Opencl-sobel detection and opencl-sobel

Opencl-sobel detection and opencl-sobel

Comparison of the time of the C version, neon, and GPU detected by sobel.

Platform: LG G3, Adreno 330, img size 3264x2448

Sobel:

C code	Neon	GPU
73	13	42 + 3.7 + 6.6

Unit: ms GPU time = memorytime + Queued time + Run time

	Sobel org	Sobel vector	Sobel vector + mem_fence
Queued time	4.6	7.2	2.8
Wait time	0.07	0.09	0.07
Run time	66.9	7.3	6.6

Typedef unsigned char BYTE; void sobel (BYTE * src, int w, int h, BYTE * Ix, BYTE * Iy) {int src_step = w; int dst_step = w; int x, height = h-2; BYTE * dstX = Ix + dst_step; BYTE * dstY = Iy + dst_step; for (; height --; src + = src_step, dstX + = dst_step, dstY + = dst_step) {const BYTE * src2 = src + src_step; const BYTE * src3 = src + src_step * 2; for (x = 1; x <W-1; x ++) {short t0 = 0; short t1 = 0; t0 =-src [x-1] + src [x + 1]; t1 = src [x-1] + (src [x] <1) + src [x + 1]; t0 + = (-src2 [x-1] + src2 [x + 1]) <1); t0 + =-src3 [x-1] + src3 [x + 1]; t1-= (src3[ x-1] + (src3 [x] <1) + src3 [x + 1]); dstX [x] = t0> 3; dstY [x] = t1> 3 ;}} void sobel_neon (BYTE * src, int w, int h, BYTE * Ix, BYTE * Iy) {int src_step = w; int dst_step = w; int x, height = h-2; BYTE * dstX = Ix + dst_step; BYTE * dstY = Iy + dst_step; for (; height --; src + = src_step, dstX + = dst_step, dstY + = dst_step) {const BYTE * src2 = src + src_step; const BYTE * src3 = src + src_step * 2; x = 1; while (x + 8) <= W-1) {uint8x8_t left = vld1_u8 (src + x-1); uint8x8_t mid = vld1_u8 (src + x ); scheme right = vld1_u8 (src + x + 1); int16x8_t t0 = Scheme (vsubl_u8 (right, left); int16x8_t t1 = vaddq_s16 (scheme (vaddl_u8 (left, right )), values (vshll_n_u8 (mid, 1); left = vld1_u8 (src2 + x-1); right = vld1_u8 (src2 + x + 1); int16x8_t temp = values (vsubl_u8 (right, left); t0 = vaddq_s16 (t0, vshlq_n_s16 (temp, 1); left = vld1_u8 (src3 + x-1); mid = vld1_u8 (src3 + x ); right = vld1_u8 (src3 + x + 1); t0 = vaddq_s16 (t0, clerk (vsubl_u8 (right, left); temp = vaddq_s16 (Clerk (vaddl_u8 (left, right), round (vshll_n_u8 (mid, 1); t1 = vsubq_s16 (t1, temp); vst1_s8 (int8_t *) dstX + x, vshrn_n_s16 (t0, (3); vst1_s8 (int8_t *) dstY + x, vshrn_n_s16 (t1, 3); x + = 8;} while (x) <W-1) {short t0 = 0; short t1 = 0; t0 =-src [x-1] + src [x + 1]; t1 = src [x-1] + (src [x] <1) + src [x + 1]; t0 + = (-src2 [x-1] + src2 [x + 1]) <1); t0 + =-src3 [x-1] + src3 [x + 1]; t1-= (src3[ x-1] + (src3 [x] <1) + src3 [x + 1]); dstX [x] = t0> 3; dstY [x] = t1> 3; x ++ ;}}}View Code