PDL::IO::Image - Load/save bitmap from/to PDL (via FreeImage library)
Functional interface:
use 5.010; use PDL; use PDL::IO::Image; my $pdl1 = rimage('picture.tiff'); say $pdl1->info; # PDL: Byte D [400,300] ... width 400, height 300 # do some hacking with $piddle wimage($pdl1, 'output.tiff'); # you can also use wimage as PDL's method $pdl1->wimage('another-output.png'); my ($pixels, $palette) = rimage('picture-256colors.gif', { palette=>1 }); say $pixels->info; # PDL: Byte D [400,300] ... width 400, height 300 say $palette->info; # PDL: Byte D [3,256] # do some hacking with $pixels and $palette wimage($pixels, 'output.gif', { palette=>$palette }); # load specific image (page) from multi-page file my $pdl2 = rimage('picture.tiff', { page=>0 }); # load specific image + flit vertically before converting to piddle my $pdl3 = rimage('picture.tiff', { flip=>'V' }); # random pixels + ramdom colors (RGBA - 35 bits per pixel) (random(400, 300, 4) * 256)->byte->wimage("random.png"); my $pix1 = (sin(0.25 * rvals(101, 101)) * 128 + 127)->byte; say $pix1->info; # PDL: Byte D [101,101] my $pal1 = yvals(3, 256)->byte; $pal1->slice("(2),:") .= 0; # set blue part of palette to zero say $pal1->info; # PDL: Byte D [3,256] $pix1->wimage("wave1_grayscale.gif"); # default is grayscale palette $pix1->wimage("wave2_yellow.gif", { palette=>$pal1 }); # rotate /rescale before saving my $pix2 = (sin(0.25 * xvals(101, 101)) * 128 + 127)->byte; $pix2->wimage("wave3_grayscale.gif", { rescale=>[16,16] }); # rescale to 16x16 pixels $pix2->wimage("wave4_grayscale.gif", { rescale_pct=>50 }); # rescale to 50% $pix2->wimage("wave5_grayscale.gif", { rotate=>33.33 });
Object oriented (OO) interface:
use 5.010; use PDL; use PDL::IO::Image; # create PDL::IO::Image object from file my $pimage1 = PDL::IO::Image->new_from_file('picture.gif'); say 'width = ' . $pimage1->get_width; say 'height = ' . $pimage1->get_height; say 'image_type = ' . $pimage1->get_image_type; say 'color_type = ' . $pimage1->get_color_type; say 'colors_used = ' . $pimage1->get_colors_used; say 'bpp = ' . $pimage1->get_bpp; # you can do some operations with PDL::IO::Image object $pimage1->flip_vertical; # export pixels from PDL::IO::Image object content into a piddle my $pix_pdl = $pimage1->pixels_to_pdl(); # export palette from PDL::IO::Image object content into a piddle my $pal_pdl = $pimage1->palette_to_pdl(); # let us have a piddle with pixel data my $wave_pixels = (sin(0.008 * xvals(2001, 2001)) * 128 + 127)->byte; # create PDL::IO::Image object from PDL piddle my $pimage2 = PDL::IO::Image->new_from_pdl($wave_pixels); # do some transformation with PDL::IO::Image object $pimage2->rotate(45); $pimage2->rescale(200, 200); # export PDL::IO::Image object content into a image file $pimage2->save("output.jpg");
PDL::IO::Image implements I/O for a number of popular image formats. It is based on "FreeImage library" however there is no need to install FreeImage library on your system because PDL::IO::Image uses Alien::FreeImage module which handles building FreeImage library from sources (works on Windows, Cygwin, Mac OS X, Linux and other UNIXes).
Check also an excellent FreeImage documentation at http://freeimage.sourceforge.net/documentation.html
This module supports loading ("new_from_file" or "rimage") and saving ("save" or "wimage") of the following formats (note that not all formats support writing - see R/W column).
R/W
BMP R/W Windows or OS/2 Bitmap [extensions: bmp] ICO R/W Windows Icon [extensions: ico] JPEG R/W JPEG - JFIF Compliant [extensions: jpg,jif,jpeg,jpe] JNG R/W JPEG Network Graphics [extensions: jng] KOALA R/- C64 Koala Graphics [extensions: koa] IFF R/- IFF Interleaved Bitmap [extensions: iff,lbm] MNG R/- Multiple-image Network Graphics [extensions: mng] PBM R/W Portable Bitmap (ASCII) [extensions: pbm] PBMRAW R/W Portable Bitmap (RAW) [extensions: pbm] PCD R/- Kodak PhotoCD [extensions: pcd] PCX R/- Zsoft Paintbrush [extensions: pcx] PGM R/W Portable Greymap (ASCII) [extensions: pgm] PGMRAW R/W Portable Greymap (RAW) [extensions: pgm] PNG R/W Portable Network Graphics [extensions: png] PPM R/W Portable Pixelmap (ASCII) [extensions: ppm] PPMRAW R/W Portable Pixelmap (RAW) [extensions: ppm] RAS R/- Sun Raster Image [extensions: ras] TARGA R/W Truevision Targa [extensions: tga,targa] TIFF R/W Tagged Image File Format [extensions: tif,tiff] WBMP R/W Wireless Bitmap [extensions: wap,wbmp,wbm] PSD R/- Adobe Photoshop [extensions: psd] CUT R/- Dr. Halo [extensions: cut] XBM R/- X11 Bitmap Format [extensions: xbm] XPM R/W X11 Pixmap Format [extensions: xpm] DDS R/- DirectX Surface [extensions: dds] GIF R/W Graphics Interchange Format [extensions: gif] HDR R/W High Dynamic Range Image [extensions: hdr] G3 R/- Raw fax format CCITT G.3 [extensions: g3] SGI R/- SGI Image Format [extensions: sgi,rgb,rgba,bw] EXR R/W ILM OpenEXR [extensions: exr] J2K R/W JPEG-2000 codestream [extensions: j2k,j2c] JP2 R/W JPEG-2000 File Format [extensions: jp2] PFM R/W Portable floatmap [extensions: pfm] PICT R/- Macintosh PICT [extensions: pct,pict,pic] RAW R/- RAW camera image [extensions: 3fr,arw,bay,bmq,cap,cine, cr2,crw,cs1,dc2, dcr,drf,dsc,dng,erf,fff,ia,iiq,k25, kc2,kdc,mdc,mef,mos,mrw,nef,nrw,orf,pef, ptx,pxn,qtk, raf,raw,rdc,rw2,rwl,rwz,sr2,srf,srw,sti] WEBP R/W Google WebP image format [extensions: webp] JPEG-XR R/W JPEG XR image format [extensions: jxr,wdp,hdp]
IMPORTANT the strings in the first column (e.g. 'BMP', 'JPEG', 'PNG') are used as a format identifier in "new_from_file", "save", "rimage", "wimage" (+some other methods).
'BMP'
'JPEG'
'PNG'
The supported format may differ depending on FreeImage library version. You can list what exactly you FreeImage library can handle like this:
for (PDL::IO::Image->format_list) { my $r = PDL::IO::Image->format_can_read($_) ? 'R' : '-'; my $w = PDL::IO::Image->format_can_write($_) ? 'W' : '-'; my $e = PDL::IO::Image->format_extension_list($_); my $d = PDL::IO::Image->format_description($_); printf("% 7s %s/%s %s [extensions: %s]\n", $_, $r, $w, $d, $e); }
This module can handle the following image types.
BITMAP Standard image: 1-, 4-, 8-, 16-, 24-, 32-bit UINT16 Array of unsigned short: unsigned 16-bit INT16 Array of short: signed 16-bit UINT32 Array of unsigned long: unsigned 32-bit INT32 Array of long: signed 32-bit FLOAT Array of float: 32-bit IEEE floating point DOUBLE Array of double: 64-bit IEEE floating point RGB16 48-bit RGB image: 3 x 16-bit RGBA16 64-bit RGBA image: 4 x 16-bit RGBF 96-bit RGB float image: 3 x 32-bit IEEE floating point RGBAF 128-bit RGBA float image: 4 x 32-bit IEEE floating point
Currently NOT SUPPORTED:
COMPLEX Array of FICOMPLEX: 2 x 64-bit IEEE floating point
Image type is important especially when you want to load image data from PDL piddle into a PDL::IO::Image object (and later save to a file). Based on piddle size and piddle type the image type is detected (in "new_from_pdl" and "wimage").
W .. image width H .. image height PDL Byte [W,H] BITMAP 1-/4-/8-bits per pixel PDL Byte [W,H,3] BITMAP 24-bits per pixel (RGB) PDL Byte [W,H,4] BITMAP 32-bits per pixel (RGBA) PDL Ushort [W,H] UINT16 PDL Short [W,H] INT16 PDL LongLong [W,H] UINT32 (unfortunately there is no PDL Ulong type) PDL Long [W,H] INT32 PDL Float [W,H] FLOAT PDL Double [W,H] DOUBLE PDL Ushort [W,H,3] RGB16 PDL Ushort [W,H,4] RGBA16 PDL Float [W,H,3] RGBf PDL Float [W,H,4] RGBAF
IMPORTANT the strings with type name (e.g. 'BITMAP', 'UINT16', 'RGBAF') are used as a image type identifier in method "convert_image_type" and a return value of method "get_image_type".
'BITMAP'
'UINT16'
'RGBAF'
Not all file formats support all image formats above (especially those non-BITMAP image types). If you are in doubts use tiff format for storing unusual image types.
tiff
The functional interface comprises of two functions "rimage" and "wimage" - both are exported by default.
Loads image into a PDL piddle (or into two piddles in case of palette-based images).
my $pixels_pdl = rimage($filename); #or my $pixels_pdl = rimage($filename, \%options); #or my ($pixels_pdl, $palette_pdl) = rimage($filename, { palette=>1 });
Internally it works in these steps:
Create PDL::IO::Image object from the input file.
Do optional transformations (based on %options) with PDL::IO::Image object.
%options
Export PDL::IO::Image object into a piddle(s) via "pixels_to_pdl" and "palette_to_pdl".
IMPORTANT: "rimage" returns piddle(s) not a PDL::IO::Image object
Items supported in options hash:
format
String identifying file format (e.g. 'JPEG' - for valid values see "Supported file formats"), default is 'AUTO' which means that format is auto detected.
'AUTO'
format_flag
Optional flag related to loading given file format - see "new_from_file" method for more info.
page
Index (0-based) of a specific page to load from multi-page images (TIFF, ICO or animated GIF).
flip
Values 'H', 'V' or 'HV' specifying horizontal, vertical or horizontal+vertical flipping. Default: do not flip.
'H'
'V'
'HV'
rotate
Optional floating point value with rotation angle (in degrees) - see "rotate" method for more info. Default: do not rotate.
convert_image_type
String identifying image type (e.g. 'BITMAP' - for valid values see "Supported image types"). Default: no conversion.
region
An arrayref with a region specification like [$x1,$x2,$y1,$y2] - see "pixels_to_pdl" method for more info. Default: create the output piddle from the whole image.
[$x1,$x2,$y1,$y2]
palette
Values 0 (default) or 1 - whether to load (or not) color lookup table (aka LUT).
0
1
Write PDL piddle(s) into a image file.
$pixels_pdl->wimage($filename); #or $pixels_pdl->wimage($filename, \%options); wimage($pixels_pdl, $filename); #or wimage($pixels_pdl, $filename, \%options);
Create PDL::IO::Image object from the $pixels_piddle (+ $palette_piddle passed as palette option).
$pixels_piddle
$palette_piddle
Dimensions and type of $pixels_piddle must comply with "Supported image types".
Export PDL::IO::Image object into a image file via "save" method.
String identifying file format (e.g. 'JPEG' - for valid values see "Supported file formats"), default is 'AUTO' which means that format is auto detected from extension of $filename.
$filename
Optional flag related to saving given file format - see "save" method for more info.
Optional PDL piddle with color palette (has to be PDL Byte[3,N] where 0 < N <= 256) containing RGB triplets.
PDL Byte[3,N]
rescale
Optional arrayref with rescale specification (in pixels) e.g. [$new_w, $new_h] - see "rescale" method for more info. Default: do not rescale.
[$new_w, $new_h]
rescale_pct
Optional floating point value with rescale ratio in percent - see "rescale_pct" method for more info. Default: do not rescale.
Create PDL::IO::Image object from image file.
my $pimage = IO::PDL::Image->new_from_file($filename); #or my $pimage = IO::PDL::Image->new_from_file($filename, $format); #or my $pimage = IO::PDL::Image->new_from_file($filename, $format, $format_flag); #or my $pimage = IO::PDL::Image->new_from_file($filename, $format, $format_flag, $page); #if you have image file content in a scalar variable you can use my $pimage = IO::PDL::Image->new_from_file(\$variable_with_image_data);
$filename - input image file name or a reference to scalar variable with imiga data.
$format - string identifying file format (e.g. 'JPEG' - for valid values see "Supported file formats"), default is 'AUTO' which means that format is auto detected (based on file header with fall-back to detection based on file extension).
$format
$format_flag - optional flag related to loading given file format, default if 0 (no extra flags). The flag can be created by OR-ing some of available constants:
$format_flag
PDL::IO::Image::GIF_LOAD256 Load the image as a 256 color image with unused palette entries, if it's 16 or 2 color PDL::IO::Image::GIF_PLAYBACK 'Play' the GIF to generate each frame (as 32bpp) instead of returning raw frame data when loading PDL::IO::Image::ICO_MAKEALPHA Convert to 32-bit and create an alpha channel from the ANDmask when loading PDL::IO::Image::JPEG_FAST Load the file as fast as possible, sacrificing some quality PDL::IO::Image::JPEG_ACCURATE Load the file with the best quality, sacrificing some speed PDL::IO::Image::JPEG_CMYK This flag will load CMYK bitmaps as 32-bit separated CMYK PDL::IO::Image::JPEG_GREYSCALE Load and convert to a 8-bit greyscale image (faster than loading as 24-bit and converting to 8-bit) PDL::IO::Image::JPEG_EXIFROTATE Load and rotate according to Exif 'Orientation' tag if available PDL::IO::Image::PCD_BASE This flag will load the one sized 768 x 512 PDL::IO::Image::PCD_BASEDIV4 This flag will load the bitmap sized 384 x 256 PDL::IO::Image::PCD_BASEDIV16 This flag will load the bitmap sized 192 x 128 PDL::IO::Image::PNG_IGNOREGAMMA Avoid gamma correction on loading PDL::IO::Image::PSD_CMYK Reads tags for separated CMYK (default is conversion to RGB) PDL::IO::Image::PSD_LAB Reads tags for CIELab (default is conversion to RGB) PDL::IO::Image::RAW_PREVIEW Try to load the embedded JPEG preview with included Exif data or default to RGB 24-bit PDL::IO::Image::RAW_DISPLAY Load the file as RGB 24-bit PDL::IO::Image::RAW_HALFSIZE Output a half-size color image PDL::IO::Image::TARGA_LOAD_RGB888 If set the loader converts RGB555 and ARGB8888 -> RGB888 PDL::IO::Image::TIFF_CMYK Load CMYK bitmaps as separated CMYK (default is conversion to RGB)
Create PDL::IO::Image object from PDL piddle with pixel (+ optional palette) data.
my $pimage = IO::PDL::Image->new_from_pdl($pixels_pdl); #or my $pimage = IO::PDL::Image->new_from_pdl($pixels_pdl, $palette_pdl);
$pixels_pdl - PDL piddle containing pixel data, dimensions and type must comply with "Supported image types".
$pixels_pdl
$palette_pdl - Optional PDL piddle with color palette (has to be PDL Byte[3,N] where 0 < N <= 256) containing RGB triplets.
$palette_pdl
Create a copy (clone) of PDL::IO::Image object.
my $pimage_copy = $pimage->clone();
Export pixel data from PDL::IO::Image object into a piddle.
my $pixels_pdl = $pimage->pixels_to_pdl; #or my $pixels_pdl = $pimage->pixels_to_pdl($x1, $x2, $y1, $y2);
$x1, $x2, $y1, $y2 - Optional specification of image sub-region to be exported. All values are 0-based, negative values can be used to specify boundary "from the end".
$x1, $x2, $y1, $y2
Export palette (aka LUT - color lookup table) data from PDL::IO::Image object into a piddle.
my $palette_pdl = $pimage->palette_to_pdl;
The output piddle is ususally PDL Byte [3, 256]. Returns undef if image represented by $pimage does not use palette.
PDL Byte [3, 256]
undef
$pimage
Export PDL::IO::Image object into a image file.
$pimage->save($filename, $format, $flags); #or $pimage->save($filename, $format); #or $pimage->save($filename); #you can save the image data to a variable like this my $output_image; $pimage->save(\$output_image, $format); #NOTE: $format is mandatory in this case
Returns $pimage (self).
$filename - output image file name or a reference to perl scalar variable.
$format - string identifying file format (e.g. 'JPEG' - for valid values see "Supported file formats"), default is 'AUTO' which means that format is auto detected from extension of $filename.
$format_flag - optional flag related to saving given file format, default if 0 (no extra flags). The flag can be created by OR-ing some of available constants:
PDL::IO::Image::BMP_SAVE_RLE Compress the bitmap using RLE when saving PDL::IO::Image::EXR_FLOAT Save data as float instead of as half (not recommended) PDL::IO::Image::EXR_NONE Save with no compression PDL::IO::Image::EXR_ZIP Save with zlib compression, in blocks of 16 scan lines PDL::IO::Image::EXR_PIZ Save with piz-based wavelet compression PDL::IO::Image::EXR_PXR24 Save with lossy 24-bit float compression PDL::IO::Image::EXR_B44 Save with lossy 44% float compression PDL::IO::Image::EXR_LC Save with one luminance and two chroma channels, rather than RGB (lossy) for J2K format: integer X in [1..512] Save with a X:1 rate (default = 16) for JP2 format: integer X in [1..512] Save with a X:1 rate (default = 16) PDL::IO::Image::JPEG_QUALITYSUPERB Saves with superb quality (100:1) PDL::IO::Image::JPEG_QUALITYGOOD Saves with good quality (75:1 - default) PDL::IO::Image::JPEG_QUALITYNORMAL Saves with normal quality (50:1) PDL::IO::Image::JPEG_QUALITYAVERAGE Saves with average quality (25:1) PDL::IO::Image::JPEG_QUALITYBAD Saves with bad quality (10:1) for JPEG format: integer X in [0..100] Save with quality X:1 PDL::IO::Image::JPEG_PROGRESSIVE Saves as a progressive JPEG file PDL::IO::Image::JPEG_SUBSAMPLING_411 Save with high 4x1 chroma subsampling (4:1:1) PDL::IO::Image::JPEG_SUBSAMPLING_420 Save with medium 2x2 chroma subsampling (4:2:0) - default value PDL::IO::Image::JPEG_SUBSAMPLING_422 Save with low 2x1 chroma subsampling (4:2:2) PDL::IO::Image::JPEG_SUBSAMPLING_444 Save with no chroma subsampling (4:4:4) PDL::IO::Image::JPEG_OPTIMIZE On saving, compute optimal Huffman coding tables PDL::IO::Image::JPEG_BASELINE Save basic JPEG, without metadata or any markers for JXR format: integer X in [1..100) Save with quality X:1 (default = 80), using X=100 means lossless PDL::IO::Image::JXR_LOSSLESS Save lossless (quality = 100) PDL::IO::Image::JXR_PROGRESSIVE Saves as a progressive JPEG-XR file PDL::IO::Image::PNG_Z_BEST_SPEED Save using ZLib level 1 compression (default value is 6) PDL::IO::Image::PNG_Z_DEFAULT_COMPRESSION Save using ZLib level 6 compression (default) PDL::IO::Image::PNG_Z_BEST_COMPRESSION Save using ZLib level 9 compression (default value is 6) PDL::IO::Image::PNG_Z_NO_COMPRESSION Save without ZLib compression PDL::IO::Image::PNG_INTERLACED Save using Adam7 interlacing PDL::IO::Image::PNM_SAVE_RAW Saves the bitmap as a binary file PDL::IO::Image::PNM_SAVE_ASCII Saves the bitmap as an ASCII file PDL::IO::Image::TIFF_CMYK Stores tags for separated CMYK PDL::IO::Image::TIFF_PACKBITS Save using PACKBITS compression PDL::IO::Image::TIFF_DEFLATE Save using DEFLATE compression (also known as ZLIB compression) PDL::IO::Image::TIFF_ADOBE_DEFLATE Save using ADOBE DEFLATE compression PDL::IO::Image::TIFF_NONE Save without any compression PDL::IO::Image::TIFF_CCITTFAX3 Save using CCITT Group 3 fax encoding PDL::IO::Image::TIFF_CCITTFAX4 Save using CCITT Group 4 fax encoding PDL::IO::Image::TIFF_LZW Save using LZW compression PDL::IO::Image::TIFF_JPEG Save using JPEG compression (8-bit greyscale and 24-bit only) PDL::IO::Image::TIFF_LOGLUV Save using LogLuv compression (only available with RGBF images PDL::IO::Image::TARGA_SAVE_RLE Save with RLE compression
Extract raw bitmap data (+ do necessary image type and/or bpp conversions).
my ($width, $height, $bpp, $pixels, $palette) = $pimage->dump_bitmap; #or my ($width, $height, $bpp, $pixels, $palette) = $pimage->dump_bitmap($required_bpp);
$pixels and $palette are raw data buffers containg sequence of RGB (RGBA) byte values.
$pixels
$palette
$required_bpp can be 8, 24 or 32 - before dumping the image is converted to BITMAP image type + colors depth is converted to given value. Default is autodetect the lowest sufficient bpp (from 8, 24, 32).
$required_bpp
BITMAP
Returns the data type of a bitmap (e.g. 'BITMAP', 'UINT16') - see "Supported image types".
my $imtype = $pimage->get_image_type;
Returns the palette size for palletised bitmaps (usually 256), and 0 for high-colour bitmaps.
my $colors = $pimage->get_colors_used;
Returns the size of one pixel in the bitmap in bits (aka bits per pixel).
my $bpp = $pimage->get_bpp;
Returns the width of the bitmap in pixels.
my $w = $pimage->get_width;
Returns the height of the bitmap in pixels.
my $h = $pimage->get_height;
Returns the horizontal resolution, in pixels-per-meter.
my $dpmx = $pimage->get_dots_per_meter_x;
Set the horizontal resolution, in pixels-per-meter.
$pimage->set_dots_per_meter_x($res);
Returns the vertical resolution, in pixels-per-meter.
my $dpmy = $pimage->get_dots_per_meter_y;
Set the vertical resolution, in pixels-per-meter.
$pimage->set_dots_per_meter_y($res);
Returns color type.
my $coltype = $pimage->get_color_type;
The return value is a string:
'MINISBLACK' Monochrome bitmap (1-bit): first palette entry is black. Palletised bitmap (4 or 8-bit) and single channel non standard bitmap: greyscale palette 'MINISWHITE' Monochrome bitmap (1-bit): first palette entry is white. Palletised bitmap (4 or 8-bit): inverted greyscale palette 'PALETTE' Palettized bitmap (1, 4 or 8 bit) 'RGB' High-color bitmap (16, 24 or 32 bit), RGB16 or RGBF 'RGBALPHA' High-color bitmap with an alpha channel (32 bit bitmap, RGBA16 or RGBAF) 'CMYK' CMYK bitmap (32 bit only)
Returns 1 when the transparency table is enabled (1-, 4- or 8-bit images) or when the input dib contains alpha values (32-bit images, RGBA16 or RGBAF images). Returns 0 otherwise.
my $bool = $pimage->is_transparent;
Returns the palette entry used as transparent color for the image specified. Works for palletised images only and returns -1 for high color images or if the image has no color set to be transparent.
my $idx = $pimage->get_transparent_index;
Sets the index of the palette entry to be used as transparent color for the image specified. Does nothing on high color images.
$pimage->set_transparent_index($index);
Flip the image horizontally along the vertical axis.
$pimage->flip_horizontal;
Flip the image vertically along the horizontal axis.
$pimage->flip_vertical;
Rotates image, the angle of counter clockwise rotation is specified by the $angle parameter in degrees.
$angle
$pimage->rotate($angle); #or $pimage->rotate($angle, $bg_r, $bg_g, $bg_b, $bg_a); # RGBA(F|16) images $pimage->rotate($angle, $bg_r, $bg_g, $bg_b); # RGB(F|16) images $pimage->rotate($angle, $bg); # palette-based images
You can specify optional backgroung color via $bg_r, $bg_g, $bg_b, $bg_a or $bg.
$bg_r
$bg_g
$bg_b
$bg_a
$bg
Performs resampling (scaling/zooming) of a greyscale or RGB(A) image to the desired destination width and height.
$pimage->rescale($dst_width, $dst_height, $filter); #or $pimage->rescale($dst_width, 0); # destination height is computed #or $pimage->rescale(0, $dst_height); # destination width is computed
$filter - resampling filter identifier:
$filter
0 .. Box, pulse, Fourier window, 1st order (constant) b-spline 1 .. Mitchell & Netravali's two-param cubic filter 2 .. Bilinear filter 3 .. 4th order (cubic) b-spline 4 .. Catmull-Rom spline, Overhauser spline 5 .. Lanczos3 filter
Performs resampling by given percentage ratio.
$pimage->rescale($dst_width_pct, $dst_height_pct, $filter); #or $pimage->rescale($dst_pct);
$filter - see "rescale"
Converts an image to destination $image_type.
$image_type
$pimage->convert_image_type($image_type, $scale_linear); #or $pimage->convert_image_type($image_type);
$image_type - string identifying image type (e.g. 'BITMAP', 'UINT16' - for valid values see "Supported image types").
Adjusts an image's brightness, contrast and gamma as well as it may optionally invert the image within a single operation.
$pimage->adjust_colors($brightness, $contrast, $gamma, $invert);
$brightness - real value from range [-100..100], value 0 means no change, less than 0 will make the image darker and greater than 0 will make the image brighter
$brightness
[-100..100]
$contrast - real value from range [-100..100], value 0 means no change, less than 0 will decrease the contrast and greater than 0 will increase the contrast of the image
$contrast
$gamma - real value greater than 0, value of 1.0 leaves the image alone, less than one darkens it, and greater than one lightens it
$gamma
$invert - 0 or 1 invert (or not) all pixels
$invert
Converts a bitmap to 4 bits. If the bitmap was a high-color bitmap (16, 24 or 32-bit) or if it was a monochrome or greyscale bitmap (1 or 8-bit), the end result will be a greyscale bitmap, otherwise (1-bit palletised bitmaps) it will be a palletised bitmap.
$pimage->color_to_4bpp();
Converts a bitmap to 8 bits. If the bitmap was a high-color bitmap (16, 24 or 32-bit) or if it was a monochrome or greyscale bitmap (1 or 4-bit), the end result will be a greyscale bitmap, otherwise (1 or 4-bit palletised bitmaps) it will be a palletised bitmap.
$pimage->color_to_8bpp();
Converts a bitmap to a 8-bit greyscale image with a linear ramp. Contrary to the FreeImage_ConvertTo8Bits function, 1-, 4- and 8-bit palletised images are correctly converted, as well as images with a FIC_MINISWHITE color type.
$pimage->color_to_8bpp_grey();
Converts a bitmap to 16 bits, where each pixel has a color pattern of 5 bits red, 5 bits green and 5 bits blue. One bit in each pixel is unused.
$pimage->color_to_16bpp_555();
Converts a bitmap to 16 bits, where each pixel has a color pattern of 5 bits red, 6 bits green and 5 bits blue.
$pimage->color_to_16bpp_565();
Converts a bitmap to 24 bits per pixel.
$pimage->color_to_24bpp();
Converts a bitmap to 32 bits per pixel.
$pimage->color_to_32bpp();
Converts a bitmap to 1-bit monochrome bitmap using a dithering algorithm.
$pimage->color_dither($algorithm); #or $pimage->color_dither();
Possible $algorithm values:
$algorithm
0 .. Floyd & Steinberg error diffusion (DEFAULT) 1 .. Bayer ordered dispersed dot dithering (order 2 dithering matrix) 2 .. Bayer ordered dispersed dot dithering (order 3 dithering matrix) 3 .. Ordered clustered dot dithering (order 3 - 6x6 matrix) 4 .. Ordered clustered dot dithering (order 4 - 8x8 matrix) 5 .. Ordered clustered dot dithering (order 8 - 16x16 matrix) 6 .. Bayer ordered dispersed dot dithering (order 4 dithering matrix)
Converts a bitmap to 1-bit monochrome bitmap using a $threshold between [0..255] (default is 127).
$threshold
$pimage->color_threshhold($threshold); #or $pimage->color_threshhold();
$pimage->color_quantize($quantize); #or $pimage->color_quantize();
Possible $quantize values:
$quantize
0 .. Xiaolin Wu color quantization algorithm 1 .. NeuQuant neural-net quantization algorithm by Anthony Dekker
Converts a High Dynamic Range image (48-bit RGB or 96-bit RGBF) to a 24-bit RGB image, suitable for display.
$pimage->tone_mapping($tone_mapping_operator, $param1, $param2);
$tone_mapping_operator - tone mapping operator identifier:
$tone_mapping_operator
0 .. Adaptive logarithmic mapping (F. Drago, 2003) 1 .. Dynamic range reduction inspired by photoreceptor physiology (E. Reinhard, 2005) 2 .. Gradient domain high dynamic range compression (R. Fattal, 2002)
Optional parameters:
$pimage->tone_mapping(0, $gamma, $exposure); #or $pimage->tone_mapping(1, $intensity, $contrast); #or $pimage->tone_mapping(2, $color_saturation, $attenuation);
Returns a string containing the current version of the library.
my $v = PDL::IO::Image->free_image_version();
Returns a list of all supported file formats.
my @f = PDL::IO::Image->format_list();
Returns a comma-delimited file extension list for given file format.
my $ext = PDL::IO::Image->format_extension_list($format);
$format - string identifying file format (e.g. 'JPEG' - for valid values see "Supported file formats").
Returns MIME content type string for given file format.
my $mtype = PDL::IO::Image->format_mime_type($format);
Returns description string for given file format.
my $desc = PDL::IO::Image->format_description($format);
Returns 1 or 0 - module supports (or not) reading given file format.
my $bool = PDL::IO::Image->format_can_read($format);
Returns 1 or 0 - module supports (or not) saving given file format.
my $bool = PDL::IO::Image->format_can_write($format);
Returns 1 or 0 - module can export (or not) given image type to given file format.
my $bool = PDL::IO::Image->format_can_export_type($format, $image_type);
$image_type - string identifying image type (e.g. 'BITMAP' - for valid values see "Supported image types").
Returns 1 or 0 - module can export (or not) given file format in given bits per pixel depth.
my $bool = PDL::IO::Image->format_can_export_bpp($format, $bpp);
$bpp - bits per pixel (e.g. 1, 4, 8, 16, 24, 32)
$bpp
Returns file format string (e.g. 'BMP', 'JPEG' - see "Supported file formats") for given mime type.
my $format = PDL::IO::Image->format_from_mime($mime_type);
Returns file format string (e.g. 'BMP', 'JPEG' - see "Supported file formats") for given $filename.
my $format = PDL::IO::Image->format_from_file($filename);
There many constants which can be used with "new_from_file" or "save" methods. These constants are not exported by this module therefore you have to use full names like this:
use PDL; use PDL::IO::Image; my $pimage = PDL::IO::Image->new_from_file("in.jpg", "JPEG", PDL::IO::Image::JPEG_ACCURATE);
PDL, PDL::IO::Pic, PDL::IO::GD, Alien::FreeImage, http://freeimage.sourceforge.net/
This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
2014+ KMX <kmx@cpan.org>
To install PDL::IO::Image, copy and paste the appropriate command in to your terminal.
cpanm
cpanm PDL::IO::Image
CPAN shell
perl -MCPAN -e shell install PDL::IO::Image
For more information on module installation, please visit the detailed CPAN module installation guide.