diff --git a/LibImage/CMakeLists.txt b/LibImage/CMakeLists.txt
index 33e1903e..00f300c3 100644
--- a/LibImage/CMakeLists.txt
+++ b/LibImage/CMakeLists.txt
@@ -5,6 +5,7 @@ project(libimage CXX)
 set(LIBIMAGE_SOURCES
 	Image.cpp
 	Netbpm.cpp
+	PNG.cpp
 )
 
 add_custom_target(libimage-headers
diff --git a/LibImage/Image.cpp b/LibImage/Image.cpp
index 0e0befa6..5c683e67 100644
--- a/LibImage/Image.cpp
+++ b/LibImage/Image.cpp
@@ -3,6 +3,7 @@
 
 #include <LibImage/Image.h>
 #include <LibImage/Netbpm.h>
+#include <LibImage/PNG.h>
 
 #include <fcntl.h>
 #include <stdlib.h>
@@ -55,6 +56,9 @@ namespace LibImage
 		if (probe_netbpm(image_data_span))
 			return TRY(load_netbpm(image_data_span));
 
+		if (probe_png(image_data_span))
+			return TRY(load_png(image_data_span));
+
 		fprintf(stderr, "unrecognized image format\n");
 		return BAN::Error::from_errno(ENOTSUP);
 	}
diff --git a/LibImage/PNG.cpp b/LibImage/PNG.cpp
new file mode 100644
index 00000000..ea1b1043
--- /dev/null
+++ b/LibImage/PNG.cpp
@@ -0,0 +1,668 @@
+#include <BAN/Debug.h>
+#include <BAN/Endianness.h>
+
+#include <LibImage/PNG.h>
+
+#include <ctype.h>
+
+namespace LibImage
+{
+
+	template<BAN::integral T>
+	struct PODNetworkEndian
+	{
+		T raw;
+		constexpr operator T() const { return BAN::network_endian_to_host(raw); }
+	};
+
+	enum class ColourType : uint8_t
+	{
+		Greyscale = 0,
+		Truecolour = 2,
+		IndexedColour = 3,
+		GreyscaleAlpha = 4,
+		TruecolourAlpha = 6,
+	};
+
+	enum class CompressionMethod : uint8_t
+	{
+		Deflate = 0,
+	};
+
+	enum class FilterMethod : uint8_t
+	{
+		Adaptive = 0,
+	};
+
+	enum class InterlaceMethod : uint8_t
+	{
+		NoInterlace = 0,
+		Adam7 = 1,
+	};
+
+	struct IHDR
+	{
+		PODNetworkEndian<uint32_t> width;
+		PODNetworkEndian<uint32_t> height;
+		uint8_t                    bit_depth;
+		ColourType                 colour_type;
+		CompressionMethod          compression_method;
+		FilterMethod               filter_method;
+		InterlaceMethod            interlace_method;
+	} __attribute__((packed));
+
+	struct PaletteEntry
+	{
+		uint8_t red;
+		uint8_t green;
+		uint8_t blue;
+	};
+
+	struct ZLibStream
+	{
+		uint8_t cm : 4;
+		uint8_t cinfo : 4;
+		uint8_t fcheck : 5;
+		uint8_t fdict : 1;
+		uint8_t flevel : 2;
+	};
+
+	struct PNGChunk
+	{
+		BAN::StringView name;
+		BAN::ConstByteSpan data;
+	};
+
+	class BinaryBuffer
+	{
+	public:
+		BinaryBuffer(BAN::Vector<BAN::ConstByteSpan> data)
+			: m_data(data)
+		{}
+
+		BAN::ErrorOr<uint16_t> peek_bits(uint8_t count)
+		{
+			ASSERT(count <= 16);
+
+			while (m_bit_buffer_len < count)
+			{
+				if (m_data.empty())
+					return BAN::Error::from_errno(ENODATA);
+				m_bit_buffer |= m_data[0][0] << m_bit_buffer_len;
+				m_bit_buffer_len += 8;
+				if (m_data[0].size() > 1)
+					m_data[0] = m_data[0].slice(1);
+				else
+					m_data.remove(0);
+			}
+
+			return m_bit_buffer & ((1 << count) - 1);
+		}
+
+		void remove_bits(uint8_t count)
+		{
+			ASSERT(count <= 16);
+			ASSERT(m_bit_buffer_len >= count);
+			m_bit_buffer_len -= count;
+			m_bit_buffer >>= count;
+		}
+
+		BAN::ErrorOr<uint16_t> get_bits(uint8_t count)
+		{
+			uint16_t result = TRY(peek_bits(count));
+			remove_bits(count);
+			return result;
+		}
+
+		void skip_to_byte_boundary()
+		{
+			m_bit_buffer >>= m_bit_buffer_len % 8;
+			m_bit_buffer_len -= m_bit_buffer_len % 8;
+		}
+
+	private:
+		BAN::Vector<BAN::ConstByteSpan> m_data;
+		uint32_t m_bit_buffer { 0 };
+		uint8_t m_bit_buffer_len { 0 };
+	};
+
+	constexpr uint16_t reverse_bits(uint16_t value, uint8_t count)
+	{
+		uint16_t reverse = 0;
+		for (uint8_t bit = 0; bit < count; bit++)
+			reverse |= ((value >> bit) & 1) << (count - bit - 1);
+		return reverse;
+	}
+
+	// https://www.rfc-editor.org/rfc/rfc1951
+	class HuffmanTree
+	{
+	public:
+		static constexpr uint8_t MAX_BITS = 15;
+
+		struct Leaf
+		{
+			uint16_t code;
+			uint8_t len;
+		};
+
+	public:
+		HuffmanTree() = default;
+		HuffmanTree(BAN::Vector<Leaf>&& leaves, uint8_t min_len, uint8_t max_len, uint8_t instant_max_bit)
+			: m_leaves(BAN::move(leaves))
+			, m_min_bits(min_len), m_max_bits(max_len)
+			, m_instant_max_bit(instant_max_bit)
+		{}
+
+		uint8_t min_bits() const { return m_min_bits; }
+		uint8_t max_bits() const { return m_max_bits; }
+		uint8_t instant_max_bit() const { return m_instant_max_bit; }
+		Leaf get_leaf(size_t index) const { return m_leaves[index]; }
+		bool empty() const { return m_leaves.empty(); }
+
+		static BAN::ErrorOr<HuffmanTree> create(const BAN::Vector<uint8_t>& bit_lengths)
+		{
+			uint16_t bl_count[MAX_BITS] {};
+			for (uint8_t bl : bit_lengths)
+				bl_count[bl]++;
+			bl_count[0] = 0;
+
+			uint8_t min_bits = MAX_BITS;
+			uint8_t max_bits = 0;
+			for (uint8_t bits = 0; bits <= MAX_BITS; bits++)
+			{
+				if (bit_lengths[bits] == 0)
+					continue;
+				min_bits = BAN::Math::min(min_bits, bits);
+				max_bits = BAN::Math::max(max_bits, bits);
+			}
+
+			uint8_t instant_max_bit = BAN::Math::min<uint8_t>(10, max_bits);
+			uint16_t instant_mask = (1 << instant_max_bit) - 1;
+
+			uint16_t code = 0;
+			uint16_t next_code[MAX_BITS + 1] {};
+			for (uint8_t bits = 1; bits <= max_bits; bits++)
+			{
+				code = (code + bl_count[bits - 1]) << 1;
+				next_code[bits] = code;
+			}
+
+			BAN::Vector<Leaf> leaves;
+			TRY(leaves.resize(1 << max_bits));
+
+			for (uint16_t n = 0; n < bit_lengths.size(); n++)
+			{
+				uint8_t bits = bit_lengths[n];
+				if (bits == 0)
+					continue;
+
+				uint16_t canonical = next_code[bits];
+				next_code[bits]++;
+
+				uint16_t reversed = reverse_bits(canonical, bits);
+				leaves[reversed] = Leaf { n, bits };
+
+				if (bits <= instant_max_bit)
+				{
+					uint16_t step = 1 << bits;
+					for (uint16_t spread = reversed + step; spread <= instant_mask; spread += step)
+						leaves[spread] = Leaf { n, bits };
+				}
+			}
+
+			return HuffmanTree(BAN::move(leaves), min_bits, max_bits, instant_max_bit);
+		}
+
+		static BAN::ErrorOr<HuffmanTree> fixed_tree()
+		{
+			BAN::Vector<uint8_t> bit_lengths;
+			TRY(bit_lengths.resize(288));
+			size_t i = 0;
+			for (; i <= 143; i++) bit_lengths[i] = 8;
+			for (; i <= 255; i++) bit_lengths[i] = 9;
+			for (; i <= 279; i++) bit_lengths[i] = 7;
+			for (; i <= 287; i++) bit_lengths[i] = 8;
+			return TRY(HuffmanTree::create(bit_lengths));
+		}
+
+	private:
+		BAN::Vector<Leaf> m_leaves;
+		uint8_t m_min_bits        { 0 };
+		uint8_t m_max_bits        { 0 };
+		uint8_t m_instant_max_bit { 0 };
+	};
+
+	class DeflateDecoder
+	{
+	public:
+		DeflateDecoder(BAN::Vector<BAN::ConstByteSpan> data)
+			: m_buffer(BinaryBuffer(BAN::move(data)))
+		{}
+
+		BAN::ErrorOr<BAN::ConstByteSpan> decode_stream()
+		{
+			while (!TRY(decode_block()))
+				continue;
+			return BAN::ConstByteSpan(m_decoded.span());
+		}
+
+	private:
+		BAN::ErrorOr<bool> decode_block()
+		{
+			bool bfinal = TRY(m_buffer.get_bits(1));
+			uint8_t btype = TRY(m_buffer.get_bits(2));
+
+			switch (btype)
+			{
+				case 0: TRY(decode_type0()); break;
+				case 1: TRY(decode_type1()); break;
+				case 2: TRY(decode_type2()); break;
+				default:
+					dwarnln("Deflate block has invalid method {}", btype);
+					return BAN::Error::from_errno(EINVAL);
+			}
+
+			return bfinal;
+		}
+
+		BAN::ErrorOr<void> decode_type0()
+		{
+			m_buffer.skip_to_byte_boundary();
+
+			uint16_t len = TRY(m_buffer.get_bits(16));
+			uint16_t nlen = TRY(m_buffer.get_bits(16));
+			if (len != 0xFFFF - nlen)
+			{
+				dwarnln("Deflate block uncompressed data length is invalid");
+				return BAN::Error::from_errno(EINVAL);
+			}
+
+			TRY(m_decoded.reserve(m_decoded.size() + len));
+			for (uint16_t i = 0; i < len; i++)
+				MUST(m_decoded.push_back(TRY(m_buffer.get_bits(8))));
+
+			return {};
+		}
+
+		BAN::ErrorOr<void> decode_type1()
+		{
+			TRY(inflate_block(TRY(HuffmanTree::fixed_tree()), HuffmanTree()));
+			return {};
+		}
+
+		BAN::ErrorOr<void> decode_type2()
+		{
+			static constexpr uint8_t code_length_order[] {
+				16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
+			};
+
+			const uint16_t hlit  = TRY(m_buffer.get_bits(5)) + 257;
+			const uint8_t  hdist = TRY(m_buffer.get_bits(5)) + 1;
+			const uint8_t  hclen = TRY(m_buffer.get_bits(4)) + 4;
+
+			HuffmanTree code_length_tree;
+			{
+				BAN::Vector<uint8_t> code_lengths;
+				TRY(code_lengths.resize(19, 0));
+				for (uint8_t i = 0; i < hclen; i++)
+					code_lengths[code_length_order[i]] = TRY(m_buffer.get_bits(3));
+				code_length_tree = TRY(HuffmanTree::create(code_lengths));
+			}
+
+			uint16_t last_symbol = 0;
+			BAN::Vector<uint8_t> bit_lengths;
+			TRY(bit_lengths.reserve(288 + 32));
+			while (bit_lengths.size() < hlit + hdist)
+			{
+				uint16_t symbol = TRY(read_symbol(code_length_tree));
+				uint8_t count = 0;
+
+				if (symbol <= 15)
+				{
+					count = 1;
+				}
+				else if (symbol == 16)
+				{
+					symbol = last_symbol;
+					count = TRY(m_buffer.get_bits(2)) + 3;
+				}
+				else if (symbol == 17)
+				{
+					symbol = 0;
+					count = TRY(m_buffer.get_bits(3)) + 3;
+				}
+				else if (symbol == 18)
+				{
+					symbol = 0;
+					count = TRY(m_buffer.get_bits(7)) + 11;
+				}
+
+				for (uint8_t i = 0; i < count; i++)
+					TRY(bit_lengths.push_back(symbol));
+				last_symbol = symbol;
+			}
+
+			TRY(bit_lengths.resize(hlit + 32, 0));
+
+			BAN::Vector<uint8_t> distance_lengths;
+			TRY(distance_lengths.resize(32));
+			for (uint8_t i = 0; i < 32; i++)
+				distance_lengths[i] = bit_lengths[hlit + i];
+
+			TRY(bit_lengths.resize(hlit));
+			TRY(bit_lengths.resize(288, 0));
+
+			TRY(inflate_block(TRY(HuffmanTree::create(bit_lengths)), TRY(HuffmanTree::create(distance_lengths))));
+			return {};
+		}
+
+		BAN::ErrorOr<void> inflate_block(const HuffmanTree& length_tree, const HuffmanTree& distance_tree)
+		{
+			static constexpr uint16_t length_base[] {
+				3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258
+			};
+			static constexpr uint8_t extra_length_bits[] {
+				0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0
+			};
+
+			static constexpr uint16_t distance_base[] {
+				1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145, 8193, 12289, 16385, 24577
+			};
+			static constexpr uint8_t extra_distance_bits[] {
+				0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13
+			};
+
+			uint16_t symbol;
+			while ((symbol = TRY(read_symbol(length_tree))) != 256)
+			{
+				if (symbol < 256)
+				{
+					TRY(m_decoded.push_back(symbol));
+					continue;
+				}
+
+				ASSERT(symbol <= 285);
+				symbol -= 257;
+
+				const uint16_t length = length_base[symbol] + TRY(m_buffer.get_bits(extra_length_bits[symbol]));
+
+				uint16_t distance_code;
+				if (distance_tree.empty())
+					distance_code = reverse_bits(TRY(m_buffer.get_bits(5)), 5);
+				else
+					distance_code = TRY(read_symbol(distance_tree));
+				ASSERT(distance_code <= 30);
+
+				const size_t distance = distance_base[distance_code] + TRY(m_buffer.get_bits(extra_distance_bits[distance_code]));
+
+				size_t offset = m_decoded.size() - distance;
+				for (size_t i = 0; i < length; i++)
+					TRY(m_decoded.push_back(m_decoded[offset + i]));
+			}
+
+			return {};
+		}
+
+		BAN::ErrorOr<uint16_t> read_symbol(const HuffmanTree& tree)
+		{
+			uint16_t compare = TRY(m_buffer.peek_bits(tree.max_bits()));
+			for (uint8_t bits = tree.instant_max_bit(); bits <= tree.max_bits(); bits++)
+			{
+				uint16_t mask = (1 << bits) - 1;
+				auto leaf = tree.get_leaf(compare & mask);
+
+				if (leaf.len <= bits)
+				{
+					m_buffer.remove_bits(leaf.len);
+					return leaf.code;
+				}
+			}
+			return BAN::Error::from_errno(EINVAL);
+		}
+
+	private:
+		BAN::Vector<uint8_t> m_decoded;
+		BinaryBuffer m_buffer;
+	};
+
+	BAN::ErrorOr<PNGChunk> read_and_take_chunk(BAN::ConstByteSpan& image_data)
+	{
+		if (image_data.size() < 12)
+		{
+			dwarnln("PNG stream does not contain any more chunks");
+			return BAN::Error::from_errno(EINVAL);
+		}
+
+		uint32_t length = image_data.as<const BAN::NetworkEndian<uint32_t>>();
+		image_data = image_data.slice(4);
+
+		if (image_data.size() < length + 8)
+		{
+			dwarnln("PNG stream does not contain any more chunks");
+			return BAN::Error::from_errno(EINVAL);
+		}
+
+		PNGChunk result;
+
+		result.name = BAN::StringView(image_data.as_span<const char>().data(), 4);
+		image_data = image_data.slice(4);
+
+		// skip chunk data
+		result.data = image_data.slice(0, length);
+		image_data = image_data.slice(length);
+
+		// FIXME: validate CRC
+		image_data = image_data.slice(4);
+
+		return result;
+	}
+
+	static bool validate_ihdr_colour_type_and_bit_depth(const IHDR& ihdr)
+	{
+		if (!BAN::Math::is_power_of_two(ihdr.bit_depth))
+			return false;
+		switch (ihdr.colour_type)
+		{
+			case ColourType::Greyscale:
+				if (ihdr.bit_depth < 1 || ihdr.bit_depth > 16)
+					return false;
+				return true;
+			case ColourType::Truecolour:
+				if (ihdr.bit_depth < 8 || ihdr.bit_depth > 16)
+					return false;
+				return true;
+			case ColourType::IndexedColour:
+				if (ihdr.bit_depth < 1 || ihdr.bit_depth > 8)
+					return false;
+				return true;
+			case ColourType::GreyscaleAlpha:
+				if (ihdr.bit_depth < 8 || ihdr.bit_depth > 16)
+					return false;
+				return true;
+			case ColourType::TruecolourAlpha:
+				if (ihdr.bit_depth < 8 || ihdr.bit_depth > 16)
+					return false;
+				return true;
+			default:
+				return false;
+		}
+	}
+
+	bool probe_png(BAN::ConstByteSpan image_data)
+	{
+		if (image_data.size() < 8)
+			return false;
+		uint64_t u64_signature = image_data.as<const uint64_t>();
+		return u64_signature == 0x0A1A0A0D474E5089;
+	}
+
+	BAN::ErrorOr<BAN::UniqPtr<Image>> load_png(BAN::ConstByteSpan image_data)
+	{
+		if (!probe_png(image_data))
+		{
+			dwarnln("Invalid PNG data");
+			return BAN::Error::from_errno(EINVAL);
+		}
+		image_data = image_data.slice(8);
+
+		auto ihdr_chunk = TRY(read_and_take_chunk(image_data));
+		if (ihdr_chunk.name != "IHDR")
+		{
+			dwarnln("PNG stream does not start with IHDR chunk");
+			return BAN::Error::from_errno(EINVAL);
+		}
+		if (ihdr_chunk.data.size() != sizeof(IHDR))
+		{
+			dwarnln("PNG stream has invalid IHDR chunk size: {}, expected {}", ihdr_chunk.data.size(), sizeof(IHDR));
+			return BAN::Error::from_errno(EINVAL);
+		}
+
+		const auto& ihdr = ihdr_chunk.data.as<const IHDR>();
+		if (ihdr.width == 0 || ihdr.height == 0 || ihdr.width > 0x7FFFFFFF || ihdr.height > 0x7FFFFFFF)
+		{
+			dwarnln("PNG IHDR has invalid size {}x{}", (uint32_t)ihdr.width, (uint32_t)ihdr.height);
+			return BAN::Error::from_errno(EINVAL);
+		}
+		if (!validate_ihdr_colour_type_and_bit_depth(ihdr))
+		{
+			dwarnln("PNG IHDR has invalid bit depth {} for colour type {}", ihdr.bit_depth, static_cast<uint8_t>(ihdr.colour_type));
+			return BAN::Error::from_errno(EINVAL);
+		}
+		if (ihdr.compression_method != CompressionMethod::Deflate)
+		{
+			dwarnln("PNG IHDR has invalid compression method {}", static_cast<uint8_t>(ihdr.compression_method));
+			return BAN::Error::from_errno(EINVAL);
+		}
+		if (ihdr.filter_method != FilterMethod::Adaptive)
+		{
+			dwarnln("PNG IHDR has invalid filter method {}", static_cast<uint8_t>(ihdr.filter_method));
+			return BAN::Error::from_errno(EINVAL);
+		}
+		if (ihdr.interlace_method != InterlaceMethod::NoInterlace && ihdr.interlace_method != InterlaceMethod::Adam7)
+		{
+			dwarnln("PNG IHDR has invalid interlace method {}", static_cast<uint8_t>(ihdr.interlace_method));
+			return BAN::Error::from_errno(EINVAL);
+		}
+
+		dprintln("Decoding {}x{} PNG image", (uint32_t)ihdr.width, (uint32_t)ihdr.height);
+		dprintln("  bit depth:          {}", ihdr.bit_depth);
+		dprintln("  colour type:        {}", static_cast<uint8_t>(ihdr.colour_type));
+		dprintln("  compression method: {}", static_cast<uint8_t>(ihdr.compression_method));
+		dprintln("  filter method:      {}", static_cast<uint8_t>(ihdr.filter_method));
+		dprintln("  interlace method:   {}", static_cast<uint8_t>(ihdr.interlace_method));
+
+		BAN::Vector<PaletteEntry> palette;
+		BAN::Vector<BAN::ConstByteSpan> zlib_stream;
+
+		while (true)
+		{
+			PNGChunk chunk;
+			if (auto ret = read_and_take_chunk(image_data); !ret.is_error())
+				chunk = ret.release_value();
+			else
+			{
+				dwarnln("PNG stream does not end with IEND chunk");
+				return BAN::Error::from_errno(EINVAL);
+			}
+
+			if (chunk.name == "IHDR"sv)
+			{
+				dwarnln("PNG stream has IDHR chunk defined multiple times");
+				return BAN::Error::from_errno(EINVAL);
+			}
+			else if (chunk.name == "PLTE"sv)
+			{
+				if (chunk.data.size() == 0 || chunk.data.size() % 3)
+				{
+					dwarnln("PNG PLTE has invalid data size {}", chunk.data.size());
+					return BAN::Error::from_errno(EINVAL);
+				}
+				if (!palette.empty())
+				{
+					dwarnln("PNG PLTE defined multiple times");
+					return BAN::Error::from_errno(EINVAL);
+				}
+				if (ihdr.colour_type != ColourType::IndexedColour && ihdr.colour_type != ColourType::Truecolour && ihdr.colour_type != ColourType::TruecolourAlpha)
+				{
+					dwarnln("PNG PLTE defined for colour type {} which does not use palette", static_cast<uint8_t>(ihdr.colour_type));
+					return BAN::Error::from_errno(EINVAL);
+				}
+				TRY(palette.resize(chunk.data.size() / 3));
+				for (size_t i = 0; i < palette.size(); i++)
+					palette[i] = chunk.data.as_span<const PaletteEntry>()[i];
+			}
+			else if (chunk.name == "IDAT"sv)
+			{
+				TRY(zlib_stream.push_back(chunk.data));
+			}
+			else if (chunk.name == "IEND"sv)
+			{
+				break;
+			}
+			else if (chunk.name == "tEXt"sv)
+			{
+				auto data_sv = BAN::StringView(chunk.data.as_span<const char>().data(), chunk.data.size());
+				if (auto idx = data_sv.find('\0'); !idx.has_value())
+					dwarnln("PNG tEXt chunk does not contain null-byte");
+				else
+				{
+					auto keyword = data_sv.substring(0, idx.value());
+					auto text = data_sv.substring(idx.value() + 1);
+					dprintln("'{}': '{}'", keyword, text);
+				}
+			}
+			else
+			{
+				bool ancillary = islower(chunk.name[0]);
+				if (!ancillary)
+				{
+					dwarnln("Unsupported critical chunk '{}'", chunk.name);
+					return BAN::Error::from_errno(ENOTSUP);
+				}
+				dwarnln("Skipping unsupported ancillary chunk '{}'", chunk.name);
+			}
+		}
+
+
+		{
+			if (zlib_stream.empty() || zlib_stream.front().size() < 2)
+			{
+				dwarnln("PNG does not have zlib stream");
+				return BAN::Error::from_errno(EINVAL);
+			}
+			if (zlib_stream[0].as<const BAN::BigEndian<uint16_t>>() % 31)
+			{
+				dwarnln("PNG zlib stream checksum failed");
+				return BAN::Error::from_errno(EINVAL);
+			}
+
+			auto zlib_header = zlib_stream[0].as<const ZLibStream>();
+			if (zlib_header.fdict)
+			{
+				dwarnln("PNG IDAT zlib stream has fdict set");
+				return BAN::Error::from_errno(EINVAL);
+			}
+			if (zlib_header.cm != 8)
+			{
+				dwarnln("PNG IDAT has invalid zlib compression method {}", (uint8_t)zlib_header.cm);
+				return BAN::Error::from_errno(EINVAL);
+			}
+			zlib_stream[0] = zlib_stream[0].slice(2);
+		}
+
+		uint64_t total_size = 0;
+		for (auto stream : zlib_stream)
+			total_size += stream.size();
+		dprintln("PNG has {} byte zlib stream", total_size);
+
+		DeflateDecoder decoder(BAN::move(zlib_stream));
+		auto decoded = TRY(decoder.decode_stream());
+
+		dprintln("  uncompressed size {}", decoded.size());
+		dprintln("  compression ratio {}", (double)decoded.size() / total_size);
+
+		return BAN::Error::from_errno(ENOTSUP);
+	}
+
+}
diff --git a/LibImage/include/LibImage/PNG.h b/LibImage/include/LibImage/PNG.h
new file mode 100644
index 00000000..cfd1a093
--- /dev/null
+++ b/LibImage/include/LibImage/PNG.h
@@ -0,0 +1,11 @@
+#include <BAN/ByteSpan.h>
+
+#include <LibImage/Image.h>
+
+namespace LibImage
+{
+
+	bool probe_png(BAN::ConstByteSpan);
+	BAN::ErrorOr<BAN::UniqPtr<Image>> load_png(BAN::ConstByteSpan);
+
+}