diff --git a/run_tests.py b/run_tests.py
new file mode 100644
index 0000000..03a358a
--- /dev/null
+++ b/run_tests.py
@@ -0,0 +1,30 @@
+from pathlib import Path
+
+import infiray_irg
+
+test_files = sorted(Path('test_pictures').glob('*.irg'))
+
+for f in test_files:
+    try:
+        coarse, fine, vis = infiray_irg.load(f.read_bytes(), print_debug_information=True)
+        print('\033[93m', f'{f.name:>20}', 'Coldest pixel:', fine.min(), 'C', 'Hottest pixel:', fine.max(), 'C', '\033[0m')
+    except Exception as e:
+        print(f'Error parsing {f}')
+        raise e
+
+print()
+print('Header diffs:')
+
+for offset, legend in {
+         0: 'magc hlen coars_len yres xres flg0 unk1 zero fine unk2 jpeg_len_ yres xres emissivit fine_off1 fine_off2 distance_',
+        64: '                    unit gain'}.items():
+    print(f'{" ":>20}', legend)
+    test_headers = {f: f.read_bytes()[offset:offset+64] for f in test_files}
+    header_idx_diffs = [len(set(header[i] for header in test_headers.values())) > 1 for i in range(64)]
+    for f, header in test_headers.items():
+        print(f'{str(f.name):>20}', ' '.join(
+            ''.join(
+                (f'\033[91m{header[i]:02x}' if header_idx_diffs[i] else f'\033[0m{header[i]:02x}')
+                for i in range(chunk, chunk+2))
+                    for chunk in range(0, 64, 2)
+            )+'\033[0m')
diff --git a/src/infiray_irg.py b/src/infiray_irg.py
index c6a583a..400febb 100644
--- a/src/infiray_irg.py
+++ b/src/infiray_irg.py
@@ -6,7 +6,7 @@ import io
 
 __version__ = "1.4.0"
 
-def load(data):
+def load(data, print_debug_information=False):
     def consume(n):
         nonlocal data
         out, data = data[:n], data[n:]
@@ -14,7 +14,18 @@ def load(data):
             raise ValueError(f'File is truncated, tried to read {n} bytes, but only {len(out)} bytes remain.')
         return out
 
-    header = consume(128)
+    header = consume(4)
+    _magic, header_len = struct.unpack('<HH', header)
+    header += consume(header_len - 4)
+
+    if print_debug_information:
+        import binascii
+        c200_reference_header = binascii.unhexlify('caac800000c000000001c00000008001000001c00001738300000001c0001c25000010a8290010a82900c4090000a00f000010270000000000001027000000000000000000000204000001000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000acca')
+        print('[infiray_irg debug] Header hex:', binascii.hexlify(header).decode()[:512])
+        print('[infiray_irg debug]  C200 diff:', ''.join(
+            (f'\033[0m{b:02x}' if a == b else f'\033[91m{b:02x}') for a, b in zip(header, c200_reference_header)
+            ) + '\033[0m')
+
     for model, match in {
             'c201': bytes([0xca, 0xac]),
             'other': bytes([0xba, 0xab]),
@@ -25,40 +36,48 @@ def load(data):
     else:
         raise ValueError(f'Header magic not found. Got header: {header[0]:02x} {header[1]:02x}')
 
-    _unk0, coarse_section_length, y_res, x_res,\
+    coarse_section_length, y_res, x_res,\
     flag0, _unk1, _zero1, fine_offset, _unk2, jpeg_length,\
-    y_res_2, x_res_2, _unk3, = struct.unpack('<HIHHHHHHHIHHI', header[2:34])
+    y_res_2, x_res_2, emissivity = struct.unpack('<IHHHHHHHIHHI', header[4:34])
+    emissivity /= 1e4
 
-    fine_temp_offset1, fine_temp_offset2, *rest, high_gain_mode_flag = struct.unpack('<11I', header[34:78])
+    # unit_flag indicates which temperature unit the UI was using. It does not seem to affect the image data in this
+    # file.
+    fine_temp_offset1, fine_temp_offset2, distance, *rest, unit_flag, high_gain_mode_flag = struct.unpack('<9IHHI', header[34:78])
+    distance /= 1e4
     
     if fine_temp_offset1 != fine_temp_offset2:
         warnings.warn(f'File lists two different zero offsets for the fine image data {fine_temp_offset1} and {fine_temp_offset2}. Resulting radiometric data might be offset. Please report this with an example file to code@jaseg.de.')
 
-    fine_temp_offset = fine_temp_offset1 / 10000
-
-#    import textwrap
-#    print(textwrap.dedent(f'''
-#        {_unk0=}, {coarse_section_length=}, {y_res=}, {x_res=},
-#        {flag0=}, {_unk1=}, {_zero1=}, {fine_offset=}, {_unk2=}, {jpeg_length=},
-#        {y_res_2=}, {x_res_2=}, {_unk3=}
-#        {fine_temp_offset1=} {fine_temp_offset1=} {rest=}, {high_gain_mode_flag=}'''))
+    if print_debug_information:
+        print('[infiray_irg debug] Matched model:', model)
+        import textwrap
+        print(textwrap.dedent(f'''
+            [infiray_irg debug] {header_len=}, {coarse_section_length=}, {y_res=}, {x_res=},
+            [infiray_irg debug] {flag0=}, {_unk1=}, {_zero1=}, {fine_offset=}, {_unk2=}, {jpeg_length=},
+            [infiray_irg debug] {y_res_2=}, {x_res_2=}, {emissivity=} {distance=}
+            [infiray_irg debug] {fine_temp_offset1=} {fine_temp_offset1=} {rest=}, {high_gain_mode_flag=} {unit_flag=}'''))
 
     if x_res*y_res != coarse_section_length:
         raise ValueError('Resolution mismatch in header')
         
     vis_jpg = None
+    coarse_img = np.frombuffer(consume(coarse_section_length), dtype=np.uint8).reshape((y_res, x_res))
+    fine_img = np.frombuffer(consume(x_res*y_res*2), dtype=np.uint16).reshape((y_res, x_res))
+
     if model == 'c201':
         if header[-2:] != bytes([0xac,0xca]):
             raise ValueError(f'Header end marker not found. Got header: {header[-2]:02x} {header[-1]:02x}')
-        coarse_img = np.frombuffer(consume(coarse_section_length), dtype=np.uint8).reshape((y_res, x_res))
-        fine_img = np.frombuffer(consume(x_res*y_res*2), dtype=np.uint16).reshape((y_res, x_res))
 
         if flag0 == 1: # Seen in Autel Robotics Evo II Dual 640T V3 file
-            fine_img = (fine_img / 64) - fine_temp_offset
+            fine_img = (fine_img / 64) - 25.0
 
         else: # C201 files
             # 1/16th Kelvin steps
-            fine_img = (fine_img / 16) - fine_temp_offset
+            fine_img = (fine_img / 16) - 273.15
+
+            # The offset for low gain mode images is a bit unclear. It seems all readings around room temperature and
+            # below in low gain mode are kind of garbage.
 
         if jpeg_length > 0:
             # I have seen a file from an Autel Robotics Evo II Dual 640T V3 that looks like a C201 file, but lacks the
@@ -66,20 +85,15 @@ def load(data):
             vis_jpg = Image.open(io.BytesIO(consume(jpeg_length)))
 
     elif model == 'other':
-        if header[-2:] != bytes([0xab,0xba]):
+        if header[-2:] != bytes([0xac,0xca]):
             raise ValueError(f'Header end marker not found. Got header: {header[-2]:02x} {header[-1]:02x}')
-        coarse_img = np.frombuffer(consume(coarse_section_length), dtype=np.uint8).reshape((y_res, x_res))
         # 0.1 Kelvin steps
-        fine_img = np.frombuffer(consume(x_res*y_res*2), dtype=np.uint16).reshape((y_res, x_res))
-        fine_img = fine_img / 10 - fine_temp_offset
+        fine_img = fine_img / 10 - 273.15
 
         vis_jpg = Image.open(io.BytesIO(data))
 
     else:
-        header += consume(128)
-        coarse_img = np.frombuffer(consume(coarse_section_length), dtype=np.uint8).reshape((y_res, x_res))
-        fine_img = np.frombuffer(consume(x_res*y_res*2), dtype=np.uint16).reshape((y_res, x_res))
-        fine_img = fine_img / 10 - fine_temp_offset
+        fine_img = fine_img / 10 - 273.2
 
         # In my example file, data now contains the JSON '{"roi":[]}' and no JPG. We ignore that.