Write Binary Image from Matrix
in [Matlab]
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From: Matt on 28 Jan 2010 21:59 Hi -- I have a 2D array of ones and zeros and would like to write it as a binary bitmap. Seems simple, but I can't figure out how. What am I missing? Thanks.
From: ImageAnalyst on 28 Jan 2010 22:11 On Jan 28, 9:59 pm, "Matt " <m...(a)email.com> wrote: > Hi -- I have a 2D array of ones and zeros and would like to write it as a binary bitmap. Seems simple, but I can't figure out how. What am I missing? Thanks. --------------------------------------------------------------------------------------------------- Matt: You're missing the Image Processing Toolbox. In that toolbox is the imwrite() function, which can write BMP format images in a variety of bit depths. BMP Windows Bitmap Supported Bitdepths No Compression RLE Compression Output Class Notes 1-bit x logical 4-bit x x uint8 8-bit x x uint8 16-bit x uint8 1 sample/pixel 24-bit x uint8 3 samples/pixel 32-bit x uint8 3 samples/pixel (1 byte padding)
From: Matt on 28 Jan 2010 22:25 ImageAnalyst <imageanalyst(a)mailinator.com> wrote in message <0e5b2491-45b2-45d6-a684-5ec8771179ad(a)k19g2000yqc.googlegroups.com>... > On Jan 28, 9:59 pm, "Matt " <m...(a)email.com> wrote: > > Hi -- I have a 2D array of ones and zeros and would like to write it as a binary bitmap. Seems simple, but I can't figure out how. What am I missing? Thanks. > --------------------------------------------------------------------------------------------------- > Matt: > You're missing the Image Processing Toolbox. In that toolbox is the > imwrite() function, which can write BMP format images in a variety of > bit depths. Thanks for the reply -- I have the IPT, but when I just imwrite(M), where M is my matrix, the operation takes a very long time (~1 min for a 2000x1600 image). I suspect there is a better option?
From: Matt on 28 Jan 2010 22:37 ImageAnalyst <imageanalyst(a)mailinator.com> wrote in message <0e5b2491-45b2-45d6-a684-5ec8771179ad(a)k19g2000yqc.googlegroups.com>... > --------------------------------------------------------------------------------------------------- > Matt: > You're missing the Image Processing Toolbox. In that toolbox is the > imwrite() function, which can write BMP format images in a variety of > bit depths. Another thing -- when I use this method and open the resulting BMP in IrfanView, I just get a black image.
From: ImageAnalyst on 28 Jan 2010 22:57
What is the data type? What does it say when you use the "whos" command? It needs to be an integer not a floating point array. A small image like that should write out in just a few seconds, not a minute, if it were uint8. Probably your array is a double. Scale it to 0-255 and cast it to uint8 and see if that works. |