ImageStat module calculates global statistics for an image, or
for a region of an image.
- class PIL.ImageStat.Stat(image_or_list, mask=None)¶
Calculate statistics for the given image. If a mask is included, only the regions covered by that mask are included in the statistics. You can also pass in a previously calculated histogram.
A PIL image, or a precalculated histogram.
For a PIL image, calculations rely on the
histogram()method. The pixel counts are grouped into 256 bins, even if the image has more than 8 bits per channel. So
Fmode images have a maximum
rmsof 255, and cannot have an
extremamaximum of more than 255.
mask – An optional mask.
Min/max values for each band in the image.
This relies on the
histogram()method, and simply returns the low and high bins used. This is correct for images with 8 bits per channel, but fails for other modes such as
F. Instead, use
getextrema()to return per-band extrema for the image. This is more correct and efficient because, for non-8-bit modes, the histogram method uses
getextrema()to determine the bins used.
Total number of pixels for each band in the image.
Sum of all pixels for each band in the image.
Squared sum of all pixels for each band in the image.
Average (arithmetic mean) pixel level for each band in the image.
Median pixel level for each band in the image.
RMS (root-mean-square) for each band in the image.
Variance for each band in the image.
Standard deviation for each band in the image.