PixelMap

Result of a pixel read operation. This contains the ImageBitmap pixel information represented as a 1 dimensional array of values that supports queries of pixel values based on the 2 dimensional coordinates of the corresponding ImageBitmap this was obtained from

import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.ImageBitmap
import androidx.compose.ui.graphics.PixelMap

val imageBitmap = createImageBitmap()

val buffer = IntArray(20 * 10)
imageBitmap.readPixels(buffer = buffer, startX = 8, startY = 9, width = 20, height = 10)

val pixelmap = PixelMap(buffer = buffer, width = 20, height = 10, stride = 20, bufferOffset = 0)

// create a histogram to count the number of occurrences of a color within the specified
// subsection of the provided ImageBitmap
val histogram = HashMap<Color, Int>()
for (x in 0 until pixelmap.width) {
    for (y in 0 until pixelmap.height) {
        val color = pixelmap[x, y]
        val colorCount = histogram[color] ?: 0
        histogram[color] = (colorCount + 1)
    }
}

Summary

PixelMap(
    buffer: IntArray,
    width: Int,
    height: Int,
    bufferOffset: Int,
    stride: Int
)

operator fun get(x: @IntRange(from = 0) Int, y: @IntRange(from = 0) Int): Color

val buffer: IntArray

val bufferOffset: Int

val height: Int

val stride: Int

val width: Int