Fix precision issue in GPUImageLookupFilter

Author: jonan

library/src/jp/co/cyberagent/android/gpuimage/GPUImageLookupFilter.java

@@ -26,19 +26,19 @@ public class GPUImageLookupFilter extends GPUImageTwoInputFilter {
             " uniform sampler2D inputImageTexture;\n" +
             " uniform sampler2D inputImageTexture2; // lookup texture\n" +
             " \n" +
-            " uniform float intensity;\n" +
+            " uniform lowp float intensity;\n" +
             " \n" +
             " void main()\n" +
             " {\n" +
-            "     lowp vec4 textureColor = texture2D(inputImageTexture, textureCoordinate);\n" +
+            "     highp vec4 textureColor = texture2D(inputImageTexture, textureCoordinate);\n" +
             "     \n" +
-            "     mediump float blueColor = textureColor.b * 63.0;\n" +
+            "     highp float blueColor = textureColor.b * 63.0;\n" +
             "     \n" +
-            "     mediump vec2 quad1;\n" +
+            "     highp vec2 quad1;\n" +
             "     quad1.y = floor(floor(blueColor) / 8.0);\n" +
             "     quad1.x = floor(blueColor) - (quad1.y * 8.0);\n" +
             "     \n" +
-            "     mediump vec2 quad2;\n" +
+            "     highp vec2 quad2;\n" +
             "     quad2.y = floor(ceil(blueColor) / 8.0);\n" +
             "     quad2.x = ceil(blueColor) - (quad2.y * 8.0);\n" +
             "     \n" +