Not a JPEG file: starts with 0x0a 0x4c Error

Question

I'm trying to import a bunch of images of .jpeg file format. However I'm getting the error

Not a JPEG file: starts with 0x0a 0x4c

Now, I know 0x89 0x50 is how .png files start. But I can't understand what 0x0a 0x4c represents.

I also ran the file image001.jpeg command on the terminal and it gave me

JPEG image data, JFIF standard 1.01.

Also, when I'm importing these group of images, this error is thrown for different files each time, not the same ones. So, I guess it isn't an issue of the file being corrupted.

If it helps, the image files were generated and saved on the hard disk through the imwrite() function of opencv.

Thanks

Using ImageMagick, the following verbose output is obtained.

Image: /Users/deathstroke/Desktop/lipRead/VidTIMIT/mwbt0/video/sx383/roi081.jpeg
  Format: JPEG (Joint Photographic Experts Group JFIF format)
  Mime type: image/jpeg
  Class: DirectClass
  Geometry: 68x39+0+0
  Units: Undefined
  Type: TrueColor
  Endianess: Undefined
  Colorspace: sRGB
  Depth: 8-bit
  Channel depth:
    red: 8-bit
    green: 8-bit
    blue: 8-bit
  Channel statistics:
    Pixels: 2652
    Red:
      min: 0 (0)
      max: 223 (0.87451)
      mean: 139.207 (0.54591)
      standard deviation: 44.1822 (0.173263)
      kurtosis: 0.798663
      skewness: -1.01178
      entropy: 0.942718
    Green:
      min: 0 (0)
      max: 159 (0.623529)
      mean: 87.1161 (0.341632)
      standard deviation: 33.4156 (0.131041)
      kurtosis: -0.162594
      skewness: -0.485596
      entropy: 0.955489
    Blue:
      min: 0 (0)
      max: 249 (0.976471)
      mean: 73.9367 (0.289948)
      standard deviation: 43.7079 (0.171403)
      kurtosis: 2.38585
      skewness: 1.43844
      entropy: 0.917047
  Image statistics:
    Overall:
      min: 0 (0)
      max: 249 (0.976471)
      mean: 100.087 (0.392496)
      standard deviation: 40.7392 (0.159761)
      kurtosis: 2.09684
      skewness: 0.445232
      entropy: 0.938418
  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: white
  Border color: srgb(223,223,223)
  Matte color: grey74
  Transparent color: black
  Interlace: None
  Intensity: Undefined
  Compose: Over
  Page geometry: 68x39+0+0
  Dispose: Undefined
  Iterations: 0
  Compression: JPEG
  Quality: 95
  Orientation: Undefined
  Properties:
    date:create: 2016-04-15T23:19:32+06:00
    date:modify: 2016-04-15T23:19:32+06:00
    jpeg:colorspace: 2
    jpeg:sampling-factor: 2x2,1x1,1x1
    signature: d3f2c14b57043efd4edbf719dfe769aded504df16c5b9fc8ee436d7551993221
  Artifacts:
    filename: /Users/deathstroke/Desktop/lipRead/VidTIMIT/mwbt0/video/sx383/roi081.jpeg
    verbose: true
  Tainted: False
  Filesize: 1.81KB
  Number pixels: 2.65K
  Pixels per second: 265KB
  User time: 0.000u
  Elapsed time: 0:01.009
  Version: ImageMagick 6.9.3-7 Q16 x86_64 2016-03-27 http://www.imagemagick.org

Answer 1

A JPEG Stream starts with an SOI marker FF D8. A JFIF file follows that with an APP0 marker FF E0.

It is entirely possible that you have a valid JPEG stream embedded somewhere in your data and that some applications are skipping over the non-jpeg data until they reach the SOI marker while other are puking on extraneous data.