From c0829f16d548a5c9b7c080f49544abb554752b84 Mon Sep 17 00:00:00 2001
From: Liquid Cat <liquidcat@unknown>
Date: Wed, 31 Jul 2024 15:33:03 +0100
Subject: [PATCH 1/2] factor out numpy float mode handling

---
 imgcat/imgcat.py | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/imgcat/imgcat.py b/imgcat/imgcat.py
index e192667..2915b5b 100644
--- a/imgcat/imgcat.py
+++ b/imgcat/imgcat.py
@@ -98,14 +98,13 @@ def to_content_buf(data: Any) -> bytes:
         # numpy ndarray: convert to png
         import numpy
         im: 'numpy.ndarray' = data
+        if im.dtype.kind == 'f':
+            im = (im * 255).astype('uint8')
         if len(im.shape) == 2:
             mode = 'L'     # 8-bit pixels, grayscale
-            im = im.astype(sys.modules['numpy'].uint8)
         elif len(im.shape) == 3 and im.shape[2] in (1, 3, 4):
             # (H, W, C) format
             mode = None    # RGB/RGBA
-            if im.dtype.kind == 'f':
-                im = (im * 255).astype('uint8')
             if im.shape[2] == 1:
                 mode = 'L'  # 8-bit grayscale
                 im = numpy.squeeze(im, axis=2)
@@ -113,8 +112,6 @@ def to_content_buf(data: Any) -> bytes:
             # (C, H, W) format
             mode = None    # RGB/RGBA
             im = numpy.rollaxis(im, 0, 3)  # CHW -> HWC
-            if im.dtype.kind == 'f':
-                im = (im * 255).astype('uint8')
             if im.shape[2] == 1:
                 mode = 'L'  # 8-bit grayscale
                 im = numpy.squeeze(im, axis=2)

From 96c5a7c2e23330521b4c96c35f8f6dcc1bea0db2 Mon Sep 17 00:00:00 2001
From: Liquid Cat <liquidcat@unknown>
Date: Wed, 31 Jul 2024 15:53:40 +0100
Subject: [PATCH 2/2] Fix numpy mode to use full range

Old formula only used 255 at exactly 1.0, but used 0 for 1/255 of the
space. New formula uses both 0 and 255 (and every other number) for
exactly 1/256 of the space. If starting with a float between 0 and 1,
this is probably the intent.
---
 imgcat/imgcat.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/imgcat/imgcat.py b/imgcat/imgcat.py
index 2915b5b..9fb63fb 100644
--- a/imgcat/imgcat.py
+++ b/imgcat/imgcat.py
@@ -99,7 +99,8 @@ def to_content_buf(data: Any) -> bytes:
         import numpy
         im: 'numpy.ndarray' = data
         if im.dtype.kind == 'f':
-            im = (im * 255).astype('uint8')
+            # https://stackoverflow.com/a/66862750
+            im = (im * 256).clip(0, 255).astype('uint8')
         if len(im.shape) == 2:
             mode = 'L'     # 8-bit pixels, grayscale
         elif len(im.shape) == 3 and im.shape[2] in (1, 3, 4):