Legacy ImageMagick Discussions Archive

Source photop:
http://kakapart.qiniudn.com/2013-4-11-1 ... 143390.jpg
I want to change the photo's width and height.but thumbnail invalid
My command:
convert error.jpg -auto-orient -thumbnail 200x200> -strip -quality 85.0 +repage /tmp/imgview228325518

But this command apply others photo is ok

The file you posted is BMP and not JPG and has a alpha channel that may not be formed correctly. It is pure black (transparent), but when displaying the BMP file it shows as opaque.

This works for me by removing the alpha channel. Your BMP file has no EXIF data, so -auto-orient will do not good, nor -strip in this case, since there is nothing to strip.
Also your command ends in /tmp/imgview228325518, which specifies no file format.

fmw42 wrote:The file you posted is BMP and not JPG and has a alpha channel that may not be formed correctly. It is pure black (transparent), but when displaying the BMP file it shows as opaque.

This works for me by removing the alpha channel. Your BMP file has no EXIF data, so -auto-orient will do not good, nor -strip in this case, since there is nothing to strip.

Code: Select all

convert error.bmp -alpha off -thumbnail "200x200>" -quality 85 tmp.jpg

Also your command ends in /tmp/imgview228325518, which specifies no file format.

Thanks for your reply,could you tell me how to know a alpha channel that may not be formed correctly.
Which command or software you use ,and the information

Short summary:

Type: GrayscaleAlpha
Base type: GrayscaleAlpha
Endianess: Undefined
Colorspace: Gray
Depth: 8-bit
Channel depth:
gray: 8-bit
alpha: 1-bit
Channel statistics:
Pixels: 31500
Gray:
min: 2 (0.00784314)
max: 255 (1)
mean: 231.142 (0.906439)
standard deviation: 49.8097 (0.195332)
kurtosis: 3.35404
skewness: -2.10644
Alpha:
min: 0 (0)
max: 0 (0)
mean: 0 (0)
standard deviation: 0 (0)
kurtosis: 0
skewness: 0


Full Summary: Also

fmw42 wrote:

Code: Select all

identify -verbose error.bmp

Short summary:

Type: GrayscaleAlpha
Base type: GrayscaleAlpha
Endianess: Undefined
Colorspace: Gray
Depth: 8-bit
Channel depth:
gray: 8-bit
alpha: 1-bit
Channel statistics:
Pixels: 31500
Gray:
min: 2 (0.00784314)
max: 255 (1)
mean: 231.142 (0.906439)
standard deviation: 49.8097 (0.195332)
kurtosis: 3.35404
skewness: -2.10644
Alpha:
min: 0 (0)
max: 0 (0)
mean: 0 (0)
standard deviation: 0 (0)
kurtosis: 0
skewness: 0


Full Summary:

Code: Select all

Image: error.bmp
  Format: BMP (Microsoft Windows bitmap image)
  Class: DirectClass
  Geometry: 210x150+0+0
  Resolution: 37.8x37.8
  Print size: 5.55556x3.96825
  Units: PixelsPerCentimeter
  Type: GrayscaleAlpha
  Base type: GrayscaleAlpha
  Endianess: Undefined
  Colorspace: Gray
  Depth: 8-bit
  Channel depth:
    gray: 8-bit
    alpha: 1-bit
  Channel statistics:
    Pixels: 31500
    Gray:
      min: 2 (0.00784314)
      max: 255 (1)
      mean: 231.142 (0.906439)
      standard deviation: 49.8097 (0.195332)
      kurtosis: 3.35404
      skewness: -2.10644
    Alpha:
      min: 0 (0)
      max: 0 (0)
      mean: 0 (0)
      standard deviation: 0 (0)
      kurtosis: 0
      skewness: 0
  Alpha: graya(255,0)   #FFFFFF00
  Colors: 123
  Histogram:
         1: (  2,  2,  2,  0) #02020200 graya(2,0)
         1: (  4,  4,  4,  0) #04040400 graya(4,0)
         1: (  7,  7,  7,  0) #07070700 graya(7,0)
         4: ( 11, 11, 11,  0) #0B0B0B00 graya(11,0)
         2: ( 12, 12, 12,  0) #0C0C0C00 graya(12,0)
         3: ( 19, 19, 19,  0) #13131300 graya(19,0)
         4: ( 20, 20, 20,  0) #14141400 graya(20,0)
        10: ( 22, 22, 22,  0) #16161600 graya(22,0)
         3: ( 25, 25, 25,  0) #19191900 graya(25,0)
         9: ( 27, 27, 27,  0) #1B1B1B00 graya(27,0)
        11: ( 28, 28, 28,  0) #1C1C1C00 graya(28,0)
        10: ( 31, 31, 31,  0) #1F1F1F00 graya(31,0)
        11: ( 32, 32, 32,  0) #20202000 graya(32,0)
        10: ( 35, 35, 35,  0) #23232300 graya(35,0)
        11: ( 36, 36, 36,  0) #24242400 graya(36,0)
        22: ( 39, 39, 39,  0) #27272700 graya(39,0)
        92: ( 40, 40, 40,  0) #28282800 graya(40,0)
         4: ( 42, 42, 42,  0) #2A2A2A00 graya(42,0)
         3: ( 45, 45, 45,  0) #2D2D2D00 graya(45,0)
         2: ( 46, 46, 46,  0) #2E2E2E00 graya(46,0)
         3: ( 49, 49, 49,  0) #31313100 graya(49,0)
         5: ( 50, 50, 50,  0) #32323200 graya(50,0)
         1: ( 53, 53, 53,  0) #35353500 graya(53,0)
         2: ( 54, 54, 54,  0) #36363600 graya(54,0)
         2: ( 56, 56, 56,  0) #38383800 graya(56,0)
         1: ( 59, 59, 59,  0) #3B3B3B00 graya(59,0)
         5: ( 63, 63, 63,  0) #3F3F3F00 graya(63,0)
        32: ( 64, 64, 64,  0) #40404000 graya(64,0)
        79: ( 67, 67, 67,  0) #43434300 graya(67,0)
         6: ( 68, 68, 68,  0) #44444400 graya(68,0)
        13: ( 71, 71, 71,  0) #47474700 graya(71,0)
         3: ( 72, 72, 72,  0) #48484800 graya(72,0)
        15: ( 74, 74, 74,  0) #4A4A4A00 graya(74,0)
        14: ( 77, 77, 77,  0) #4D4D4D00 graya(77,0)
         9: ( 79, 79, 79,  0) #4F4F4F00 graya(79,0)
        21: ( 81, 81, 81,  0) #51515100 graya(81,0)
        31: ( 83, 83, 83,  0) #53535300 graya(83,0)
        87: ( 85, 85, 85,  0) #55555500 graya(85,0)
        48: ( 87, 87, 87,  0) #57575700 graya(87,0)
        89: ( 88, 88, 88,  0) #58585800 graya(88,0)
        71: ( 91, 91, 91,  0) #5B5B5B00 graya(91,0)
        90: ( 93, 93, 93,  0) #5D5D5D00 graya(93,0)
      1066: ( 95, 95, 95,  0) #5F5F5F00 graya(95,0)
        57: ( 97, 97, 97,  0) #61616100 graya(97,0)
        29: ( 99, 99, 99,  0) #63636300 graya(99,0)
        23: (100,100,100,  0) #64646400 graya(100,0)
        14: (102,102,102,  0) #66666600 graya(102,0)
        32: (105,105,105,  0) #69696900 graya(105,0)
        23: (106,106,106,  0) #6A6A6A00 graya(106,0)
        14: (109,109,109,  0) #6D6D6D00 graya(109,0)
        16: (110,110,110,  0) #6E6E6E00 graya(110,0)
        23: (113,113,113,  0) #71717100 graya(113,0)
        15: (115,115,115,  0) #73737300 graya(115,0)
        34: (116,116,116,  0) #74747400 graya(116,0)
        29: (119,119,119,  0) #77777700 graya(119,0)
        41: (120,120,120,  0) #78787800 graya(120,0)
        35: (122,122,122,  0) #7A7A7A00 graya(122,0)
        53: (125,125,125,  0) #7D7D7D00 graya(125,0)
        61: (127,127,127,  0) #7F7F7F00 graya(127,0)
        63: (129,129,129,  0) #81818100 graya(129,0)
       269: (131,131,131,  0) #83838300 graya(131,0)
        52: (133,133,133,  0) #85858500 graya(133,0)
        46: (134,134,134,  0) #86868600 graya(134,0)
        35: (137,137,137,  0) #89898900 graya(137,0)
        47: (139,139,139,  0) #8B8B8B00 graya(139,0)
        34: (141,141,141,  0) #8D8D8D00 graya(141,0)
        40: (143,143,143,  0) #8F8F8F00 graya(143,0)
       514: (144,144,144,  0) #90909000 graya(144,0)
        51: (146,146,146,  0) #92929200 graya(146,0)
        43: (149,149,149,  0) #95959500 graya(149,0)
        46: (150,150,150,  0) #96969600 graya(150,0)
        39: (152,152,152,  0) #98989800 graya(152,0)
        38: (155,155,155,  0) #9B9B9B00 graya(155,0)
        23: (156,156,156,  0) #9C9C9C00 graya(156,0)
        28: (158,158,158,  0) #9E9E9E00 graya(158,0)
        20: (161,161,161,  0) #A1A1A100 graya(161,0)
        20: (162,162,162,  0) #A2A2A200 graya(162,0)
        18: (164,164,164,  0) #A4A4A400 graya(164,0)
        29: (167,167,167,  0) #A7A7A700 graya(167,0)
        45: (169,169,169,  0) #A9A9A900 graya(169,0)
        33: (170,170,170,  0) #AAAAAA00 graya(170,0)
        31: (173,173,173,  0) #ADADAD00 graya(173,0)
        29: (175,175,175,  0) #AFAFAF00 graya(175,0)
        29: (177,177,177,  0) #B1B1B100 graya(177,0)
        29: (179,179,179,  0) #B3B3B300 graya(179,0)
        25: (180,180,180,  0) #B4B4B400 graya(180,0)
        34: (183,183,183,  0) #B7B7B700 graya(183,0)
        36: (185,185,185,  0) #B9B9B900 graya(185,0)
        24: (187,187,187,  0) #BBBBBB00 graya(187,0)
        33: (189,189,189,  0) #BDBDBD00 graya(189,0)
        25: (190,190,190,  0) #BEBEBE00 graya(190,0)
        31: (193,193,193,  0) #C1C1C100 graya(193,0)
        37: (194,194,194,  0) #C2C2C200 graya(194,0)
        33: (197,197,197,  0) #C5C5C500 graya(197,0)
        78: (198,198,198,  0) #C6C6C600 graya(198,0)
      1913: (200,200,200,  0) #C8C8C800 graya(200,0)
       181: (202,202,202,  0) #CACACA00 graya(202,0)
       141: (204,204,204,  0) #CCCCCC00 graya(204,0)
        97: (206,206,206,  0) #CECECE00 graya(206,0)
        82: (208,208,208,  0) #D0D0D000 graya(208,0)
        75: (210,210,210,  0) #D2D2D200 graya(210,0)
        48: (213,213,213,  0) #D5D5D500 graya(213,0)
        30: (214,214,214,  0) #D6D6D600 graya(214,0)
        17: (217,217,217,  0) #D9D9D900 graya(217,0)
        15: (218,218,218,  0) #DADADA00 graya(218,0)
        17: (221,221,221,  0) #DDDDDD00 graya(221,0)
        60: (222,222,222,  0) #DEDEDE00 graya(222,0)
        90: (224,224,224,  0) #E0E0E000 graya(224,0)
        47: (227,227,227,  0) #E3E3E300 graya(227,0)
        34: (229,229,229,  0) #E5E5E500 graya(229,0)
        42: (231,231,231,  0) #E7E7E700 graya(231,0)
        42: (233,233,233,  0) #E9E9E900 graya(233,0)
        25: (234,234,234,  0) #EAEAEA00 graya(234,0)
        30: (237,237,237,  0) #EDEDED00 graya(237,0)
        19: (239,239,239,  0) #EFEFEF00 graya(239,0)
        15: (241,241,241,  0) #F1F1F100 graya(241,0)
        19: (242,242,242,  0) #F2F2F200 graya(242,0)
        14: (245,245,245,  0) #F5F5F500 graya(245,0)
        96: (247,247,247,  0) #F7F7F700 graya(247,0)
        19: (248,248,248,  0) #F8F8F800 graya(248,0)
        13: (250,250,250,  0) #FAFAFA00 graya(250,0)
        17: (253,253,253,  0) #FDFDFD00 graya(253,0)
     23889: (255,255,255,  0) #FFFFFF00 graya(255,0)
  Rendering intent: Perceptual
  Gamma: 0.454545
  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: 210x150+0+0
  Dispose: Undefined
  Iterations: 0
  Compression: Undefined
  Orientation: Undefined
  Properties:
    date:create: 2014-09-21T22:39:19-07:00
    date:modify: 2014-09-21T22:32:53-07:00
    signature: e9aca15ae12529663a99f7527414a4c9c4e2e264a5f413d71706839c70435ecb
  Artifacts:
    filename: error.bmp
    verbose: true
  Tainted: True
  Filesize: 126KB
  Number pixels: 31.5K
  Pixels per second: 0B
  User time: 0.000u
  Elapsed time: 0:01.000
  Version: ImageMagick 6.8.9-7 Q16 x86_64 2014-08-27 http://www.imagemagick.org

Also

Code: Select all

convert error.bmp -alpha extract error_alpha.png
convert error.bmp -alpha off error_aoff.png

Thank you very much