Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Optimize ImageStat.Stat.extrema #7593

Merged
merged 5 commits into from
Dec 6, 2023
Merged

Optimize ImageStat.Stat.extrema #7593

Changes from 4 commits
Commits
Show all changes
5 commits
Select commit Hold shift + click to select a range
1b8f9d3
Optimize ImageStat.Stat._getextrema function
florath Dec 1, 2023
7762dd3
Fixed spacing in _getextrema method
florath Dec 1, 2023
96fe0a1
Merge branch 'main' into ImageStat_getextrema_opt
radarhere Dec 2, 2023
ac47b75
Update src/PIL/ImageStat.py
florath Dec 4, 2023
ed03954
Merge branch 'main' into ImageStat_getextrema_opt
florath Dec 5, 2023
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
15 changes: 9 additions & 6 deletions src/PIL/ImageStat.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -53,17 +53,20 @@ def _getextrema(self):
"""Get min/max values for each band in the image"""

def minmax(histogram):
n = 255
x = 0
res_min, res_max = 255, 0
for i in range(256):
if histogram[i]:
n = min(n, i)
x = max(x, i)
return n, x # returns (255, 0) if there's no data in the histogram
res_min = i
break
for i in range(255, -1, -1):
if histogram[i]:
res_max = i
break
return res_min, res_max

v = []
for i in range(0, len(self.h), 256):
v.append(minmax(self.h[i:]))
v.append(minmax(self.h[i : i + 256]))
return v
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

you can also use list comprehension

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

My idea was to have a minimal patch set.

If you want, we could go with

return [minmax(self.h[i:i+256]) for i in range(0, len(self.h), 256)]

My tests showed that from the performance point of view the two solutions are mostly the same. But if my other patch gets accepted #7599 the list comprehension might be the way to go to have the same style.

What do you think?

Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

#7597 has actually just been merged to use list comprehension here. Would you like to resolve the conflict?

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Done.


def _getcount(self):
Expand Down