curioustorvald/tsvm
1
0
Fork 0
mirror of https://github.com/curioustorvald/tsvm.git synced 2026-03-11 05:31:51 +09:00
Code Issues Packages Projects Releases Wiki Activity

improved XYB conversion

Browse Source
This commit is contained in:
minjaesong
2025-08-27 01:37:43 +09:00
parent 33e77e378e
commit cda9a34b23
4 changed files with 40 additions and 18 deletions
Download Patch File Download Diff File Expand all files Collapse all files

25
tsvm_core/src/net/torvald/tsvm/GraphicsJSR223Delegate.kt
View File

@@ -1656,10 +1656,13 @@ class GraphicsJSR223Delegate(private val vm: VM) {
val x = xBlock[xbIdx]
val b = bBlock[xbIdx]
// Dequantize from integer ranges
val yVal = (y - 128.0) / 255.0
val xVal = x / 255.0
val bVal = b / 255.0
// Optimal range-based dequantization (exact inverse of improved quantization)
val X_MIN = -0.016; val X_MAX = 0.030
val xVal = (x / 255.0) * (X_MAX - X_MIN) + X_MIN // X: inverse of range mapping
val Y_MAX = 0.85
val yVal = (y / 255.0) * Y_MAX // Y: inverse of improved scale
val B_MAX = 0.85
val bVal = (((b - 1.0) + 128.0) / 255.0) * B_MAX // B: inverse of ((val/B_MAX*255)-128+1)
// XYB to LMS gamma
val lgamma = xVal + yVal
@@ -1723,10 +1726,16 @@ class GraphicsJSR223Delegate(private val vm: VM) {
val yVal = (lgamma + mgamma) / 2.0
val bVal = sgamma
// Quantize to integer ranges suitable for TEV
val yQuant = (yVal * 255.0 + 128.0).toInt().coerceIn(0, 255) // Y: 0-255 (like YCoCg Y)
val xQuant = (xVal * 255.0).toInt().coerceIn(-128, 127) // X: -128 to +127 (like Co)
val bQuant = (bVal * 255.0).toInt().coerceIn(-128, 127) // B: -128 to +127 (like Cg, aggressively quantized)
// Optimal range-based quantization for XYB values (improved precision)
// X: actual range -0.016 to +0.030, map to full 0-255 precision
val X_MIN = -0.016; val X_MAX = 0.030
val xQuant = (((xVal - X_MIN) / (X_MAX - X_MIN)) * 255.0).toInt().coerceIn(0, 255)
// Y: range 0 to 0.85, map to 0 to 255 (improved scale)
val Y_MAX = 0.85
val yQuant = ((yVal / Y_MAX) * 255.0).toInt().coerceIn(0, 255)
// B: range 0 to 0.85, map to -128 to +127 (improved precision with +1 offset for yellow-green)
val B_MAX = 0.85
val bQuant = (((bVal / B_MAX) * 255.0) - 128.0 + 1.0).toInt().coerceIn(-128, 127)
// Store XYB values
val yIdx = py * 16 + px