<?php // Simple .ICO parsing. The ICO format is insanely complex and this may // fail to correctly handle some technically valid files, but it works // on the majority I've found. // // jimIcon was written in 2013 by Jim Paris <jim@jtan.com> and is // released under the terms of the CC0: // // To the extent possible under law, the author(s) have dedicated all // copyright and related and neighboring rights to this software to // the public domain worldwide. This software is distributed without // any arranty. // // You may have received a copy of the CC0 Public Domain Dedication // along with this software. If not, see // http://creativecommons.org/publicdomain/zero/1.0/ class jimIcon { // Get an image color from a string function get_color($str, $img) { $b = ord($str[0]); $g = ord($str[1]); $r = ord($str[2]); if (strlen($str) > 3) { $a = 127 - (ord($str[3]) / 2); if ($a != 0 && $a != 127) $this->had_alpha = 1; } else { $a = 0; } if ($a != 127) $this->all_transaprent = 0; return imagecolorallocatealpha($img, $r, $g, $b, $a); } // Given a string with the contents of an .ICO, // return a GD image of the icon, or false on error. function fromiconstring($ico) { $this->error = "(unknown error)"; $this->had_alpha = 0; // Read header if (strlen($ico) < 6) { $this->error = "too short"; return false; } $h = unpack("vzero/vtype/vnum", $ico); // Must be ICO format with at least one image if ($h["zero"] != 0 || $h["type"] != 1 || $h["num"] == 0) { // See if we can just parse it with GD directly // if it's not ICO format; maybe it was a mislabeled // PNG or something. $i = @imagecreatefromstring($ico); if ($i) { imagesavealpha($i, true); return $i; } $this->error = "not ICO or other image"; return false; } // Read directory entries to find the biggest image $most_pixels = 0; for ($i = 0; $i < $h["num"]; $i++) { $entry = substr($ico, 6 + 16 * $i, 16); if (!$entry || strlen($entry) < 16) continue; $e = unpack("Cwidth/" . "Cheight/" . "Ccolors/" . "Czero/" . "vplanes/" . "vbpp/" . "Vsize/" . "Voffset/", $entry); if ($e["width"] == 0) $e["width"] = 256; if ($e["height"] == 0) $e["height"] = 256; if ($e["zero"] != 0) { $this->error = "nonzero reserved field"; return false; } $pixels = $e["width"] * $e["height"]; if ($pixels > $most_pixels) { $most_pixels = $pixels; $most = $e; } } if ($most_pixels == 0) { $this->error = "no pixels"; return false; } $e = $most; // Extract image data $data = substr($ico, $e["offset"], $e["size"]); if (!$data || strlen($data) != $e["size"]) { $this->error = "bad image data"; return false; } // See if we can parse it (might be PNG format here) $i = @imagecreatefromstring($data); if ($i) { imagesavealpha($img, true); return $i; } // Must be a BMP. Parse it ourselves. $img = imagecreatetruecolor($e["width"], $e["height"]); imagesavealpha($img, true); $bg = imagecolorallocatealpha($img, 255, 0, 0, 127); imagefill($img, 0, 0, $bg); // Skip over the BITMAPCOREHEADER or BITMAPINFOHEADER; // we'll just assume the palette and pixel data follow // in the most obvious format as described by the icon // directory entry. $bitmapinfo = unpack("Vsize", $data); if ($bitmapinfo["size"] == 40) { $info = unpack("Vsize/" . "Vwidth/" . "Vheight/" . "vplanes/" . "vbpp/" . "Vcompress/" . "Vsize/" . "Vxres/" . "Vyres/" . "Vpalcolors/" . "Vimpcolors/", $data); if ($e["bpp"] == 0) { $e["bpp"] = $info["bpp"]; } } $data = substr($data, $bitmapinfo["size"]); $height = $e["height"]; $width = $e["width"]; $bpp = $e["bpp"]; // For indexed images, we only support 1, 4, or 8 BPP switch ($bpp) { case 1: case 4: case 8: $indexed = 1; break; case 24: case 32: $indexed = 0; break; default: $this->error = "bad BPP $bpp"; return false; } $offset = 0; if ($indexed) { $palette = array(); $this->all_transparent = 1; for ($i = 0; $i < (1 << $bpp); $i++) { $entry = substr($data, $i * 4, 4); $palette[$i] = $this->get_color($entry, $img); } $offset = $i * 4; // Hack for some icons: if everything was transparent, // discard alpha channel. if ($this->all_transparent) { for ($i = 0; $i < (1 << $bpp); $i++) { $palette[$i] &= 0xffffff; } } } // Assume image data follows in bottom-up order. // First the "XOR" image if ((strlen($data) - $offset) < ($bpp * $height * $width / 8)) { $this->error = "short data"; return false; } $XOR = array(); for ($y = $height - 1; $y >= 0; $y--) { $x = 0; while ($x < $width) { if (!$indexed) { $bytes = $bpp / 8; $entry = substr($data, $offset, $bytes); $pixel = $this->get_color($entry, $img); $XOR[$y][$x] = $pixel; $x++; $offset += $bytes; } elseif ($bpp == 1) { $p = ord($data[$offset]); for ($b = 0x80; $b > 0; $b >>= 1) { if ($p & $b) { $pixel = $palette[1]; } else { $pixel = $palette[0]; } $XOR[$y][$x] = $pixel; $x++; } $offset++; } elseif ($bpp == 4) { $p = ord($data[$offset]); $pixel1 = $palette[$p >> 4]; $pixel2 = $palette[$p & 0x0f]; $XOR[$y][$x] = $pixel1; $XOR[$y][$x+1] = $pixel2; $x += 2; $offset++; } elseif ($bpp == 8) { $pixel = $palette[ord($data[$offset])]; $XOR[$y][$x] = $pixel; $x += 1; $offset++; } else { $this->error = "bad BPP"; return false; } } // End of row padding while ($offset & 3) $offset++; } // Now the "AND" image, which is 1 bit per pixel. Ignore // if some of our image data already had alpha values, // or if there isn't enough data left. if ($this->had_alpha || ((strlen($data) - $offset) < ($height * $width / 8))) { // Just return what we've got for ($y = 0; $y < $height; $y++) { for ($x = 0; $x < $width; $x++) { imagesetpixel($img, $x, $y, $XOR[$y][$x]); } } return $img; } // Mask what we have with the "AND" image for ($y = $height - 1; $y >= 0; $y--) { $x = 0; while ($x < $width) { for ($b = 0x80; $b > 0 && $x < $width; $b >>= 1) { if (!(ord($data[$offset]) & $b)) { imagesetpixel($img, $x, $y, $XOR[$y][$x]); } $x++; } $offset++; } // End of row padding while ($offset & 3) $offset++; } return $img; } } ?>