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Support for many many LUT source on C level

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Alexander 2018-04-14 23:12:28 +03:00
parent 63b243e1f6
commit 2c87242027
2 changed files with 44 additions and 8 deletions
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51
src/_imaging.c
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@ -356,6 +356,7 @@ getbands(const char* mode)
#define TYPE_UINT8 (0x100|sizeof(UINT8))
#define TYPE_INT32 (0x200|sizeof(INT32))
#define TYPE_FLOAT16 (0x500|sizeof(FLOAT16))
#define TYPE_FLOAT32 (0x300|sizeof(FLOAT32))
#define TYPE_DOUBLE (0x400|sizeof(double))
@ -439,6 +440,28 @@ getlist(PyObject* arg, Py_ssize_t* length, const char* wrong_length, int type)
return list;
}
FLOAT32
float16tofloat32(const FLOAT16 in) {
UINT32 t1;
UINT32 t2;
UINT32 t3;
t1 = in & 0x7fff; // Non-sign bits
t2 = in & 0x8000; // Sign bit
t3 = in & 0x7c00; // Exponent
t1 <<= 13; // Align mantissa on MSB
t2 <<= 16; // Shift sign bit into position
t1 += 0x38000000; // Adjust bias
t1 = (t3 == 0 ? 0 : t1); // Denormals-as-zero
t1 |= t2; // Re-insert sign bit
return *(FLOAT32 *)&t1;
}
static inline PyObject*
getpixel(Imaging im, ImagingAccess access, int x, int y)
{
@ -702,18 +725,19 @@ _blend(ImagingObject* self, PyObject* args)
/* METHODS */
/* -------------------------------------------------------------------- */
static INT16*
_prepare_lut_table(PyObject* table, Py_ssize_t table_size)
{
int i;
FLOAT32* table_data;
float item;
INT32 data_type = TYPE_FLOAT32;
void* table_data;
INT16* prepared;
/* NOTE: This value should be the same as in ColorLUT.c */
#define PRECISION_BITS (16 - 8 - 2)
table_data = (FLOAT32*) getlist(table, &table_size,
table_data = getlist(table, &table_size,
"The table should have table_channels * "
"size1D * size2D * size3D float items.", TYPE_FLOAT32);
if ( ! table_data) {
@ -728,20 +752,31 @@ _prepare_lut_table(PyObject* table, Py_ssize_t table_size)
}
for (i = 0; i < table_size; i++) {
switch (data_type) {
case TYPE_FLOAT16:
item = float16tofloat32(((FLOAT16*) table_data)[i]);
break;
case TYPE_FLOAT32:
item = ((FLOAT32*) table_data)[i];
break;
case TYPE_DOUBLE:
item = ((double*) table_data)[i];
break;
}
/* Max value for INT16 */
if (table_data[i] >= (0x7fff - 0.5) / (255 << PRECISION_BITS)) {
if (item >= (0x7fff - 0.5) / (255 << PRECISION_BITS)) {
prepared[i] = 0x7fff;
continue;
}
/* Min value for INT16 */
if (table_data[i] <= (-0x8000 + 0.5) / (255 << PRECISION_BITS)) {
if (item <= (-0x8000 + 0.5) / (255 << PRECISION_BITS)) {
prepared[i] = -0x8000;
continue;
}
if (table_data[i] < 0) {
prepared[i] = table_data[i] * (255 << PRECISION_BITS) - 0.5;
if (item < 0) {
prepared[i] = item * (255 << PRECISION_BITS) - 0.5;
} else {
prepared[i] = table_data[i] * (255 << PRECISION_BITS) + 0.5;
prepared[i] = item * (255 << PRECISION_BITS) + 0.5;
}
}

1
src/libImaging/ImPlatform.h
View File

@ -71,6 +71,7 @@
#endif
/* assume IEEE; tweak if necessary (patches are welcome) */
#define FLOAT16 UINT16
#define FLOAT32 float
#define FLOAT64 double