diff --git a/core/docs/toif.md b/core/docs/toif.md
index 1b7499e8f..bd7493421 100644
--- a/core/docs/toif.md
+++ b/core/docs/toif.md
@@ -17,8 +17,8 @@ All multibyte integer values are little endian!
 
 TOI currently supports 2 variants:
 
-* `f`: full-color, file extension `.toif`
-* `g`: gray-scale, file extension `.toig`
+* `f`: full-color
+* `g`: gray-scale
 
 ### Full-color
 
@@ -55,5 +55,4 @@ zdata = zdata[2:-4] # strip header and checksum
 
 ## Tools
 
-* [png2toi](../tools/png2toi) - tool for converting PNG into TOI format
-* [toi2png](../tools/toi2png) - tool for converting TOI into PNG
+* [toif_convert](../tools/toif_convert) - tool for converting PNGs into TOI format and back
diff --git a/core/src/apps/management/res/small-arrow.toig b/core/src/apps/management/res/small-arrow.toif
similarity index 100%
rename from core/src/apps/management/res/small-arrow.toig
rename to core/src/apps/management/res/small-arrow.toif
diff --git a/core/src/trezor/res/cancel.toig b/core/src/trezor/res/cancel.toif
similarity index 100%
rename from core/src/trezor/res/cancel.toig
rename to core/src/trezor/res/cancel.toif
diff --git a/core/src/trezor/res/check.toig b/core/src/trezor/res/check.toif
similarity index 100%
rename from core/src/trezor/res/check.toig
rename to core/src/trezor/res/check.toif
diff --git a/core/src/trezor/res/click.toig b/core/src/trezor/res/click.toif
similarity index 100%
rename from core/src/trezor/res/click.toig
rename to core/src/trezor/res/click.toif
diff --git a/core/src/trezor/res/confirm.toig b/core/src/trezor/res/confirm.toif
similarity index 100%
rename from core/src/trezor/res/confirm.toig
rename to core/src/trezor/res/confirm.toif
diff --git a/core/src/trezor/res/header_icons/cog.toig b/core/src/trezor/res/header_icons/cog.toif
similarity index 100%
rename from core/src/trezor/res/header_icons/cog.toig
rename to core/src/trezor/res/header_icons/cog.toif
diff --git a/core/src/trezor/res/header_icons/nocopy.toig b/core/src/trezor/res/header_icons/nocopy.toif
similarity index 100%
rename from core/src/trezor/res/header_icons/nocopy.toig
rename to core/src/trezor/res/header_icons/nocopy.toif
diff --git a/core/src/trezor/res/header_icons/receive.toig b/core/src/trezor/res/header_icons/receive.toif
similarity index 100%
rename from core/src/trezor/res/header_icons/receive.toig
rename to core/src/trezor/res/header_icons/receive.toif
diff --git a/core/src/trezor/res/header_icons/recovery.toig b/core/src/trezor/res/header_icons/recovery.toif
similarity index 100%
rename from core/src/trezor/res/header_icons/recovery.toig
rename to core/src/trezor/res/header_icons/recovery.toif
diff --git a/core/src/trezor/res/header_icons/reset.toig b/core/src/trezor/res/header_icons/reset.toif
similarity index 100%
rename from core/src/trezor/res/header_icons/reset.toig
rename to core/src/trezor/res/header_icons/reset.toif
diff --git a/core/src/trezor/res/header_icons/send.toig b/core/src/trezor/res/header_icons/send.toif
similarity index 100%
rename from core/src/trezor/res/header_icons/send.toig
rename to core/src/trezor/res/header_icons/send.toif
diff --git a/core/src/trezor/res/header_icons/wipe.toig b/core/src/trezor/res/header_icons/wipe.toif
similarity index 100%
rename from core/src/trezor/res/header_icons/wipe.toig
rename to core/src/trezor/res/header_icons/wipe.toif
diff --git a/core/src/trezor/res/header_icons/wrong.toig b/core/src/trezor/res/header_icons/wrong.toif
similarity index 100%
rename from core/src/trezor/res/header_icons/wrong.toig
rename to core/src/trezor/res/header_icons/wrong.toif
diff --git a/core/src/trezor/res/left.toig b/core/src/trezor/res/left.toif
similarity index 100%
rename from core/src/trezor/res/left.toig
rename to core/src/trezor/res/left.toif
diff --git a/core/src/trezor/res/lock.toig b/core/src/trezor/res/lock.toif
similarity index 100%
rename from core/src/trezor/res/lock.toig
rename to core/src/trezor/res/lock.toif
diff --git a/core/src/trezor/res/pin_close.toig b/core/src/trezor/res/pin_close.toif
similarity index 100%
rename from core/src/trezor/res/pin_close.toig
rename to core/src/trezor/res/pin_close.toif
diff --git a/core/src/trezor/res/recovery.toig b/core/src/trezor/res/recovery.toif
similarity index 100%
rename from core/src/trezor/res/recovery.toig
rename to core/src/trezor/res/recovery.toif
diff --git a/core/src/trezor/res/space.toig b/core/src/trezor/res/space.toif
similarity index 100%
rename from core/src/trezor/res/space.toig
rename to core/src/trezor/res/space.toif
diff --git a/core/src/trezor/res/swipe.toig b/core/src/trezor/res/swipe.toif
similarity index 100%
rename from core/src/trezor/res/swipe.toig
rename to core/src/trezor/res/swipe.toif
diff --git a/core/src/trezor/ui/style.py b/core/src/trezor/ui/style.py
index 38e73efac..420819f79 100644
--- a/core/src/trezor/ui/style.py
+++ b/core/src/trezor/ui/style.py
@@ -47,22 +47,22 @@ BG = BLACK
 FG = WHITE
 
 # icons
-ICON_RESET = "trezor/res/header_icons/reset.toig"
-ICON_WIPE = "trezor/res/header_icons/wipe.toig"
-ICON_RECOVERY = "trezor/res/header_icons/recovery.toig"
-ICON_NOCOPY = "trezor/res/header_icons/nocopy.toig"
-ICON_WRONG = "trezor/res/header_icons/wrong.toig"
-ICON_CONFIG = "trezor/res/header_icons/cog.toig"
-ICON_RECEIVE = "trezor/res/header_icons/receive.toig"
-ICON_SEND = "trezor/res/header_icons/send.toig"
+ICON_RESET = "trezor/res/header_icons/reset.toif"
+ICON_WIPE = "trezor/res/header_icons/wipe.toif"
+ICON_RECOVERY = "trezor/res/header_icons/recovery.toif"
+ICON_NOCOPY = "trezor/res/header_icons/nocopy.toif"
+ICON_WRONG = "trezor/res/header_icons/wrong.toif"
+ICON_CONFIG = "trezor/res/header_icons/cog.toif"
+ICON_RECEIVE = "trezor/res/header_icons/receive.toif"
+ICON_SEND = "trezor/res/header_icons/send.toif"
 
 ICON_DEFAULT = ICON_CONFIG
 
-ICON_CANCEL = "trezor/res/cancel.toig"
-ICON_CONFIRM = "trezor/res/confirm.toig"
-ICON_LOCK = "trezor/res/lock.toig"
-ICON_CLICK = "trezor/res/click.toig"
-ICON_BACK = "trezor/res/left.toig"
-ICON_SWIPE = "trezor/res/swipe.toig"
-ICON_CHECK = "trezor/res/check.toig"
-ICON_SPACE = "trezor/res/space.toig"
+ICON_CANCEL = "trezor/res/cancel.toif"
+ICON_CONFIRM = "trezor/res/confirm.toif"
+ICON_LOCK = "trezor/res/lock.toif"
+ICON_CLICK = "trezor/res/click.toif"
+ICON_BACK = "trezor/res/left.toif"
+ICON_SWIPE = "trezor/res/swipe.toif"
+ICON_CHECK = "trezor/res/check.toif"
+ICON_SPACE = "trezor/res/space.toif"
diff --git a/core/tools/png2toi b/core/tools/png2toi
deleted file mode 100755
index e9be14170..000000000
--- a/core/tools/png2toi
+++ /dev/null
@@ -1,119 +0,0 @@
-#!/usr/bin/env python3
-from PIL import Image
-import sys
-import struct
-import zlib
-from os.path import basename
-
-
-def process_rgb(w, h, pix):
-    data = bytes()
-    for j in range(h):
-        for i in range(w):
-            r, g, b = pix[i, j]
-            c = ((r & 0xF8) << 8) | ((g & 0xFC) << 3) | ((b & 0xF8) >> 3)
-            data += struct.pack(">H", c)
-    return data
-
-
-def process_grayscale(w, h, pix):
-    data = bytes()
-    for j in range(h):
-        for i in range(w // 2):
-            l1, l2 = pix[i * 2, j], pix[i * 2 + 1, j]
-            c = (l1 & 0xF0) | (l2 >> 4)
-            data += struct.pack(">B", c)
-    return data
-
-
-def process_image(ifn, savefiles=False):
-    im = Image.open(ifn)
-    w, h = im.size
-    print("Opened %s ... %d x %d @ %s" % (ifn, w, h, im.mode))
-
-    if im.mode == "RGB":
-        print("Detected RGB mode")
-    elif im.mode == "L":
-        if w % 2 > 0:
-            print("PNG file must have width divisible by 2")
-            return 3
-        print("Detected GRAYSCALE mode")
-    else:
-        print("Unknown mode:", im.mode)
-        return 4
-
-    pix = im.load()
-
-    bname = basename(ifn[:-4])
-    ofn_h = "%s.h" % bname
-    ofn_py = "%s.py" % bname
-
-    if im.mode == "RGB":
-        ofn = "%s.toif" % bname
-        pixeldata = process_rgb(w, h, pix)
-    else:
-        ofn = "%s.toig" % bname
-        pixeldata = process_grayscale(w, h, pix)
-    z = zlib.compressobj(level=9, wbits=10)
-    zdata = z.compress(pixeldata) + z.flush()
-    zdata = zdata[2:-4]  # strip header and checksum
-
-    data = b""
-    if im.mode == "RGB":
-        data += b"TOIf"
-    else:
-        data += b"TOIg"
-    data += struct.pack("<HH", w, h)
-    data += struct.pack("<I", len(zdata))
-    data += zdata
-
-    if savefiles:
-        with open(ofn, "wb") as f:
-            f.write(data)
-            print("Written %s ... %d bytes" % (ofn, len(data)))
-        with open(ofn_py, "wb") as f:
-            f.write(("%s = %s\n" % (bname, data)).encode())
-            print("Written %s ... %d bytes" % (ofn_py, len(data)))
-        with open(ofn_h, "wt") as f:
-            f.write("// clang-format off\n")
-            f.write("static const uint8_t toi_%s[] = {\n" % bname)
-            f.write("    // magic\n")
-            if im.mode == "RGB":
-                f.write("    'T', 'O', 'I', 'f',\n")
-            else:
-                f.write("    'T', 'O', 'I', 'g',\n")
-            f.write("    // width (16-bit), height (16-bit)\n")
-            f.write(
-                "    0x%02x, 0x%02x, 0x%02x, 0x%02x,\n"
-                % (w & 0xFF, w >> 8, h & 0xFF, h >> 8)
-            )
-            l = len(zdata)
-            f.write("    // compressed data length (32-bit)\n")
-            f.write(
-                "    0x%02x, 0x%02x, 0x%02x, 0x%02x,\n"
-                % (l & 0xFF, (l >> 8) & 0xFF, (l >> 16) & 0xFF, l >> 24)
-            )
-            f.write("    // compressed data\n")
-            f.write("   ")
-            for b in zdata:
-                f.write(" 0x%02x," % b)
-            f.write("\n};\n")
-            print("Written %s ... done" % ofn_py)
-
-    return data
-
-
-def main():
-    if len(sys.argv) < 2:
-        print("Usage png2toi image.png")
-        return 1
-
-    ifn = sys.argv[1]
-    if not ifn.endswith(".png"):
-        print("Must provide PNG file")
-        return 2
-
-    process_image(ifn, savefiles=True)
-
-
-main()
diff --git a/core/tools/toi2png b/core/tools/toi2png
deleted file mode 100755
index d6d17521d..000000000
--- a/core/tools/toi2png
+++ /dev/null
@@ -1,92 +0,0 @@
-#!/usr/bin/env python3
-from PIL import Image
-import sys
-import struct
-import zlib
-
-
-def process_rgb(w, h, data):
-    pix = bytearray(w * h * 3)
-    for i in range(w * h):
-        c = (data[i * 2] << 8) + data[i * 2 + 1]
-        pix[i * 3 + 0] = (c & 0xF800) >> 8
-        pix[i * 3 + 1] = (c & 0x07C0) >> 3
-        pix[i * 3 + 2] = (c & 0x001F) << 3
-    return bytes(pix)
-
-
-def process_grayscale(w, h, data):
-    pix = bytearray(w * h)
-    for i in range(w * h // 2):
-        pix[i * 2 + 0] = data[i] & 0xF0
-        pix[i * 2 + 1] = (data[i] & 0x0F) << 4
-    return bytes(pix)
-
-
-def process_image(ifn, ofn):
-
-    data = open(ifn, "rb").read()
-
-    if ifn.endswith(".toif"):
-        if data[:4] != b"TOIf":
-            print("Unknown TOIF header")
-            return 1
-    elif ifn.endswith(".toig"):
-        if data[:4] != b"TOIg":
-            print("Unknown TOIG header")
-            return 2
-    else:
-        print("Unsupported format")
-        return 3
-    if ofn is None:
-        ofn = "%s.png" % ifn[:-5]
-
-    w, h = struct.unpack("<HH", data[4:8])
-
-    print("Opened %s ... %d x %d" % (ifn, w, h))
-
-    l = struct.unpack("<I", data[8:12])[0]
-    data = data[12:]
-    if len(data) != l:
-        print("Compressed data length mismatch (%d vs %d)" % (len(data), l))
-        return 4
-    data = zlib.decompress(data, -10)
-
-    if ifn.endswith(".toif"):
-        if len(data) != w * h * 2:
-            print(
-                "Uncompressed data length mismatch (%d vs %d)" % (len(data), w * h * 2)
-            )
-            return 5
-        pix = process_rgb(w, h, data)
-        img = Image.frombuffer("RGB", (w, h), pix, "raw", "RGB", 0, 1)
-        img.save(ofn)
-        print("Written %s ..." % ofn)
-
-    if ifn.endswith(".toig"):
-        if len(data) != w * h // 2:
-            print(
-                "Uncompressed data length mismatch (%d vs %d)" % (len(data), w * h // 2)
-            )
-            return 6
-        pix = process_grayscale(w, h, data)
-        img = Image.frombuffer("L", (w, h), pix, "raw", "L", 0, 1)
-        img.save(ofn)
-        print("Written %s ..." % ofn)
-
-
-def main():
-    if len(sys.argv) < 2:
-        print("Usage: toi2png image.toi[fg] [output]")
-        return 1
-
-    ifn = sys.argv[1]
-    if not ifn.endswith(".toif") and not ifn.endswith(".toig"):
-        print("Must provide TOIF/TOIG file")
-        return 2
-
-    ofn = sys.argv[2] if len(sys.argv) > 2 else None
-    process_image(ifn, ofn)
-
-
-main()
diff --git a/core/tools/toif_convert b/core/tools/toif_convert
new file mode 100755
index 000000000..824d325df
--- /dev/null
+++ b/core/tools/toif_convert
@@ -0,0 +1,152 @@
+#!/usr/bin/env python3
+from PIL import Image
+import io
+import sys
+import struct
+import zlib
+from os.path import basename
+
+
+def png2toif(input_data):
+
+    def process_rgb(w, h, pix):
+        data = bytes()
+        for j in range(h):
+            for i in range(w):
+                r, g, b = pix[i, j]
+                c = ((r & 0xF8) << 8) | ((g & 0xFC) << 3) | ((b & 0xF8) >> 3)
+                data += struct.pack(">H", c)
+        return data
+
+    def process_grayscale(w, h, pix):
+        data = bytes()
+        for j in range(h):
+            for i in range(w // 2):
+                l1, l2 = pix[i * 2, j], pix[i * 2 + 1, j]
+                c = (l1 & 0xF0) | (l2 >> 4)
+                data += struct.pack(">B", c)
+        return data
+
+    im = Image.open(io.BytesIO(input_data))
+    w, h = im.size
+    if im.mode not in ["RGB", "L"]:
+        raise ValueError("Unknown mode:", im.mode)
+    if im.mode == "L":
+        if w % 2 > 0:
+            raise ValueError("PNG file must have width divisible by 2")
+
+    pix = im.load()
+    if im.mode == "RGB":
+        pixeldata = process_rgb(w, h, pix)
+    else:
+        pixeldata = process_grayscale(w, h, pix)
+    z = zlib.compressobj(level=9, wbits=10)
+    zdata = z.compress(pixeldata) + z.flush()
+    zdata = zdata[2:-4]  # strip header and checksum
+
+    data = b""
+    if im.mode == "RGB":
+        data += b"TOIf"
+    else:
+        data += b"TOIg"
+    data += struct.pack("<HH", w, h)
+    data += struct.pack("<I", len(zdata))
+    data += zdata
+
+    return data
+
+    """
+    with open(ofn_py, "wb") as f:
+        f.write(("%s = %s\n" % (bname, data)).encode())
+    with open(ofn_h, "wt") as f:
+        f.write("// clang-format off\n")
+        f.write("static const uint8_t toi_%s[] = {\n" % bname)
+        f.write("    // magic\n")
+        if im.mode == "RGB":
+            f.write("    'T', 'O', 'I', 'f',\n")
+        else:
+            f.write("    'T', 'O', 'I', 'g',\n")
+        f.write("    // width (16-bit), height (16-bit)\n")
+        f.write(
+            "    0x%02x, 0x%02x, 0x%02x, 0x%02x,\n"
+            % (w & 0xFF, w >> 8, h & 0xFF, h >> 8)
+        )
+        l = len(zdata)
+        f.write("    // compressed data length (32-bit)\n")
+        f.write(
+            "    0x%02x, 0x%02x, 0x%02x, 0x%02x,\n"
+            % (l & 0xFF, (l >> 8) & 0xFF, (l >> 16) & 0xFF, l >> 24)
+        )
+        f.write("    // compressed data\n")
+        f.write("   ")
+        for b in zdata:
+            f.write(" 0x%02x," % b)
+        f.write("\n};\n")
+    """
+
+
+
+def toif2png(data):
+
+    def process_rgb(w, h, data):
+        pix = bytearray(w * h * 3)
+        for i in range(w * h):
+            c = (data[i * 2] << 8) + data[i * 2 + 1]
+            pix[i * 3 + 0] = (c & 0xF800) >> 8
+            pix[i * 3 + 1] = (c & 0x07C0) >> 3
+            pix[i * 3 + 2] = (c & 0x001F) << 3
+        return bytes(pix)
+
+
+    def process_grayscale(w, h, data):
+        pix = bytearray(w * h)
+        for i in range(w * h // 2):
+            pix[i * 2 + 0] = data[i] & 0xF0
+            pix[i * 2 + 1] = (data[i] & 0x0F) << 4
+        return bytes(pix)
+
+    if data[:4] != b"TOIf" and data[:4] != b"TOIg":
+        raise ValueError("Unknown TOIF header")
+    format = data[:4].decode().lower()
+    w, h = struct.unpack("<HH", data[4:8])
+    l = struct.unpack("<I", data[8:12])[0]
+    data = data[12:]
+    if len(data) != l:
+        raise ValueError("Compressed data length mismatch (%d vs %d)" % (len(data), l))
+    data = zlib.decompress(data, -10)
+
+    if format == "toif":
+        if len(data) != w * h * 2:
+            raise ValueError("Uncompressed data length mismatch (%d vs %d)" % (len(data), w * h * 2))
+        pix = process_rgb(w, h, data)
+        img = Image.frombuffer("RGB", (w, h), pix, "raw", "RGB", 0, 1)
+        ret = io.BytesIO()
+        img.save(ret, format="PNG")
+        return ret.getvalue()
+
+    if format == "toig":
+        if len(data) != w * h // 2:
+            raise ValueError("Uncompressed data length mismatch (%d vs %d)" % (len(data), w * h // 2))
+        pix = process_grayscale(w, h, data)
+        img = Image.frombuffer("L", (w, h), pix, "raw", "L", 0, 1)
+        ret = io.BytesIO()
+        img.save(ret, format="PNG")
+        return ret.getvalue()
+
+
+def main():
+    if len(sys.argv) < 2:
+        print("Usage: toi_convert [input.png|input.toif] [output.toif|output.png]")
+        return 1
+    ifn, ofn = sys.argv[1], sys.argv[2]
+    if ifn.endswith(".png") and ofn.endswith(".toif"):
+        open(ofn, "wb").write(png2toif(open(ifn, "rb").read()))
+    elif ifn.endswith(".toif") and ofn.endswith(".png"):
+        open(ofn, "wb").write(toif2png(open(ifn, "rb").read()))
+    else:
+        print("Must provide a valid combination of PNG/TOIF or TOIF/PNG files")
+        return 2
+
+
+if __name__ == "__main__":
+    main()