it takes 4 seconds for 4K image HEIC to decodie

[ByteYIFFF]

Is there any way to speed up decodin. e.g.:heif_decode_image
2021-10-20 112837.zip
g

[farindk]

For me 0,8s on a 4770k CPU including writing two images to JPEG:

$ time heif-convert 2021-10-20\ 112837.heic out.jpg
File contains 1 images
Written to out.jpg
Auxiliary image written to out-urn:com:apple:photo:2020:aux:hdrgainmap.jpg

real	0m0,843s

[homm]

It should be at least two times faster (mobile i5-8279U). See #551 and #555.

In [1]: from HeifImagePlugin import Image, pyheif

In [2]: data = open('./2021-10-20 112837.heic', 'rb').read()

In [3]: %%time
   ...: heif_file = pyheif.read(data, apply_transformations=False)
   ...: image = Image.frombytes(
   ...:     heif_file.mode, heif_file.size, heif_file.data,
   ...:     "raw", heif_file.mode, heif_file.stride)
   ...:
CPU times: user 709 ms, sys: 79.5 ms, total: 788 ms
Wall time: 279 ms

[ByteYIFFF]

the problem still exists。And heif_decode_image runs slowly. Is it related to my libheif version? Are you using the master branch?

[ByteYIFFF]

It should be at least two times faster (mobile i5-8279U). See #551 and #555.

In [1]: from HeifImagePlugin import Image, pyheif                                                                               

In [2]: data = open('./2021-10-20 112837.heic', 'rb').read()                                                                    

In [3]: %%time 
   ...: heif_file = pyheif.read(data, apply_transformations=False) 
   ...: image = Image.frombytes( 
   ...:     heif_file.mode, heif_file.size, heif_file.data, 
   ...:     "raw", heif_file.mode, heif_file.stride) 
   ...:                                                                                                                         
CPU times: user 709 ms, sys: 79.5 ms, total: 788 ms
Wall time: 279 ms

my cpu is i7-8700K. my version is v.1.12.0.
@homm

[ByteYIFFF]

hi.guys~
i know why it takes too much time for decoding.Because I choose to acquire RGB data.if i acquire yuv, the decoding will be qiuck.

[ByteYIFFF]

对于我在 4770k CPU 上的 0.8 秒，包括将两个图像写入 JPEG：

$ time heif-convert 2021-10-20\ 112837.heic out.jpg
File contains 1 images
Written to out.jpg
Auxiliary image written to out-urn:com:apple:photo:2020:aux:hdrgainmap.jpg

real	0m0,843s

please，try to transform HEIC to a PNG picture. i guess that it will need more time to decode. @farindk

[homm]

So it takes 4 seconds for 4K image to encode in PNG, right?

[ByteYIFFF]

So it takes 4 seconds for 4K image to encode in PNG, right?

"i know why it takes too much time for decoding.Because I choose to acquire RGB data.if i acquire yuv, the decoding will be qiuck."------this is my guess.

in my computer, for a 4K heic, it takes 2second to run this code (heif_decode_image(handle, &img, heif_colorspace_RGB, heif_chroma_interleaved_RGBA, nullptr) @homm

[ByteYIFFF]

所以 4K 图像在 PNG 中编码需要 4 秒，对吗？

in fact, when i decode image in YCBCR, the time not reduce. @homm

[freemedom]

Why are heic images about 10 times slower than jpg? (generate thumbnails) Because heic doesn't have hardware acceleration?