imread

Parameters

filename: A string, the image filename to be read. The extension determines the type of the image.
Image: For truecolor images, this is a MxNx3 matrix in range 0-1 (double precision); For binary images, image is a MxNx1 matrix (0=black and 1=white).
Map: Mx3 matrix containing the image colormap. Entries range from 0 to 1 (double precision).

Description

imread reads BMP, GIF, JPEG, PNG, PCX, TIFF, XPM, and many more types of image files into Scilab. The format of the file is inferred from the extension in the filename parameter.

Img = imread(filename): reads image in filename into Img matrix. If filename contains a truecolor image, Img is a MxNx3 hypermatrix, so for example Img(:,:,1) stands for the red channel. For gray images, im is a MxNx1 matrix.
[Index,Map] = imread(filename): reads the indexed image in filename into Index (MxN) and Map (Mx3), its colormap. Grayscale and Paleliteraled images are read in this way.

To know if the image stored in filename is truecolor or indexed, you can use the imfinfo command, and then call imread accordingly.

Examples

initial_dir = PWD;
chdir (SIPDIR + 'images');

imfinfo('example.png','verbose');
// the image is indexed
[im,i] = imread('example.png');
clf;
imshow(im,i);

chdir(initial_dir);

File Formats

SIP should work with at least the following formats, but there is no warranty (unless you pay something :-). Please contact us in case of any problems.

Name      Mode   Description

o  8BIM      *rw Photoshop resource format
o  AFM       *r- TrueType font
o  APP1      *rw Photoshop resource format
o  ART       *r- PF1: 1st Publisher
o  AVI       *r- Audio/Visual Interleaved
o  AVS       *rw AVS X image
o  BIE       *rw Joint Bi-level Image experts Group
              interchange format
o  BMP       *rw Microsoft Windows bitmap image
o  CAPTION   *r+ Caption (requires separate size info)
o  CMYK      *rw Raw cyan, magenta, yellow, and black
              samples (8 or 16 bits, depending on
              the image depth)
o  CMYKA     *rw Raw cyan, magenta, yellow, black, and
              matte samples (8 or 16 bits, depending
              on the image depth)
o  CUT       *r- DR Halo
o  DCM       *r- Digital Imaging and Communications in
               Medicine image
o  DCX       *rw ZSoft IBM PC multi-page Paintbrush
o  DIB       *rw Microsoft Windows bitmap image
o  DPS       *r- Display PostScript
o  DPX       *r- Digital Moving Picture Exchange
o  EPDF      *rw Encapsulated Portable Document Format
o  EPI       *rw Adobe Encapsulated PostScript
              Interchange format
o  EPS       *rw Adobe Encapsulated PostScript
o  EPS2      *-w Adobe Level II Encapsulated PostScript
o  EPS3      *-w Adobe Level III Encapsulated PostScript
o  EPSF      *rw Adobe Encapsulated PostScript
o  EPSI      *rw Adobe Encapsulated PostScript
              Interchange format
o  EPT       *rw Adobe Encapsulated PostScript with TIFF
              preview
o  FAX       *rw Group 3 FAX
o  FILE      *r- Uniform Resource Locator
o  FITS      *rw Flexible Image Transport System
o  FPX       *rw FlashPix Format
o  FTP       *r- Uniform Resource Locator
o  G3        *rw Group 3 FAX
o  GIF       *rw CompuServe graphics interchange format
o  GIF87     *rw CompuServe graphics interchange format
              (version 87a)
o  GRADIENT  *r- Gradual passing from one shade to
              another
o  GRANITE   *r- Granite texture
o  GRAY      *rw Raw gray samples (8 or 16 bits,
              depending on the image depth)
o  H         *rw Internal format
o  HDF       -rw Hierarchical Data Format
o  HISTOGRAM *-w Histogram of the image
o  HTM       *-w Hypertext Markup Language and a
              client-side image map
o  HTML      *-w Hypertext Markup Language and a
              client-side image map
o  HTTP      *r- Uniform Resource Locator
o  ICB       *rw Truevision Targa image
o  ICM       *rw ICC Color Profile
o  ICO       *r- Microsoft icon
o  ICON      *r- Microsoft icon
o  IMPLICIT  *-- 
o  IPTC      *rw IPTC Newsphoto
o  JBG       *rw Joint Bi-level Image experts Group
              interchange format
o  JBIG      *rw Joint Bi-level Image experts Group
              interchange format
o  JP2       *rw JPEG-2000 JP2 File Format Syntax
o  JPC       *rw JPEG-2000 Code Stream Syntax
o  JPEG      *rw Joint Photographic Experts Group
              JFIF format
o  JPG       *rw Joint Photographic Experts Group
              JFIF format
o  LABEL     *r- Text image format
o  LOGO      *rw ImageMagick Logo
o  M2V       *rw MPEG-2 Video Stream
o  MAP       *rw Colormap intensities (8 or 16 bits,
              depending on the image depth) and
              indices (8 or 16 bits, depending
              on whether colors exceeds 256).
o  MAT       *-w MATLAB image format
o  MATTE     *-w MATTE format
o  MIFF      *rw Magick image format
o  MNG       *rw Multiple-image Network Graphics
o  MONO      *rw Bi-level bitmap in least-significant-
              -byte-first order
o  MPC       -rw Magick Persistent Cache image format
o  MPEG      *rw MPEG-1 Video Stream
o  MPG       *rw MPEG-1 Video Stream
o  MPR       *r- Magick Persistent Registry
o  MSL       *r- Magick Scripting Language
o  MTV       *rw MTV Raytracing image format
o  MVG       *rw Magick Vector Graphics
o  NETSCAPE  *r- Netscape 216 color cube
o  NULL      *r- Constant image of uniform color
o  OTB       *rw On-the-air bitmap
o  P7        *rw Xv thumbnail format
o  PAL       *rw 16bit/pixel interleaved YUV
o  PALM      *rw Palm Pixmap format
o  PBM       *rw Portable bitmap format (black and white)
o  PCD       *rw Photo CD
o  PCDS      *rw Photo CD
o  PCL       *-w Page Control Language
o  PCT       *rw Apple Macintosh QuickDraw/PICT
o  PCX       *rw ZSoft IBM PC Paintbrush
o  PDB       *r- Pilot Image Format
o  PDF       *rw Portable Document Format
o  PFA       *r- TrueType font
o  PFB       *r- TrueType font
o  PFM       *r- TrueType font
o  PGM       *rw Portable graymap format (gray scale)
o  PICON     *rw Personal Icon
o  PICT      *rw Apple Macintosh QuickDraw/PICT
o  PIX       *r- Alias/Wavefront RLE image format
o  PLASMA    *r- Plasma fractal image
o  PM        *rw X Windows system pixmap (color)
o  PNG       *rw Portable Network Graphics
o  PNM       *rw Portable anymap
o  PPM       *rw Portable pixmap format (color)
o  PREVIEW   *-w Show a preview an image enhancement,
              effect, or f/x
o  PS        *rw Adobe PostScript
o  PS2       *-w Adobe Level II PostScript
o  PS3       *-w Adobe Level III PostScript
o  PSD       *rw Adobe Photoshop bitmap
o  PTIF      *rw Pyramid encoded TIFF
o  PWP       *r- Seattle Film Works
o  RAS       *rw SUN Rasterfile
o  RGB       *rw Raw red, green, and blue samples (8 or
              16 bits, depending on the image depth)
o  RGBA      *rw Raw red, green, blue, and matte samples
              (8 or 16 bits, depending on the image
              depth)
o  RLA       *r- Alias/Wavefront image
o  RLE       *r- Utah Run length encoded image
o  ROSE      *rw 70x46 Truecolor test image
o  SCT       *r- Scitex HandShake
o  SFW       *r- Seattle Film Works
o  SGI       *rw Irix RGB image
o  SHTML     *-w Hypertext Markup Language and a
              client-side image map
o  STEGANO   *r- Steganographic image
o  SUN       *rw SUN Rasterfile
o  SVG       *rw Scalable Vector Gaphics
o  TEXT      *rw Raw text
o  TGA       *rw Truevision Targa image
o  TIF       *rw Tagged Image File Format
o  TIFF      *rw Tagged Image File Format
o  TILE      *r- Tile image with a texture
o  TIM       *r- PSX TIM
o  TTF       *r- TrueType font
o  TXT       *rw Raw text
o  UIL       *-w X-Motif UIL table
o  UYVY      *rw 16bit/pixel interleaved YUV
o  VDA       *rw Truevision Targa image
o  VICAR     *rw VICAR rasterfile format
o  VID       *rw Visual Image Directory
o  VIFF      *rw Khoros Visualization image
o  VST       *rw Truevision Targa image
o  WBMP      *rw Wireless Bitmap (level 0) image
o  WMF       *r- Windows Metafile
o  WPG       *r- Word Perfect Graphics
o  X         *rw X Image
o  XBM       *rw X Windows system bitmap (black
              and white)
o  XC        *r- Constant image uniform color
o  XCF       *r- GIMP image
o  XML       *r- Scalable Vector Gaphics
o  XPM       *rw X Windows system pixmap (color)
o  XV        *rw Khoros Visualization image
o  XWD       *rw X Windows system window dump (color)
o  YUV       *rw CCIR 601 4:1:1
               
Modes:         
          *    Native support (no call to external utility)
          r    Read
          w    Write

Bugs and Shortcomings

Images are stored in double precision matrices. Hopefully, the next release will make usage of integer types.

Authors

Ricardo Fabbri <ricardofabbri[at]users.sf.net>

Availability

The latest version of SIP can be found at

http://sip.sf.net