CAllIBlock::ResizePicture

static function ResizePicture($arFile, $arResize)
{
	if($arFile["tmp_name"] == '')
		return $arFile;

	if(array_key_exists("error", $arFile) && $arFile["error"] !== 0)
		return GetMessage("IBLOCK_BAD_FILE_ERROR");

	$file = $arFile["tmp_name"];

	if(!file_exists($file) && !is_file($file))
		return GetMessage("IBLOCK_BAD_FILE_NOT_FOUND");

	$width = (int)$arResize["WIDTH"];
	$height = (int)$arResize["HEIGHT"];

	if($width <= 0 && $height <= 0)
		return $arFile;

	$image = new Image($file);
	$imageInfo = $image->getInfo(false);
	if (empty($imageInfo))
	{
		return GetMessage("IBLOCK_BAD_FILE_NOT_PICTURE");
	}
	$orig = [
		0 => $imageInfo->getWidth(),
		1 => $imageInfo->getHeight(),
		2 => $imageInfo->getFormat(),
		3 => $imageInfo->getAttributes(),
		"mime" => $imageInfo->getMime(),
	];

	$width_orig = $orig[0];
	$height_orig = $orig[1];

	$orientation = 0;
	$exifData = [];
	$image_type = $orig[2];
	if($image_type == Image::FORMAT_JPEG)
	{
		$exifData = $image->getExifData();
		if (isset($exifData['Orientation']))
		{
			$orientation = $exifData['Orientation'];
			if ($orientation >= 5 && $orientation <= 8)
			{
				$width_orig = $orig[1];
				$height_orig = $orig[0];
			}
		}
	}

	if(($width > 0 && $orig[0] > $width) || ($height > 0 && $orig[1] > $height))
	{
		if($arFile["COPY_FILE"] == "Y")
		{
			$new_file = CTempFile::GetFileName(basename($file));
			CheckDirPath($new_file);
			$arFile["copy"] = true;

			if(copy($file, $new_file))
				$file = $new_file;
			else
				return GetMessage("IBLOCK_BAD_FILE_NOT_FOUND");
		}

		if($width <= 0)
			$width = $width_orig;

		if($height <= 0)
			$height = $height_orig;

		$height_new = $height_orig;
		if($width_orig > $width)
			$height_new = $width * $height_orig  / $width_orig;

		if($height_new > $height)
			$width = $height * $width_orig / $height_orig;
		else
			$height = $height_new;

		$image_type = $orig[2];
		if ($image_type == Image::FORMAT_JPEG)
		{
			$image = imagecreatefromjpeg($file);
			if ($image === false)
			{
				ini_set('gd.jpeg_ignore_warning', 1);
				$image = imagecreatefromjpeg($file);
			}

			if ($orientation > 1)
			{
				if ($orientation == 7 || $orientation == 8)
					$image = imagerotate($image, 90, null);
				elseif ($orientation == 3 || $orientation == 4)
					$image = imagerotate($image, 180, null);
				elseif ($orientation == 5 || $orientation == 6)
					$image = imagerotate($image, 270, null);

				if (
					$orientation == 2 || $orientation == 7
					|| $orientation == 4 || $orientation == 5
				)
				{
					$engine = new ImageGd();
					$engine->setResource($image);
					$engine->flipHorizontal();
				}
			}
		}
		elseif ($image_type == Image::FORMAT_GIF)
		{
			$image = imagecreatefromgif($file);
		}
		elseif ($image_type == Image::FORMAT_PNG)
		{
			$image = imagecreatefrompng($file);
		}
		elseif ($image_type == Image::FORMAT_WEBP)
		{
			$image = imagecreatefromwebp($file);
		}
		else
		{
			return GetMessage("IBLOCK_ERR_BAD_FILE_UNSUPPORTED");
		}

		$image_p = imagecreatetruecolor($width, $height);
		if($image_type == Image::FORMAT_JPEG)
		{
			if($arResize["METHOD"] === "resample")
				imagecopyresampled($image_p, $image, 0, 0, 0, 0, $width, $height, $width_orig, $height_orig);
			else
				imagecopyresized($image_p, $image, 0, 0, 0, 0, $width, $height, $width_orig, $height_orig);

			if($arResize["COMPRESSION"] > 0)
				imagejpeg($image_p, $file, $arResize["COMPRESSION"]);
			else
				imagejpeg($image_p, $file);
		}
		elseif($image_type == Image::FORMAT_GIF && function_exists("imagegif"))
		{
			imagetruecolortopalette($image_p, true, imagecolorstotal($image));
			imagepalettecopy($image_p, $image);

			//Save transparency for GIFs
			$transparentColor = imagecolortransparent($image);
			if($transparentColor >= 0 && $transparentColor < imagecolorstotal($image))
			{
				$transparentColor = imagecolortransparent($image_p, $transparentColor);
				imagefilledrectangle($image_p, 0, 0, $width, $height, $transparentColor);
			}

			if($arResize["METHOD"] === "resample")
				imagecopyresampled($image_p, $image, 0, 0, 0, 0, $width, $height, $width_orig, $height_orig);
			else
				imagecopyresized($image_p, $image, 0, 0, 0, 0, $width, $height, $width_orig, $height_orig);
			imagegif($image_p, $file);
		}
		else
		{
			//Save transparency for PNG
			$transparentColor = imagecolorallocatealpha($image_p, 0, 0, 0, 127);
			imagefilledrectangle($image_p, 0, 0, $width, $height, $transparentColor);
			$transparentColor = imagecolortransparent($image_p, $transparentColor);

			imagealphablending($image_p, false);
			if($arResize["METHOD"] === "resample")
				imagecopyresampled($image_p, $image, 0, 0, 0, 0, $width, $height, $width_orig, $height_orig);
			else
				imagecopyresized($image_p, $image, 0, 0, 0, 0, $width, $height, $width_orig, $height_orig);

			imagesavealpha($image_p, true);
			imagepng($image_p, $file);
		}

		imagedestroy($image);
		imagedestroy($image_p);

		$arFile["size"] = filesize($file);
		$arFile["tmp_name"] = $file;
		return $arFile;
	}
	else
	{
		return $arFile;
	}
}