      this.png.length = 0;
+      return this.png.marker = null;
+    };
+
     return ImageHeaders;
@@ -218,0 +284,0 @@

package.json

 {
   "name": "image-headers",
-  "version": "0.1.0",
+  "version": "0.2.0",
   "description": "Parse image headers from a stream without loading the entire image.",
-  "keywords": ["exif", "jpeg", "jpg", "gif"],
+  "keywords": ["exif", "jpeg", "jpg", "gif", "png", "streaming"],
   "repository": {
@@ -7,0 +7,0 @@ "type": "git",

No alert changes

Improved metrics

Total package byte prevSize

39270

6.18%

Lines of code

260

31.31%

No dependency changes