Legacy ImageMagick Discussions Archive

source photo: http://user-avatar.u.qiniudn.com/avatar ... b3ab33.png
I want convert the photo's format is jpg
Command:
mogrify -auto-orient -format jpg -thumbnail 200x200> -strip -quality 85 abnormal.png

But the result is wrong

Your input PNG image is corrupted. It has an "iDOT" chunk which is not defined in the PNG spec, at least one iDAT chunk is truncated, and the IEND chunk is missing.

• pngcheck -v 51922d*
  File: 51922de0fc1692de9201385f7db3ab33.png (84202 bytes)
  chunk IHDR at offset 0x0000c, length 13
  200 x 200 image, 32-bit RGB+alpha, non-interlaced
  chunk sRGB at offset 0x00025, length 1
  rendering intent = perceptual
  chunk iDOT at offset 0x00032, length 28: illegal (unless recently approved) unknown, public chunk
  ERRORS DETECTED in 51922de0fc1692de9201385f7db3ab33.png

• identify -verbose 51922d*.png
  q16identify: Expected 8192 bytes; found 7473 bytes `51922de0fc1692de9201385f7db3ab33.png' @ warning/png.c/MagickPNGWarningHandler/1831.

• pngcrush -n -v 51922d*.png
  Opening file 51922de0fc1692de9201385f7db3ab33.png for length measurement
  Allocating read structure
  Allocating read_info, end_info structures
  Reading IHDR chunk, length = 13.
  Reading sRGB chunk, length = 1.
  Reading iDOT chunk, length = 28.
  Reading IDAT chunk, length = 16384.
  Reading IDAT chunk, length = 16384.
  Reading IDAT chunk, length = 16384.
  Reading IDAT chunk, length = 2847.
  Reading IDAT chunk, length = 16384.
  Reading IDAT chunk, length = 16384.
  While measuring IDATs in 51922de0fc1692de9201385f7db3ab33.png pngcrush caught libpng error:
  Read Error

glennrp wrote:Your input PNG image is corrupted. It has an "iDOT" chunk which is not defined in the PNG spec, at least one iDAT chunk is truncated, and the IEND chunk is missing.

• pngcheck -v 51922d*
  File: 51922de0fc1692de9201385f7db3ab33.png (84202 bytes)
  chunk IHDR at offset 0x0000c, length 13
  200 x 200 image, 32-bit RGB+alpha, non-interlaced
  chunk sRGB at offset 0x00025, length 1
  rendering intent = perceptual
  chunk iDOT at offset 0x00032, length 28: illegal (unless recently approved) unknown, public chunk
  ERRORS DETECTED in 51922de0fc1692de9201385f7db3ab33.png

• identify -verbose 51922d*.png
  q16identify: Expected 8192 bytes; found 7473 bytes `51922de0fc1692de9201385f7db3ab33.png' @ warning/png.c/MagickPNGWarningHandler/1831.

• pngcrush -n -v 51922d*.png
  Opening file 51922de0fc1692de9201385f7db3ab33.png for length measurement
  Allocating read structure
  Allocating read_info, end_info structures
  Reading IHDR chunk, length = 13.
  Reading sRGB chunk, length = 1.
  Reading iDOT chunk, length = 28.
  Reading IDAT chunk, length = 16384.
  Reading IDAT chunk, length = 16384.
  Reading IDAT chunk, length = 16384.
  Reading IDAT chunk, length = 2847.
  Reading IDAT chunk, length = 16384.
  Reading IDAT chunk, length = 16384.
  While measuring IDATs in 51922de0fc1692de9201385f7db3ab33.png pngcrush caught libpng error:
  Read Error

So,how to solve?
As users , the picture i can see then it should be handled

Sequential decoders like ImageMagick, pngcrush, etc., can't read it.
You could display the useable part of the image using a progressive reader
(firefox or chrome will do it) and then take a screen shot.

glennrp wrote:Sequential decoders like ImageMagick, pngcrush, etc., can't read it.
You could display the useable part of the image using a progressive reader
(firefox or chrome will do it) and then take a screen shot.

OK.thank you very much

Would it not be best to fix the code/tool that generates your png images, so they conform to the standard?