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waveform80 / picamera

A pure Python interface to the Raspberry Pi camera module
https://picamera.readthedocs.io/
BSD 3-Clause "New" or "Revised" License
1.57k stars 355 forks source link

JPEG thumbnails not working #234

Closed wsat closed 7 years ago

wsat commented 9 years ago

Hi,

I know this was an issue that was solved before but it seems it has popped up again. I am working with the python pi-timolo motion detection and capturing package: https://github.com/pageauc/pi-timolo To automatically create the thumbnails for a website, I am using the command (that's my only modification):

camera.capture(filename, format='jpeg', thumbnail=(200,100,35))

However, all pictures are captured with thumbnails being 64x48 pixels (below the output of EXIF.py):

Opening: motion/mo-cam1-1096.jpg File has JPEG thumbnail EXIF ApertureValue (Ratio): 6141/2000 EXIF BrightnessValue (Signed Ratio): 63/20 EXIF ColorSpace (Short): sRGB EXIF ComponentsConfiguration (Undefined): YCbCr EXIF DateTimeDigitized (ASCII): 2015:08:25 14:53:20 EXIF DateTimeOriginal (ASCII): 2015:08:25 14:53:20 EXIF ExifImageLength (Long): 1080 EXIF ExifImageWidth (Long): 1920 EXIF ExifVersion (Undefined): 0220 EXIF ExposureMode (Short): Auto Exposure EXIF ExposureProgram (Short): Aperture Priority EXIF ExposureTime (Ratio): 1349/1000000 EXIF FNumber (Ratio): 3623/1250 EXIF Flash (Short): Flash did not fire EXIF FlashPixVersion (Undefined): 0100 EXIF FocalLength (Ratio): 4497/1250 EXIF ISOSpeedRatings (Short): 100 EXIF InteroperabilityOffset (Long): 876 EXIF MakerNote (Undefined): [101, 118, 61, 45, 49, 32, 109, 108, 117, 120, 61, 45, 49, 32, 101, 120, 112, 61, 49, 51, ... ] EXIF MaxApertureValue (Ratio): 6141/2000 EXIF MeteringMode (Short): CenterWeightedAverage EXIF ShutterSpeedValue (Signed Ratio): 4766947/500000 EXIF WhiteBalance (Short): Auto Image DateTime (ASCII): 2015:08:25 14:53:20 Image ExifOffset (Long): 192 Image ImageLength (Long): 1080 Image ImageWidth (Long): 1920 Image Make (ASCII): RaspberryPi Image Model (ASCII): RP_OV5647 Image ResolutionUnit (Short): Pixels/Inch Image XResolution (Ratio): 72 Image YCbCrPositioning (Short): Centered Image YResolution (Ratio): 72 Interoperability InteroperabilityIndex (ASCII): R98 Thumbnail Compression (Short): JPEG (old-style) Thumbnail ImageLength (Long): 48 Thumbnail ImageWidth (Long): 64 Thumbnail JPEGInterchangeFormat (Long): 1012 Thumbnail JPEGInterchangeFormatLength (Long): 24576 Thumbnail ResolutionUnit (Short): Pixels/Inch Thumbnail XResolution (Ratio): 72 Thumbnail YResolution (Ratio): 72

waveform80 commented 8 years ago

Can you let me know if this is still an issue? I've tried it with the latest firmware (881) and if seems happy to me:

>>> from picamera import PiCamera
>>> camera.capture('foo.jpg', thumbnail=(400, 200, 35))

Then at the bash prompt (using a combination of tools from ImageMagick and ExifTool):

$ exiftool -b -ThumbnailImage foo.jpg > thumbnail.jpg
$ identify thumbnail.jpg
thumbnail.jpg JPEG 400x200 400x200+0+0 8-bit DirectClass 24.6KB 0.000u 0:00.000

One thing I'd check is exactly how you're reading the EXIF data; if you're using an old version of PIL, the EXIF support in there was thoroughly buggy (I vaguely recall playing with it in picroscopy and finding it just sent back the same values from the first file that was read) - I think later versions of Pillow (the now-supported fork) fixed that though.

waveform80 commented 7 years ago

Closing old issues; do re-open this if it's still a problem (though as noted above I suspect this is a problem with the way thumbnails are being read - I recently added some code to another ticket about extracting thumbnail data - I can dig that out if needed).