 Contents |
| Introduction |
You can try PerlMagick from your Web browser at the ImageMagick Studio. Or, you can see examples of select PerlMagick functions.
| Installation |
ImageMagick must already be installed on your system. Next, get the PerlMagick distribution corresponding to the installed ImageMagick distribution (e.g. PerlMagick 5.29 for ImageMagick 5.2.9) and unpack it as shown below:
gunzip -c PerlMagick-5.29.tar.gz | tar -xvf - cd PerlMagickNext, edit Makefile.PL and change LIBS and INC to include the appropriate path information to the required libMagick library. You will also need paths to JPEG, PNG, TIFF, etc. delegates if they were included with your installed version of ImageMagick. Build and install it like this:
perl Makefile.PL make make installFor Unix, you typically need to be root to install the software. There are ways around this. Consult the Perl manual pages for more information.
Windows NT / Windows 95
ImageMagick must already be installed on your system. Also, the ImageMagick source distribution for Windows 2000 is required. You must also have the nmake from the Visual C++ or J++ development environment. Copy \bin\IMagick.dll and \bin\X11.dll to a directory in your dynamic load path such as c:\perl\site\5.00502. Next, type
cd PerlMagick copy Makefile.nt Makefile.PL perl Makefile.PL nmake nmake installRunning the Regression Tests
To verify a correct installation, type
make testUse nmake test under Windows. There are ao few demonstration scripts available to exercise many of the functions PerlMagick can perform. Type
cd demo makeYou are now ready to utilize the PerlMagick methods from within your Perl scripts.
| Overview |
use Image::Magick; $image=Image::Magick->new;The new method takes the same parameters as SetAttribute. For example,
$image=Image::Magick->new(size=>'384x256');Next you will want to read an image or image sequence, manipulate it, and then display or write it. The input and output methods for PerlMagick are defined in Read or Write an Image. See Set an Image Attribute for methods that affect the way an image is read or written. Refer to Manipulate an Image for a list of methods to transform an image. Get an Image Attribute describes how to retrieve an attribute for an image. Refer to Create an Image Montage for details about tiling your images as thumbnails on a background. Finally, some methods do not neatly fit into any of the categories just mentioned. Review Miscellaneous Methods for a list of these methods.
Once you are finished with a PerlMagick object you should consider destroying it. Each image in an image sequence is stored in virtual memory. This can potentially add up to mega-bytes of memory. Upon destroying a PerlMagick object, the memory is returned for use by other Perl methods. The recommended way to destroy an object is with undef:
undef $image;To delete all the images but retain the Image::Magick object use
@$image = ();and finally, to delete a single image from a multi-image sequence, use
undef $image->[x];The next section illustrates how to use various PerlMagick methods to manipulate an image sequence.
Some of the PerlMagick methods require external programs such as Ghostscript. This may require an explicit path in your PATH environment variable to work properly. For example,
$ENV{PATH}='/bin:/usr/bin:/usr/local/bin';
| Example
Script |
#!/usr/local/bin/perl
use Image::Magick;
my($image, $x);
$image = Image::Magick->new;
$x = $image->Read('girl.png', 'logo.png', 'rose.png');
warn "$x" if "$x";
$x = $image->Crop(geometry=>'100x100"+1"00"+1"00');
warn "$x" if "$x";
$x = $image->Write('x.png');
warn "$x" if "$x";
The script reads three images, crops them, and writes a single image as
a GIF animation sequence. In many cases you may want to access individual
images of a sequence. The next example illustrates how this is done:
#!/usr/local/bin/perl
use Image::Magick;
my($image, $p, $q);
$image = new Image::Magick;
$image->Read('x1.png');
$image->Read('j*.jpg');
$image->Read('k.miff[1, 5, 3]');
$image->Contrast();
for ($x = 0; $image->[x]; $x++)
{
$image->[x]->Frame('100x200') if $image->[x]->Get('magick') eq 'GIF';
undef $image->[x] if $image->[x]->Get('columns') < 100;
}
$p = $image->[1];
$p->Draw(stroke=>'red', primitive=>'rectangle', points=>20,20 100,100');
$q = $p->Montage();
undef $image;
$q->Write('x.miff');
Suppose you want to start out with a 100 by 100 pixel white canvas with
a red pixel in the center. Try
$image = Image::Magick->new;
$image->Set(size=>'100x100');
$image->ReadImage('xc:white');
$image->Set('pixel[49,49]'=>'red');
Or suppose you want to convert your color image to grayscale:
$image->Quantize(colorspace=>'gray');Here we annotate an image with a Taipai TrueType font:
$text = '\0x17ef\0x30ec\0x25ec\0x23ef\0x17ec'; $image->Annotate(font=>'kai.ttf', pointsize=>40, stroke=>'green', text=>$text);Other clever things you can do with a PerlMagick objects include
$i = $#$p"+1"; # return the number of images associated with object p push(@$q, @$p); # push the images from object p onto object q @$p = (); # delete the images but not the object p p->Convolve([1, 2, 1, 2, 4, 2, 1, 2, 1]); # 3x3 Gaussian kernel
| Read
or Write an Image |
| Method | Parameters | Return Value | Description |
|---|---|---|---|
| Read | one or more filenames | the number of images read | read an image or image sequence |
| Write | filename | the number of images written | write an image or image sequence |
| Display | server name | the number of images displayed | display the image or image sequence to an X server |
| Animate | server name | the number of images animated | animate image sequence to an X server |
For convenience, methods Write, Display, and Animate can take any parameter that SetAttribute knows about. For example,
$image->Write(filename=>'image.png', compress=>'None');Use - as the filename to method Read to read from standard in or to method Write to write to standard out:
binmode STDOUT;
$image->Write('png:-');
To read an image in the GIF format from a PERL filehandle, use:
$image = Image::Magick->new(magick=>'GIF'); open(DATA, 'image.png'); $image->Read(file=>DATA); close(DATA);To write an image in the PNG format to a PERL filehandle, use:
$filename = "image.png"; open(DATA, ">$filename"); $image->Write(file=>DATA, filename=>$filename); close(DATA);The % character is always interpreted in output filenames. To get a % character in the filename, use %%.
You can optionally add Image to any method name. For example, ReadImage is an alias for method Read.
| Manipulate
an Image |
$image->Crop(geometry=>'100x100"+1"0+20');
$image->[x]->Frame("100x200");
And here is a list of other image manipulation methods you can call:
| Method | Parameters | Description |
|---|---|---|
| AddNoise | noise=>{Uniform, Gaussian, Multiplicative, Impulse, Laplacian, Poisson} | add noise to an image |
| Annotate | text=>string, font=>string, pointsize=>integer, density=>geometry, stroke=>color name, stroke_width=>integer, fill=>color name, box=>color name, geometry=>geometry, gravity=>{NorthWest, North, NorthEast, West, Center, East, SouthWest, South, SouthEast}, antialias=>{true, false}, x=>integer, y=>integer, translate=>float, float, scale=>float, float, rotate=>float. skewX=>float, skewY=>float | annotate an image with text. See QueryFontMetrics to get font metrics without rendering any text. |
| Blur | geometry=>geometry, radius=>double, sigma=>double | blur the image with a gaussian operator of the given radius and standard deviation (sigma). |
| Border | geometry=>geometry, width=>integer, height=>integer, fill=color name | surround the image with a border of color |
| Channel | channel={Red, Green, Blue, Matte} | extract a channel from the image |
| Charcoal | order=>integer | simulate a charcoal drawing |
| Chop | geometry=>geometry, width=>integer, height=>integer, x=>integer, y=>integer | chop an image |
| Coalesce | merge a sequence of images | |
| ColorFloodfill | geometry=>geometry, x=>integer, y=>integer, fill=color name, bordercolor=color name | changes the color value of any pixel that matches the color of the target pixel and is a neighbor. If you specify a border color, the color value is changed for any neighbor pixel that is not that color. |
| Colorize | color=>color name, fill=>color name | colorize the image with the fill color |
| Comment | string | add a comment to your image |
| Composite | compose=>{Over, In, Out, Atop, Xor, Plus, Minus, Add, Subtract, Difference, Multiply, Bumpmap, Copy, CopyRed, CopyGreen, CopyBlue, CopyMatte, Dissolve, Clear, Displace, Modulate, Threshold}, image=>image-handle, geometry=>geometry, x=>integer, y=>integer, gravity=>{NorthWest, North, NorthEast, West, Center, East, SouthWest, South, SouthEast}, opacity=>integer,tile=>image-handle | composite one image onto another |
| Contrast | sharpen=>{True, False} | enhance or reduce the image contrast |
| Convolve | coefficients=>array of float values | apply a convolution kernel to the image. Given a kernel order, you would supply order*order float values (e.g. 3x3 implies 9 values). |
| Crop | geometry=>geometry, width=>integer, height=>integer, x=>integer, y=>integer | crop an image |
| CycleColormap | amount=>integer | displace image colormap by amount |
| Deconstruct | break down an image sequence into constituent parts | |
| Despeckle | reduce the speckles within an image | |
| Draw | primitive=>{point, line, rectangle, arc, ellipse, circle, polyline, polygon, bezier, color, matte, text, @filename}, points=>string, method={Point, Replace, Floodfill, FillToBorder, Reset}, stroke=>color name, fill=>color name, tile=>image-handle, stroke_width=>float, antialias=>{true, false}, bordercolor=>color name, x=>float, y=>float, translate=>float, float, scale=>float, float, rotate=>float. skewX=>float, skewY=>float | annotate an image with one or more graphic primitives |
| Edge | radius=>double | enhance edges within the image with a convolution filter of the given radius. |
| Emboss | geometry=>geometry, radius=>double, sigma=>double | emboss the image with a convolution filter of the given radius and standard deviation (sigma). |
| Enhance | apply a digital filter to enhance a noisy image | |
| Equalize | perform histogram equalization to the image | |
| Flip | create a mirror image by reflecting the image scanlines in the vertical direction | |
| Flop | create a mirror image by reflecting the image scanlines in the horizontal direction | |
| Frame | geometry=>geometry, width=>integer, height=>integer, inner=>integer, outer=>integer, fill=>color name | surround the image with an ornamental border |
| Gamma | gamma=>double, red=>double, green=>double, blue=>double | gamma correct the image |
| Implode | factor=>percentage | implode image pixels about the center |
| Label | string | assign a label to an image |
| Magnify | double the size of an image | |
| Map | image=>image-handle, dither={True, False} | choose a particular set of colors from this image |
| MatteFloodfill | geometry=>geometry, x=>integer, y=>integer, matte=integer, bordercolor=color name | changes the matte value of any pixel that matches the color of the target pixel and is a neighbor. If you specify a border color, the matte value is changed for any neighbor pixel that is not that color. |
| MedianFilter | radius=>double | replace each pixel with the median intensity pixel of a neighborhood. |
| Minify | half the size of an image | |
| Modulate | brightness=>double, saturation=>double, hue=>double | vary the brightness, saturation, and hue of an image by the specified percentage |
| MotionBlur | geometry=>geometry, radius=>double, sigma=>double, angle=>double | blur the image with a gaussian operator of the given radius and standard deviation (sigma) at the given angle to simulate the effect of motion |
| Border | ||
| Negate | gray=>{True, False} | replace every pixel with its complementary color (white becomes black, yellow becomes blue, etc.) |
| Normalize | transform image to span the full range of color values | |
| OilPaint | radius=>integer | simulate an oil painting |
| Opaque | color=>color name, fill=>color name | change this color to the fill color within the image |
| Quantize | colors=>integer, colorspace=>{RGB, Gray, Transparent, OHTA, XYZ, YCbCr, YIQ, YPbPr, YUV, CMYK}, treedepth=> integer, dither=>{True, False}, measure_error=>{True, False}, global_colormap=>{True, False} | preferred number of colors in the image |
| Profile | filename=>filename, profile=>{ICM, IPTC} | add or remove ICC or IPTC image profile |
| Raise | geometry=>geometry, width=>integer, height=>integer, x=>integer, y=>integer, raise=>{True, False} | lighten or darken image edges to create a 3-D effect |
| ReduceNoise | radius=>double | reduce noise in the image with a noise peak elimination filter |
| Resize | geometry=>geometry, width=>integer, height=>integer, filter=>{Point, Box, Triangle, Hermite, Hanning, Hamming, Blackman, Gaussian, Quadratic, Cubic, Catrom, Mitchell, Lanczos, Bessel, Sinc}, blur=>double | scale image to desired size. Specify blur > 1 for blurry or < 1 for sharp |
| Roll | geometry=>geometry, x=>integer, y=>integer | roll an image vertically or horizontally |
| Rotate | degrees=>double, crop=>{True, False}, sharpen=>{True, False} | roll an image vertically or horizontally |
| Sample | geometry=>geometry, width=>integer, height=>integer | scale image with pixel sampling |
| Scale | geometry=>geometry, width=>integer, height=>integer | scale image to desired size |
| Segment | colorspace=>{RGB, Gray, Transparent, OHTA, XYZ, YCbCr, YCC, YIQ, YPbPr, YUV, CMYK}, verbose={True, False}, cluster=>double, smooth=double | segment an image by analyzing the histograms of the color components and identifying units that are homogeneous |
| Shade | geometry=>geometry, azimuth=>double, elevation=>double, color=>{true, false} | shade the image using a distant light source |
| Sharpen | geometry=>geometry, radius=>double, sigma=>double | sharpen the image with a gaussian operator of the given radius and standard deviation (sigma). |
| Shear | geometry=>geometry, x=>double, y=>double, crop=>{true, false} | shear the image along the X or Y axis by a positive or negative shear angle |
| Signature | generate an MD5 signature for the image | |
| Solarize | factor=>percentage | negate all pixels above the threshold level |
| Spread | amount=>integer | displace image pixels by a random amount |
| Stereo | image=>image-handle | combines two images and produces a single image that is the composite of a left and right image of a stereo pair |
| Stegano | image=>image-handle, offset=integer | hide a digital watermark within the image |
| Swirl | degrees=>double | swirl image pixels about the center |
| Texture | texture=>image-handle | name of texture to tile onto the image background |
| Threshold | threshold=>integer | threshold the image |
| Transparent | color=>color name | make this color transparent within the image |
| Trim | remove edges that are the background color from the image | |
| UnsharpMask | geometry=>geometry, radius=>double, sigma=>double, amount=>double, threshold=>double | sharpen the image with the unsharp mask algorithm. |
| Wave | geometry=>geometry, amplitude=>double, wavelength=>double | alter an image along a sine wave |
Note, that the geometry parameter is a short cut for the width and height parameters (e.g. geometry=>'106x80' is equivalent to width=>106, height=>80).
You can specify @filename in both Annotate and Draw. This reads the text or graphic primitive instructions from a file on disk. For example,
$image->Draw(pen=>'red', primitive=>'rectangle', points=>'20,20 100,100 40,40 200,200 60,60 300,300');Is eqivalent to
$image->Draw(pen=>'red', primitive=>'@draw.txt');Where draw.txt is a file on disk that contains this:
rectangle 20, 20 100, 100 rectangle 40, 40 200, 200 rectangle 60, 60 300, 300The text parameter for methods, Annotate, Comment, Draw, and Label can include the image filename, type, width, height, or other image attribute by embedding these special format characters:
%b file size %d comment %d directory %e filename extension %f filename %h height %m magick %p page number %s scene number %t top of filename %w width %x x resolution %y y resolution \n newline \r carriage returnFor example,
text=>"%m:%f %wx%h"
You can optionally add Image to any method name. For example, TrimImage is an alias for method Trim.
Most of the attributes listed above have an analog in convert. See the documentation for a more detailed description of these attributes.
| Set
an Image Attribute |
$image->Set(dither=>'True'); $image->[$x]->Set(delay=>3);And here is a list of all the image attributes you can set:
| Attribute | Values | Description |
|---|---|---|
| adjoin | {True, False} | join images into a single multi-image file |
| antialias | {True, False} | remove pixel aliasing |
| background | color name | image background color |
| blue-primary | x-value, y-value | chromaticity blue primary point (e.g. 0.15, 0.06) |
| bordercolor | color name | set the image border color |
| cache-threshold | integer | Image pixels are stored in memory until your computers real memory has been consumed. Subsequent pixel operations are cached on disk. Operations to memory are significantly faster but if your computer does not have a sufficient amount of free memory you may want to set this threshold to a small megabyte value. Use 0 to cache all images to disk. |
| colormap[i] | color name | color name (e.g. red) or hex value (e.g. #ccc) at position i |
| colorspace | {RGB, CMYK} | type of colorspace |
| compress | None, BZip, Fax, Group4, JPEG, LosslessJPEG, LZW, Runlength, Zip | type of image compression |
| delay | integer | this many 1/100ths of a second\fP must expire before displaying the next image in a sequence |
| density | geometry | vertical and horizontal resolution in pixels of the image |
| dispose | {0, 1, 2, 3} | GIF disposal method |
| dither | {True, False} | apply error diffusion to the image |
| display | string | specifies the X server to contact |
| file | filehandle | set the image filehandle |
| filename | string | set the image filename |
| font | string | use this font when annotating the image with text |
| fuzz | integer | colors within this distance are considered equal |
| green-primary | x-value, y-value | chromaticity green primary point (e.g. 0.3, 0.6) |
| index[x, y] | string | colormap index at position (x, y) |
| interlace | {None, Line, Plane, Partition} | the type of interlacing scheme |
| iterations | integer | add Netscape loop extension to your GIF animation |
| loop | integer | add Netscape loop extension to your GIF animation |
| magick | string | set the image format |
| matte | {True, False} | True if the image has transparency |
| mattecolor | color name | set the image matte color |
| monochrome | {True, False} | transform the image to black and white |
| page | { Letter, Tabloid, Ledger, Legal, Statement, Executive, A3, A4, A5, B4, B5, Folio, Quarto, 10x14} or geometry | preferred size and location of an image canvas |
| pixel[x, y] | string | hex value (e.g. #ccc) at position (x, y) |
| pointsize | integer | pointsize of the Postscript or TrueType font |
| preview | { Rotate, Shear, Roll, Hue, Saturation, Brightness, Gamma, Spiff, Dull, Grayscale, Quantize, Despeckle, ReduceNoise, AddNoise, Sharpen, Blur, Threshold, EdgeDetect, Spread, Solarize, Shade, Raise, Segment, Swirl, Implode, Wave, OilPaint, CharcoalDrawing, JPEG} | type of preview for the Preview image format |
| quality | integer | JPEG/MIFF/PNG compression level |
| red-primary | x-value, y-value | chromaticity red primary point (e.g. 0.64, 0.33) |
| rendering-intent | {Undefined, Saturation, Perceptual, Absolute, Relative} | the type of rendering intent |
| scene | integer | image scene number |
| subimage | integer | subimage of an image sequence |
| subrange | integer | number of images relative to the base image |
| server | string | specifies the X server to contact |
| size | string | width and height of a raw image |
| tile | string | tile name |
| texture | string | name of texture to tile onto the image background |
| type | {Bilevel, Grayscale, Palette, PaletteMatte, TrueColor, TrueColorMatte, ColorSeparation } | image type |
| units | { Undefined, PixelsPerInch, PixelsPerCentimeters} | units of image resolution |
| verbose | {True, False} | print detailed information about the image |
| white-point | x-value, y-value | chromaticity white point (e.g. 0.3127, 0.329) |
Note, that the geometry parameter is a short cut for the width and height parameters (e.g. geometry=>'106x80' is equivalent to width=>106, height=>80).
SetAttribute is an alias for method Set.
Most of the attributes listed above have an analog in convert. See the documentation for a more detailed description of these attributes.
| Get
an Image Attribute |
($a, $b, $c) = $image->Get('colorspace', 'magick', 'adjoin');
$width = $image->[3]->Get('columns');
In addition to all the attributes listed in Set an Image
Attribute, you can get these additional attributes:
| Attribute | Values | Description |
|---|---|---|
| base-columns | integer | base image width (before transformations) |
| base-filename | string | base image filename (before transformations) |
| base-rows | integer | base image height (before transformations) |
| class | {Direct, Pseudo} | image class |
| colors | integer | number of unique colors in the image |
| comment | string | image comment |
| columns | integer | image width |
| depth | integer | image depth |
| directory | string | tile names from within an image montage |
| error | double | the mean error per pixel computed when an image is color reduced |
| filesize | integer | number of bytes of the image on disk |
| format | string | get the descriptive image format |
| gamma | double | gamma level of the image |
| geometry | string | image geometry |
| height | integer | the number of rows or height of an image |
| label | string | image label |
| maximum-error | double | the normalized max error per pixel computed when an image is color reduced |
| mean-error | double | the normalized mean error per pixel computed when an image is color reduced |
| montage | geometry | tile size and offset within an image montage |
| rows | integer | the number of rows or height of an image |
| signature | string | MD5 signature associated with the image |
| taint | {True, False} | True if the image has been modified |
| width | integer | the number of columns or width of an image |
| x-resolution | integer | x resolution of the image |
| y-resolution | integer | y resolution of the image |
GetAttribute is an alias for method Get.
Most of the attributes listed above have an analog in convert. See the documentation for a more detailed description of these attributes.
| Create
an Image Montage |
$image->Montage(geometry=>'160x160', tile=>'2x2', texture=>'granite:');And here is a list of Montage parameters you can set:
| Parameter | Values | Description |
|---|---|---|
| background | color name | background color name |
| borderwidth | integer | image border width |
| compose | {Over, In, Out, Atop, Xor, Plus, Minus, Add, Subtract, Difference, Bumpmap, Copy, Mask, Dissolve, Clear, Displace} | composite operator |
| filename | string | name of montage image |
| fill | color name | fill color for annotations |
| font | string | X11 font name |
| frame | geometry | surround the image with an ornamental border |
| geometry | geometry | preferred tile and border size of each tile of the composite image |
| gravity | {NorthWest, North, NorthEast, West, Center, East, SouthWest, South, SouthEast} | direction image gravitates to within a tile |
| label | string | assign a label to an image |
| mode | {Frame, Unframe, Concatenate} | thumbnail framing options |
| pointsize | integer | pointsize of the Postscript or TrueType font |
| shadow | {True, False} | add a shadow beneath a tile to simulate depth |
| stroke | color name | stroke color for annotations |
| texture | string | name of texture to tile onto the image background |
| tile | geometry | number of tiles per row and column |
| title | string | assign a title to the image montage |
| transparent | string | make this color transparent within the image |
Note, that the geometry parameter is a short cut for the width and height parameters (e.g. geometry=>'106x80' is equivalent to width=>106, height=>80).
MontageImage is an alias for method Montage.
Most of the attributes listed above have an analog in montage. See the documentation for a more detailed description of these attributes.
| Working
with Blobs |
| Method | Parameters | Return Value | Description |
|---|---|---|---|
| ImageToBlob | any image attribute | an array of image data in the respective image format | convert an image or image sequence to an array of blobs |
| BlobToImage | one or more blobs | the number of blobs converted to an image | convert one or more blobs to an image |
ImageToBlob returns the image data in their respective formats. You can then print it, save it to an ODBC database, write it to a file, or pipe it to a display program:
@blobs = $image->ImageToBlob(); open(DISPLAY,"| display -") || die; binmode DISPLAY; print DISPLAY $blobs[0]; close DISPLAY;Method BlobToImage returns an image or image sequence converted from the supplied blob:
$blob=$db->GetImage(); $image=Image::Magick->new(magick=>'jpg'); $image->BlobToImage($blob);
| Miscellaneous
Methods |
$p = $image->Append(stack=>{true,false});
appends all the images associated with object $image. All the
input images must have the same width or height. Images of the same width
are stacked top-to-bottom. Images of the same height are stacked left-to-right.
If the stack parameter is false, rectangular images are stacked left-to-right
otherwise top-to-bottom.
The Average method averages a set of images. For example,
$p = $image->Average();averages all the images associated with object $image.
The Clone method copies a set of images. For example,
$p = $image->Clone();copies all the images from object $q to $p. You can use this method for single or multi-image sequences.
The Morph method morphs a set of images. Both the image pixels and size are linearly interpolated to give the appearance of a meta-morphosis from one image to the next:
$p = $image->Morph(frames=>integer);where frames is the number of in-between images to generate. The default is 1.
Mosaic creates an mosaic from an image sequence.
Method Mogrify is a single entry point for the image manipulation methods (Manipulate an Image). The parameters are the name of a method followed by any parameters the method may require. For example, these calls are equivalent:
$image->Crop('340x256+0+0');
$image->Mogrify('crop', '340x256+0+0');
Method MogrifyRegion applies a transform to a region of the image.
It is similiar to Mogrify but begins with the region geometry.
For example, suppose you want to brighten a 100x100 region of your image
at location (40, 50):
$image->MogrifyRegion('100x100+40+50', 'modulate', brightness=>50);
($width, $height, $size, $format) = split(',', $image->Ping('logo.png'));
This is a more efficient and less memory intensive way to query if an image
exists and what its characteristics are. Note, only information about the
first image in a multi-frame image file is returned.
To have full control over text positioning you will need font metric information. Use
($x_ppem, $y_ppem, $ascender, $descender, $width, $height, $max_advance) =
split(', ', $image->QueryFontMetrics(parameters));
Where parameters is any parameter of the Annotate
method. The return values are
($red, $green, $blue, $opacity) = split(', ', $image->QueryColor('cyan'));
($red, $green, $blue, $opacity) = split(', ', $image->QueryColor('#716bae'));
$name = $image->QueryColorName('rgba(80,60,0,0)');
Use RemoteCommand to send a command to an already running display
or animate application. The only parameter is
the name of the image file to display or animate.
Finally, the Transform method accepts a fully-qualified geometry specification for cropping or resizing one or more images. For example,
$p = $image->Transform(crop=>'100x100');You can optionally add Image to any method name above. For example, PingImage is an alias for method Ping.
| Handling
Errors |
$x = $image->Read(...); warn "$x" if "$x"; # print the error message $x =~ /(\d+)/; print $1; # print the error number print 0+$x; # print the number of images read
$x = $image->Crop(...); warn "$x" if "$x"; # print the error message $x =~ /(\d+)/; print $1; # print the error number
$x = $image->Montage(...); warn "$x" if !ref($x); # print the error message $x =~ /(\d+)/; print $1; # print the error numberHere is an example error message:
Error 400: Memory allocation failedBelow is a list of error and warning codes:
| Code | Mnemonic | Description |
|---|---|---|
| 0 | Success | method completed without an error or warning |
| 300 | ResourceLimitWarning | a program resource is exhausted (e.g. not enough memory) |
| 305 | XServerWarning | an X resource is unavailable |
| 310 | OptionWarning | a command-line option was malformed |
| 315 | DelegateWarning | an ImageMagick delegate returned a warning |
| 320 | MissingDelegateWarning | the image type can not be read or written because the appropriate Delegate is missing |
| 325 | CorruptImageWarning | the image file may be corrupt |
| 330 | FileOpenWarning | the image file could not be opened |
| 335 | BlobWarning | a binary large object could not be allocated |
| 340 | CacheWarning | pixels could not be saved to the pixel cache |
| 400 | ResourceLimitError | a program resource is exhausted (e.g. not enough memory) |
| 405 | XServerError | an X resource is unavailable |
| 410 | OptionError | a command-line option was malformed |
| 415 | DelegateError | an ImageMagick delegate returned a warning |
| 420 | MissingDelegateError | the image type can not be read or written because the appropriate Delegate is missing |
| 425 | CorruptImageError | the image file may be corrupt |
| 430 | FileOpenError | the image file could not be opened |
| 435 | BlobError | a binary large object could not be allocated |
| 440 | CacheError | pixels could not be saved to the pixel cache |
The following illustrates how you can use a numeric status code:
$x = $image->Read('rose.png');
$x =~ /(\d+)/;
die "unable to continue" if ($1 == ResourceLimitError);
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Image manipulation software that works like magic.