Download the PHP package rkr/image without Composer

php-image-manipulation

A simple image manipulation library using gd-lib

Installation

Usage (PHP 8.1+)

More information is also available in the generated docs.

Resample proportionally

Enlarge canvas

Auto crop image with optional border

The crop function is solved via a separate algorithm. If a border width is specified as a percentage, but too much of the original graphic was cut away during the actual cropping, then this image portion is retained in the border area.

Text rendering (TrueType)

Requires GD with FreeType support and a .ttf/.otf font file.

Image API reference (all methods)

All methods throw Kir\Image\ImageRuntimeException on invalid input / unsupported operations.

Static methods

• public static function getImageType(string $filename): int
  Detects the image type constant (e.g. IMAGETYPE_PNG) for a file.
• public static function getDefaultImageExtension(string $filename): ?string
  Returns a default extension (e.g. "png") detected via mime_content_type.
• public static function supportsFormat(int|string $format, bool $forWriting = false): bool: Checks runtime read support by IMAGETYPE_* or extension; set $forWriting for the library’s output formats.
• public static function getSupportedFormats(bool $forWriting = false): array: Returns canonical names for the formats supported by the current GD build and this library.
• public static function loadFromString(string $data): Image
  Loads an image from raw bytes.
• public static function loadFromFile(string $filename): Image
  Loads AVIF, BMP, GIF, JPEG, PNG, WBMP, WebP, XBM, XPM, TGA, GD and GD2 images from a file path. Optional formats must be enabled in the installed GD build.
• public static function create(int $width, int $height, ?Color $color = null, ?int $imageType = null): Image
  Creates a new blank image (defaults to a transparent white background).

Object lifecycle

• public function __construct(\GdImage $resource, ?int $type = null)
  Wraps an existing GD image object (prefer loadFromFile() / create() if possible).

Basic information

• public function getGdImage(): \GdImage
  Returns the underlying GD image.
• public function getWidth(): int
  Returns the image width in pixels.
• public function getHeight(): int
  Returns the image height in pixels.
• public function getFileType(): ?int
  Returns the last known IMAGETYPE_* (if available).
• public function getMimeType(): ?string
  Returns a MIME type like "image/png" if the file type is known.
• public function getCopy(): self
  Creates a full copy of the image.

Compositing / paste

• public function placeImageOn(Image|\GdImage $targetImage, int $offsetX = 0, int $offsetY = 0): self
  Deprecated alias for pasteOn().
• public function pasteOn(Image|\GdImage $targetImage, int $offsetX = 0, int $offsetY = 0): self
  Copies this image onto the given target.

Pixel inspection

• public function getRedColorAt(int $x, int $y): int
• public function getGreenColorAt(int $x, int $y): int
• public function getBlueColorAt(int $x, int $y): int
• public function getAlphaAt(int $x, int $y): int
  Returns alpha in 0..255 (0 transparent, 255 opaque).
• public function getChannelColorAt(int $x, int $y, int $bitMask): int
  Low-level helper used by the channel getters.

Filters / color operations

• public function greyscale(): self
  Applies IMG_FILTER_GRAYSCALE.
• public function applyAlphaMaskFromGreyscaleImage(Image $mask): self
  Uses a same-sized greyscale mask’s channel value as alpha for the current image.
• public function adjustColors(): self
  Stretches colors to fill the full 0..255 range; constant-color images remain unchanged.

Geometric transformations

• public function rotate(float $angle, ?Color $backgroundColor = null): self: Rotates anticlockwise, expands the canvas and uses transparent white for uncovered areas by default.
• public function flip(int $mode = IMG_FLIP_HORIZONTAL): self: Flips using IMG_FLIP_HORIZONTAL, IMG_FLIP_VERTICAL or IMG_FLIP_BOTH.

Auto-crop / content detection

• public function crop(int $threshold = 15, int $borderPercent = 0, ?Color $backgroundColor = null): self
  Removes excess whitespace around the detected inner object and optionally adds a border.
• public function detectInnerObject(int $threshold = 15): array
  Returns measures: left, top, right, bottom, width, height.

Canvas resizing (crop/pad)

• public function resizeCanvas(int $width, int $height, ?int $offsetX = null, ?int $offsetY = null, ?Color $backgroundColor = null): self
  Changes canvas size; crops or pads with background color (offset defaults to centered).
• public function resizeCanvasCentered(int $width, int $height, ?Color $backgroundColor = null): self
  Centered convenience wrapper for resizeCanvas().

Resampling / proportional resizing

• public function resize(?int $width = null, ?int $height = null): self
  Resamples to exact size (non-proportional); omitted dimensions keep current size.
• public function cropToCover(int $width, int $height): self: Resamples and center-crops to cover the exact target dimensions.
• public function shrinkProportional(?int $width = null, ?int $height = null): self
  Only shrinks if the image is larger than the target rectangle.
• public function resizeProportional(?int $width = null, ?int $height = null): self
  Resizes proportionally to fit inside the target rectangle.
• public function enlargeProportional(?int $width = null, ?int $height = null): self
  Resizes proportionally aiming to enlarge to the target rectangle.

Drawing

• public function fill(int $x, int $y, Color $color): self
  Flood-fill starting at the given pixel.
• public function rectangle(int $x, int $y, int $width, int $height, Color $color): self
  Draws a filled rectangle.

Text rendering (TrueType)

Requires GD with FreeType support.

• public function measureText(string $text, string $fontFile, float $fontSize, float $angle = 0.0): array
  Returns width, height, offsetX, offsetY and the raw bbox array (from imagettfbbox()).
• public function text(string $text, int $x, int $y, string $fontFile, float $fontSize, Color $color, float $angle = 0.0, string $anchor = 'top-left'): self
  Draws TTF text; anchors include top-left, center, bottom-right, baseline-left, etc.

Alpha/background

• public function removeAlphaBackground(?Color $color = null): self
  Replaces transparency with an opaque background color (default: white).

Saving / output

• public function saveAs(?string $filename, ?int $explicitType = null): self
  Saves based on extension (or forced type) and defaults to the last known file type.
• public function saveAsPng(?string $filename = null): self
• public function saveAsJpeg(?string $filename = null, int $quality = 100): self
• public function saveAsGif(?string $filename = null): self
• public function saveAsWebP(?string $filename = null, int $quality = 100): self
• public function saveAsBmp(?string $filename = null): self
• public function saveAsString(?int $imageType = null, int $quality = 100): string
  Encodes the image into bytes (useful for HTTP responses or storage).

Internal helpers (private, not part of the public API)

• private static function temporaryRemoveAlphaChannel(Image $srcIm, \Closure $fn): void
  Used by JPEG/GIF/BMP saving to replace alpha with an opaque background.
• private static function createResource(int $width, int $height, ?Color $color = null): \GdImage
  Creates a new \GdImage and initializes alpha handling.
• private static function createGdColorFromColor(\GdImage $resource, Color $color): int
  Converts Color into a GD color index for the given image resource.