我正在寻找一种快速而有效的边缘检测着色器或边缘网格,用于视频应用。由于这将在移动设备上完成,因此我需要优先考虑性能而不是准确性。无论如何,我都会模糊输出,并且我看到的所有边缘检测算法都倾向于通过比较原始图像和模糊图像来完成。我认为模糊往往会导致最大的性能问题。
我有一个像这样的函数正在工作:
vec4 edge()
{
float K00 = -1.0;
float K01 = -2.0;
float K02 = -1.0;
float K10 = 0.0;
float K11 = 0.0;
float K12 = 0.0;
float K20 = 1.0;
float K21 = 2.0;
float K22 = 1.0;
vec2 ox = vec2 (0.0,0.0);
ox[0] = width;
vec2 oy = vec2 (0.0,0.0);
oy[1] = height;
float g00, g01, g02;
float g10, g11, g12;
float g20, g21, g22;
vec4 CC;
vec2 PP = TextureCoord - oy;
CC = texture2D(blurredFrame, vec2(PP-ox));
g00 = getGrey(CC);
CC = texture2D(blurredFrame, vec2(PP));
g01 = getGrey(CC);
CC = texture2D(blurredFrame, vec2(PP+ox));
g02 = getGrey(CC);
PP = TextureCoord;
CC = texture2D(blurredFrame, vec2(PP-ox));
g10 = getGrey(CC);
CC = texture2D(blurredFrame, vec2(PP));
g11 = getGrey(CC);
CC = texture2D(blurredFrame, vec2(PP+ox));
g12 = getGrey(CC);
PP = TextureCoord + oy;
CC = texture2D(blurredFrame, vec2(PP-ox));
g20 = getGrey(CC);
CC = texture2D(blurredFrame, vec2(PP));
g21 = getGrey(CC);
CC = texture2D(blurredFrame, vec2(PP+ox));
g22 = getGrey(CC);
float sx = 0.0, sy = 0.0;
sx = sx + g00 * K00;
sx = sx + g01 * K01;
sx = sx + g02 * K02;
sx = sx + g10 * K10;
sx = sx + g11 * K11;
sx = sx + g12 * K12;
sx = sx + g20 * K20;
sx = sx + g21 * K21;
sx = sx + g22 * K22;
sy = sy + g00 * K00;
sy = sy + g01 * K10;
sy = sy + g02 * K20;
sy = sy + g10 * K01;
sy = sy + g11 * K11;
sy = sy + g12 * K21;
sy = sy + g20 * K02;
sy = sy + g21 * K12;
sy = sy + g22 * K22;
float dist = sqrt(sx * sx + sy * sy);
return dist > threshold ? vec4 (0,0,0,1) : vec4 (1,1,1,1);
}
我看到的所有示例都是这样的,似乎都集中在桌面平台上——要在iPhone或Android设备上获得良好的帧速率太过复杂和昂贵。这将仅用于2D应用程序,速度至关重要。
有什么想法可以使其更加高效,或者可能有更好的替代方案吗?谢谢大家。