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Re: How to convert image into Hex 2 Dimensional Array?

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On 11/05/13 13:50, Arne Vajhøj wrote:
> On 5/11/2013 4:28 AM, lipska the kat wrote:
>> On 08/05/13 19:54, Joshua Cranmer 🐧 wrote:
>>> On 5/8/2013 12:40 PM, lipska the kat wrote:
>>>> On 08/05/13 17:52, Joshua Cranmer 🐧 wrote:
>>>>> On 5/8/2013 1:30 AM, sout saret wrote:
>>>>>> Dear Community!
>>>>>>
>>>>>> May you help me how to write code in java to convert image to Hex 2
>>>>>> dimensional array. I want to show format as below:
>>>>>
>>>>> What format is this two-dimensional array? Looking from your code, you
>>>>> appear to want it to be some sort of 256-byte pixel value, but are you
>>>>> desiring:
>>>>> 1. 8-bit ARGB
>>>>> 2. 5-6-5 RGB
>>>>> 3. 8-bit grayscale
>>>>> 4. 32-bit ARGB
>>>>> 5. 24-bit RGB
>>>>> 6. Binary version of any widely-used image format, including but not
>>>>> limited to PNG, BMP, GIF, JPG, XBM, TIF, and ICO.
>>>>
>>>> I think he wants a byte for byte copy so the first byte gets copied
>>>> into
>>>> [0][0] the next into [1][0] the next [2][0] etc until [width-1][0]
>>>> then start again at [0][1], [1][1], [2][1] etc etc
>>>
>>> A byte for byte copy of what? I'm guessing the answer is the "pixel
>>> matrix", but that's underdefined since pixels can take on many different
>>> formats, which is what I was trying to get at--what encoding of a pixel
>>> is desired?
>>
>> I've been thinking about this and actually, in a byte for byte copy
>> the 'encoding' of a pixel is irrelevant.
>>
>> If I open a (for example) jpg image in a hex viewer(ghex) all I see is
>> a bunch of bytes. As far as ghex is concerned that's all it is.
>> The bunch of bytes is only an image if it is interpreted as an image by
>> software that knows how to interpret the data *as an image*.
>>
>> So, as far as reading the data goes, all we have is a stream of bytes.
>>
>> If we want to store these bytes in a matrix(for whatever reason) we may
>> have an immediate problem. It may be the case that the byte count is not
>> a 'perfect square', what this means is that there may eventually be a
>> number matrix cells that will not contain data that is relevant to the
>> byte stream we are reading.
>>
>> So, how do we determine where in the matrix our data ends and the
>> default values used to populate the arrays on creation begin?
>>
>> If we use byte[][] we have a problem.
>> All byte values from 0x00 - 0xFF *could* be valid data,
>> byte arrays have each cell initialized to 0 (0x00)
>>
>> Byte arrays however have each cell initialized to null.
>>
>> It will therefore be very easy to determine the end of data in a
>> Byte[][] matrix. In a byte[][] matrix we would have to add some
>> information somewhere outside of the matrix.
>>
>> This situation only really applies if we wish to store our bytes in a
>> matrix. Obviously this is *not* a problem if we store the bytes in a
>> single dimension array.
>>
>> So, I'm not so sure that the original advice was as bad as all that, it
>> depends on the end usage of the stored data.
>>
>> As ever I'd be interested in any comments.
>
> Java 2D arrays are not necessarily square, so the second dimension
> can be different for each element of the first dimension. So it
> is also an option to use that instead of Byte[] with null fill
> to end.

Now *that's* interesting.

I can't say I've done much with byte matrices or any other matrix for 
that matter, or come to that, arrays, I generally tend to use dynamic 
storage components, like LinkedList<> for example. this seems to compile.

byte[][] bytes = new byte[2][];
bytes[0] = new byte[10];
bytes[1] = new byte[7];

I didn't know you could do that.

Well there you are, If I had ignored this thread I wouldn't have learned 
that.

comp.lang.java.programmer, gotta love it.

lipska

-- 
Lipska the Kat©: Troll hunter, sandbox destroyer
and farscape dreamer of Aeryn Sun

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Thread

How to convert image into Hex 2 Dimensional Array? sout saret <saretmis097@gmail.com> - 2013-05-07 23:30 -0700
  Re: How to convert image into Hex 2 Dimensional Array? lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-05-08 09:06 +0100
    Re: How to convert image into Hex 2 Dimensional Array? Joerg Meier <joergmmeier@arcor.de> - 2013-05-08 12:29 +0200
      Re: How to convert image into Hex 2 Dimensional Array? lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-05-08 13:28 +0100
    Re: How to convert image into Hex 2 Dimensional Array? Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2013-05-08 15:19 +0200
      Re: How to convert image into Hex 2 Dimensional Array? lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-05-08 14:57 +0100
        Re: How to convert image into Hex 2 Dimensional Array? Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2013-05-08 08:22 -0700
          Re: How to convert image into Hex 2 Dimensional Array? lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-05-08 17:03 +0100
            Re: How to convert image into Hex 2 Dimensional Array? Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2013-05-08 13:44 -0700
          Re: How to convert image into Hex 2 Dimensional Array? lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-05-08 17:48 +0100
            Re: How to convert image into Hex 2 Dimensional Array? Arne Vajhøj <arne@vajhoej.dk> - 2013-05-08 21:10 -0400
          Re: How to convert image into Hex 2 Dimensional Array? Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-05-08 12:52 -0400
        Re: How to convert image into Hex 2 Dimensional Array? Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2013-05-08 17:32 +0200
          Re: How to convert image into Hex 2 Dimensional Array? lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-05-08 17:17 +0100
            Re: How to convert image into Hex 2 Dimensional Array? Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2013-05-08 18:46 +0200
              Re: How to convert image into Hex 2 Dimensional Array? lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-05-08 18:25 +0100
                Re: How to convert image into Hex 2 Dimensional Array? Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2013-05-08 23:24 +0200
        Re: How to convert image into Hex 2 Dimensional Array? Joshua Cranmer 🐧 <Pidgeot18@verizon.invalid> - 2013-05-08 11:46 -0500
        Re: How to convert image into Hex 2 Dimensional Array? Arne Vajhøj <arne@vajhoej.dk> - 2013-05-08 21:04 -0400
          Re: How to convert image into Hex 2 Dimensional Array? Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-05-08 21:45 -0400
            Re: How to convert image into Hex 2 Dimensional Array? Arne Vajhøj <arne@vajhoej.dk> - 2013-05-08 21:59 -0400
              Re: How to convert image into Hex 2 Dimensional Array? Arne Vajhøj <arne@vajhoej.dk> - 2013-05-08 22:03 -0400
                Re: How to convert image into Hex 2 Dimensional Array? Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2013-05-09 04:09 +0200
                Re: How to convert image into Hex 2 Dimensional Array? Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2013-05-09 04:09 +0200
                Re: How to convert image into Hex 2 Dimensional Array? Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-05-08 23:18 -0400
                Re: How to convert image into Hex 2 Dimensional Array? Arne Vajhøj <arne@vajhoej.dk> - 2013-05-09 22:05 -0400
                Re: How to convert image into Hex 2 Dimensional Array? Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2013-05-10 09:46 -0700
                Re: How to convert image into Hex 2 Dimensional Array? Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2013-05-10 19:02 +0200
                Re: How to convert image into Hex 2 Dimensional Array? Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2013-05-10 11:00 -0700
                Re: How to convert image into Hex 2 Dimensional Array? Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2013-05-10 23:42 +0200
                Re: How to convert image into Hex 2 Dimensional Array? Arne Vajhøj <arne@vajhoej.dk> - 2013-05-10 18:20 -0400
    Re: How to convert image into Hex 2 Dimensional Array? Jeff Higgins <jeff@invalid.invalid> - 2013-05-08 12:43 -0400
      Re: How to convert image into Hex 2 Dimensional Array? lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-05-08 18:45 +0100
  Re: How to convert image into Hex 2 Dimensional Array? Jeff Higgins <jeff@invalid.invalid> - 2013-05-08 11:18 -0400
  Re: How to convert image into Hex 2 Dimensional Array? Joshua Cranmer 🐧 <Pidgeot18@verizon.invalid> - 2013-05-08 11:52 -0500
    Re: How to convert image into Hex 2 Dimensional Array? lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-05-08 18:40 +0100
      Re: How to convert image into Hex 2 Dimensional Array? Joshua Cranmer 🐧 <Pidgeot18@verizon.invalid> - 2013-05-08 13:54 -0500
        Re: How to convert image into Hex 2 Dimensional Array? lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-05-08 20:43 +0100
        Re: How to convert image into Hex 2 Dimensional Array? lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-05-11 09:28 +0100
          Re: How to convert image into Hex 2 Dimensional Array? Arne Vajhøj <arne@vajhoej.dk> - 2013-05-11 08:50 -0400
            Re: How to convert image into Hex 2 Dimensional Array? lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-05-11 15:00 +0100
              Re: How to convert image into Hex 2 Dimensional Array? Arne Vajhøj <arne@vajhoej.dk> - 2013-05-12 21:45 -0400
  Re: How to convert image into Hex 2 Dimensional Array? Manuel Dahmen <manuel.dahmen@gmail.com> - 2013-05-08 15:38 -0700
  Re: How to convert image into Hex 2 Dimensional Array? Roedy Green <see_website@mindprod.com.invalid> - 2013-05-11 13:33 -0700
    Re: How to convert image into Hex 2 Dimensional Array? Arne Vajhøj <arne@vajhoej.dk> - 2013-05-12 21:48 -0400
      Re: How to convert image into Hex 2 Dimensional Array? markspace <markspace@nospam.nospam> - 2013-05-12 20:49 -0700
        Re: How to convert image into Hex 2 Dimensional Array? Arne Vajhøj <arne@vajhoej.dk> - 2013-05-13 19:08 -0400
        Re: How to convert image into Hex 2 Dimensional Array? Roedy Green <see_website@mindprod.com.invalid> - 2013-05-15 03:45 -0700
        Re: How to convert image into Hex 2 Dimensional Array? Roedy Green <see_website@mindprod.com.invalid> - 2013-05-15 03:50 -0700

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