`Pixmap`¶

A Pixmap object contains a color raster image (short for pixel map). The components in a pixel in the Pixmap are all byte values, with the transparency as the last component. A Pixmap also has a location (x, y) in addition to its size; so that they can easily be used to represent tiles of a page.

new Pixmap(colorspace, bounds, alpha)¶

Constructor method.

Create a new pixmap. The pixel data is not initialized; and will contain garbage.

Arguments:

colorspace – ColorSpace.
bounds – [ulx,uly,lrx,lry] Rectangle.
alpha – Boolean.

Returns:

Pixmap.

EXAMPLE

var pixmap = new mupdf.Pixmap(mupdf.ColorSpace.DeviceRGB, [0,0,100,100], true);

Instance methods

clear(value)¶

Clear the pixels to the specified value. Pass 255 for white, or omit for transparent.

Arguments:

value – Pixel value.

EXAMPLE

pixmap.clear(255);
pixmap.clear();

getBounds()¶

Return the pixmap bounds.

Returns:: [ulx,uly,lrx,lry] Rectangle.

EXAMPLE

var rect = pixmap.getBounds();

getWidth()¶

Returns:: Int The width value.

EXAMPLE

var w = pixmap.getWidth();

getHeight()¶

Returns:: Int The height value.

EXAMPLE

var h = pixmap.getHeight();

getNumberOfComponents()¶

Number of colors; plus one if an alpha channel is present.

Returns:: Int Number of color components.

EXAMPLE

var num = pixmap.getNumberOfComponents();

getAlpha()¶

True if alpha channel is present.

Returns:: Boolean.

EXAMPLE

var alpha = pixmap.getAlpha();

getStride()¶

Number of bytes per row.

Returns:: Int.

EXAMPLE

var stride = pixmap.getStride();

getColorSpace()¶

Returns the ColorSpace for the Pixmap.

Returns:: ColorSpace.

EXAMPLE

var cs = pixmap.getColorSpace();

setResolution(xRes, yRes)¶

Set x & y resolution.

Arguments:

xRes – Int X resolution in dots per inch.
yRes – Int Y resolution in dots per inch.

EXAMPLE

pixmap.setResolution(300, 300);

getXResolution()¶

Returns the x resolution for the Pixmap.

Returns:: Int Resolution in dots per inch.

EXAMPLE

var xRes = pixmap.getXResolution();

getYResolution()¶

Returns the y resolution for the Pixmap.

Returns:: Int Resolution in dots per inch.

EXAMPLE

var yRes = pixmap.getYResolution();

getSample(x, y, index)¶

mutool only

Get the value of component index at position x, y (relative to the image origin: 0, 0 is the top left pixel).

Arguments:

x – X co-ordinate.
y – Y co-ordinate.
index – Component index. i.e. For CMYK ColorSpaces 0 = Cyan, for RGB 0 = Red etc.

Returns:

Int.

EXAMPLE

var sample = pixmap.getSample(0,0,0);

saveAsPNG(fileName)¶

mutool only

Save the Pixmap as a PNG. Only works for Gray and RGB images.

Arguments:

fileName – String.

EXAMPLE

pixmap.saveAsPNG("fileName.png");

saveAsJPEG(fileName, quality)¶

mutool only

Save the Pixmap as a JPEG. Only works for Gray, RGB and CMYK images.

Arguments:

fileName – String.
quality – Int.

EXAMPLE

pixmap.saveAsJPEG("fileName.jpg", 80);

saveAsPAM(fileName)¶

mutool only

Save the Pixmap as a PAM.

Arguments:

fileName – String.

EXAMPLE

pixmap.saveAsPAM("fileName.pam");

saveAsPNM(fileName)¶

mutool only

Save the Pixmap as a PNM. Only works for Gray and RGB images without alpha.

Arguments:

fileName – String.

EXAMPLE

pixmap.saveAsPNM("fileName.pnm");

saveAsPBM(fileName)¶

mutool only

Save the Pixmap as a PBM. Only works for Gray and RGB images without alpha.

Arguments:

fileName – String.

EXAMPLE

pixmap.saveAsPBM("fileName.pbm");

saveAsPKM(fileName)¶

mutool only

Save the Pixmap as a PKM. Only works for Gray and RGB images without alpha.

Arguments:

fileName – String.

EXAMPLE

pixmap.saveAsPKM("fileName.pkm");

invert()¶

Invert all pixels. All components are processed, except alpha which is unchanged.

EXAMPLE

pixmap.invert();

invertLuminance()¶

Transform all pixels so that luminance of each pixel is inverted, and the chrominance remains as unchanged as possible. All components are processed, except alpha which is unchanged.

EXAMPLE

pixmap.invertLuminance();

gamma(gamma)¶

Apply gamma correction to Pixmap. All components are processed, except alpha which is unchanged.

Values >= 0.1 & < 1 = darken, > 1 & < 10 = lighten.

Arguments:

gamma – Float.

EXAMPLE

pixmap.gamma(3);

tint(black, white)¶

Tint all pixels in a RGB, BGR or Gray Pixmap.: Map black and white respectively to the given hex RGB values.

Arguments:

black – Integer.
white – Integer.

EXAMPLE

pixmap.tint(0xffff00, 0xffff00);

warp(points, width, height)¶

Return a warped subsection of the Pixmap, where the result has the requested dimensions.

Arguments:

points – [x0, y0, x1, y1, x2, y2, x3, y3, x4, y4]

Points give the corner points of a convex quadrilateral within the Pixmap to be warped. :arg width: Int. :arg height: Int.

Returns:: Pixmap.

EXAMPLE

var warpedPixmap = pixmap.warp([0,0,100,0,0,100,100,100],200,200);

convertToColorSpace(colorspace, proof, defaultColorSpaces, colorParams, keepAlpha)¶

Convert pixmap into a new pixmap of a desired colorspace. A proofing colorspace, a set of default colorspaces and color parameters used during conversion may be specified. Finally a boolean indicates if alpha should be preserved (default is to not preserve alpha).

Arguments:

colorspace – Colorspace.
proof – Colorspace.
defaultColorSpaces – DefaultColorSpaces.
colorParams – [].
keepAlpha – Boolean.

Returns:

Pixmap.

getPixels()¶

wasm only

Returns an array of pixels for the Pixmap.

Returns:: [...].

EXAMPLE

var pixels = pixmap.getPixels();

asPNG()¶

wasm only

Returns a buffer of the Pixmap as a PNG.

Returns:: Buffer.

EXAMPLE

var buffer = pixmap.asPNG();

asPSD()¶

wasm only

Returns a buffer of the Pixmap as a PSD.

Returns:: Buffer.

EXAMPLE

var buffer = pixmap.asPSD();

asPAM()¶

wasm only

Returns a buffer of the Pixmap as a PAM.

Returns:: Buffer.

EXAMPLE

var buffer = pixmap.asPAM();

asJPEG(quality)¶

wasm only

Returns a buffer of the Pixmap as a JPEG. Note, if the Pixmap has an alpha channel then an exception will be thrown.

Returns:: Buffer.

EXAMPLE

var buffer = pixmap.asJPEG(80);

skewDetect()¶

wasm only

Returns the angle of skew detected from Pixmap. Note, if the Pixmap is not Greyscale with no alpha then an exception will be thrown.

Returns:: Float.

EXAMPLE

var angle = pixmap.skewDetect();

deskew(angle, border)¶

wasm only

Returns a new Pixmap being the deskewed version of the supplied Pixmap. Note, if a Pixmap is supplied that is not RGB or Greyscale, or has alpha then an exception will be thrown.

Arguments:

angle – Float. The angle to deskew.
border – String. “increase” increases the size of the pixmap so no pixels are lost. “maintain” maintains the size of the pixmap. “decrease” decreases the size of the page so no new pixels are shown.

Returns:

Pixmap.

EXAMPLE

var deskewed = pixmap.deskew(angle, 0);

Pixmap¶

`Pixmap`¶