imageio.read seems to misbehave on a 1-bit grayscale with alpha format: a fully transparent image encoded with 1 bit per value, where all the bits are transparent. The BufferedImage parsed by imageio is displayed fully black and does seem to be missing transparency.
output of file on the file:
PNG image data, 150 x 200, 1-bit grayscale, non-interlaced
output of identify -verbose on the file:
Format: PNG (Portable Network Graphics)
Mime type: image/png
Class: DirectClass
Geometry: 150x200+0+0
Resolution: 1x1
Print size: 150x200
Units: Undefined
Type: Bilevel
Base type: Bilevel
Endianess: Undefined
Colorspace: Gray
Depth: 8/1-bit
Channel depth:
gray: 1-bit
alpha: 1-bit
Channel statistics:
Pixels: 30000
Gray:
min: 0 (0)
max: 0 (0)
mean: 0 (0)
standard deviation: 0 (0)
kurtosis: 0
skewness: 0
entropy: -nan
Alpha:
min: 0 (0)
max: 0 (0)
mean: 0 (0)
standard deviation: 0 (0)
kurtosis: 0
skewness: 0
entropy: -nan
Alpha: graya(0,0) #00000000
Colors: 1
Histogram:
30000: ( 0, 0, 0, 0) #00000000 graya(0,0)
Rendering intent: Undefined
Gamma: 0.45455
Chromaticity:
red primary: (0.64,0.33)
green primary: (0.3,0.6)
blue primary: (0.15,0.06)
white point: (0.3127,0.329)
Background color: graya(255,1)
Border color: graya(223,1)
Matte color: graya(189,1)
Transparent color: graya(0,0)
Interlace: None
Intensity: Undefined
Compose: Over
Page geometry: 150x200+0+0
Dispose: Undefined
Iterations: 0
Compression: Zip
Orientation: Undefined
Properties:
Creator: Adobe After Effects
date:create: 2018-02-14T21:28:25+01:00
date:modify: 2018-02-14T21:28:25+01:00
png:bKGD: chunk was found (see Background color, above)
png:cHRM: chunk was found (see Chromaticity, above)
png:gAMA: gamma=0.45455 (See Gamma, above)
png:IHDR.bit-depth-orig: 1
png:IHDR.bit_depth: 1
png:IHDR.color-type-orig: 0
png:IHDR.color_type: 0 (Grayscale)
png:IHDR.interlace_method: 0 (Not interlaced)
png:IHDR.width,height: 150, 200
png:pHYs: x_res=1, y_res=1, units=0
png:text: 3 tEXt/zTXt/iTXt chunks were found
png:tIME: 2018-02-09T14:30:39Z
png:tRNS: chunk was found
signature: 9a413b131ecf0ccfb02a837ddb33766d8604cc00da7937b79bd363b53c8d7d86
Artifacts:
filename: out/snow_00000.png
verbose: true
Tainted: False
Filesize: 349B
Number pixels: 30K
Pixels per second: 0B
User time: 0.000u
Elapsed time: 0:01.000
Version: ImageMagick 6.9.0-3 Q16 x86_64 2015-02-15 http://www.imagemagick.org
We probably need a more robust image decoding library for the AWT backend. The workaround for now is to re-encode the image in a more classic RGB with alpha, instead of using the more compact 1 bit encoding.
It happens on the call to .close() on the AWT Clip object. This seems due to the default OpenJDK implementation of sampled sound with PulseAudio (/etc/java-8-openjdk/sound.properties):
javax.sound.sampled.Clip=org.classpath.icedtea.pulseaudio.PulseAudioMixerProvider
javax.sound.sampled.Port=org.classpath.icedtea.pulseaudio.PulseAudioMixerProvider
javax.sound.sampled.SourceDataLine=org.classpath.icedtea.pulseaudio.PulseAudioMixerProvider
javax.sound.sampled.TargetDataLine=org.classpath.icedtea.pulseaudio.PulseAudioMixerProvider
Replace the above in the same configuration file by:
javax.sound.sampled.Clip=com.sun.media.sound.DirectAudioDeviceProvider
javax.sound.sampled.Port=com.sun.media.sound.PortMixerProvider
javax.sound.sampled.SourceDataLine=com.sun.media.sound.DirectAudioDeviceProvider
javax.sound.sampled.TargetDataLine=com.sun.media.sound.DirectAudioDeviceProvider
This should fix the problem.