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IDProjectCategoryView StatusLast Update
0000506fileGeneralpublic2024-03-01 03:31
ReporterMartin Assigned Tochristos  
PrioritynormalSeverityfeatureReproducibilityalways
Status resolvedResolutionfixed 
PlatformLinuxOSArch LinuxOS VersionN/A
Product Version5.45 
Fixed in VersionHEAD 
Summary0000506: Detect PNGs with APNG extension as such
Descriptionfile currently does not have any magic values for APNG PNG's, resulting it to label everything as PNG.

Example image is provided on wikipedia.

https://en.wikipedia.org/wiki/APNG

APNG has been supported by all major browsers for years and as of recently is being standardized in the new PNG spec as a core feature.

See initial changelog fragment in https://www.w3.org/TR/png-3/#changes-20031110 and scroll *UP* to see the subsequent ones.

And the Explainer document for the Third Edition PNG spec https://github.com/w3c/PNG-spec/blob/main/Third_Edition_Explainer.md
Steps To Reproduceimagemagick's identify seems to have the same issue as file (unsure which magic file it uses, perhaps the one from file), but at least it can be forced as APNG to show the frame count if any.

Using the wikipedia page image:

[0] % file ball.png
ball.png: PNG image data, 100 x 100, 8-bit/color RGBA, non-interlaced

[0] % identify ball.png
ball.png PNG 100x100 100x100+0+0 8-bit sRGB 61968B 0.000u 0:00.000

[0] % identify apng:ball.png
apng:ball.png=>ball.png[0] APNG 100x100 100x100+0+0 8-bit sRGB 53670B 0.000u 0:00.000
apng:ball.png=>ball.png[1] APNG 39x63 100x100+30+36 8-bit sRGB 0.000u 0:00.000
apng:ball.png=>ball.png[2] APNG 39x56 100x100+30+40 8-bit sRGB 0.000u 0:00.000
apng:ball.png=>ball.png[3] APNG 39x65 100x100+30+34 8-bit sRGB 0.000u 0:00.000
apng:ball.png=>ball.png[4] APNG 39x77 100x100+30+22 8-bit sRGB 0.000u 0:00.000
apng:ball.png=>ball.png[5] APNG 39x81 100x100+30+18 8-bit sRGB 0.000u 0:00.000
apng:ball.png=>ball.png[6] APNG 39x83 100x100+30+16 8-bit sRGB 0.000u 0:00.000
apng:ball.png=>ball.png[7] APNG 39x85 100x100+30+14 8-bit sRGB 0.000u 0:00.000
apng:ball.png=>ball.png[8] APNG 39x91 100x100+30+8 8-bit sRGB 0.000u 0:00.000
apng:ball.png=>ball.png[9] APNG 39x97 100x100+30+2 8-bit sRGB 0.000u 0:00.000
apng:ball.png=>ball.png[10] APNG 39x37 100x100+30+2 8-bit sRGB 0.000u 0:00.000
apng:ball.png=>ball.png[11] APNG 39x36 100x100+30+2 8-bit sRGB 0.000u 0:00.000
apng:ball.png=>ball.png[12] APNG 39x37 100x100+30+2 8-bit sRGB 0.000u 0:00.000
apng:ball.png=>ball.png[13] APNG 39x97 100x100+30+2 8-bit sRGB 0.000u 0:00.000
apng:ball.png=>ball.png[14] APNG 39x95 100x100+30+4 8-bit sRGB 0.000u 0:00.000
apng:ball.png=>ball.png[15] APNG 39x91 100x100+30+8 8-bit sRGB 0.000u 0:00.000
apng:ball.png=>ball.png[16] APNG 39x89 100x100+30+10 8-bit sRGB 0.000u 0:00.000
apng:ball.png=>ball.png[17] APNG 39x85 100x100+30+14 8-bit sRGB 0.000u 0:00.000
apng:ball.png=>ball.png[18] APNG 39x79 100x100+30+20 8-bit sRGB 0.000u 0:00.000
apng:ball.png=>ball.png[19] APNG 39x75 100x100+30+24 8-bit sRGB 0.000u 0:00.000
TagsNo tags attached.

Activities

christos

2024-03-01 03:31

manager   ~0004015

Fixed, thanks!

Issue History

Date Modified Username Field Change
2024-02-26 12:54 Martin New Issue
2024-03-01 03:31 christos Assigned To => christos
2024-03-01 03:31 christos Status new => assigned
2024-03-01 03:31 christos Status assigned => resolved
2024-03-01 03:31 christos Resolution open => fixed
2024-03-01 03:31 christos Fixed in Version => HEAD
2024-03-01 03:31 christos Note Added: 0004015