visual basic print barcode label detectedges routine in Java

Creation QR-Code in Java detectedges routine

JNIEXPORT void JNICALL Java_com_msi_manning_ua2efindedges_UA2EFindEdges_detectedges( JNIEnv * env, jobject obj, jobject bitmapgray, Input grayscale jobject bitmapedges) Bitmap Output edges { Bitmap AndroidBitmapInfo infogray; void* pixelsgray; AndroidBitmapInfo infoedges; void* pixelsedge; int ret; int y; int x; int sumX,sumY,sum; Setup masks int i,j; int Gx[3][3]; int Gy[3][3]; uint8_t *graydata; Point to uint8_t *edgedata; pixel data

Gx[0][0] = -1;Gx[0][1] = 0;Gx[0][2] = 1; Gx[1][0] = -2;Gx[1][1] = 0;Gx[1][2] = 2; Gx[2][0] = -1;Gx[2][1] = 0;Gx[2][2] = 1; Gy[0][0] = 1;Gy[0][1] = 2;Gy[0][2] = 1; Gy[1][0] = 0;Gy[1][1] = 0;Gy[1][2] = 0; Gy[2][0] = -1;Gy[2][1] = -2;Gy[2][2] = -1; LOGI("detectedges in JNI code");

if ((ret = AndroidBitmap_getInfo(env, bitmapgray, &infogray)) < 0) { LOGE("AndroidBitmap_getInfo() failed ! error=%d", ret); return; } if ((ret = AndroidBitmap_getInfo(env, bitmapedges, &infoedges)) < 0) { LOGE("AndroidBitmap_getInfo() failed ! error=%d", ret); return; } LOGI("gray image :: width is %d; height is %d; stride is %d; format is %d;flags is %d",infogray.width,infogray.height,infogray.stride, infogray.format,infogray.flags); if (infogray.format != ANDROID_BITMAP_FORMAT_A_8) {

LOGE("Bitmap format is not A_8 !"); return; }

LOGI("color image :: width is %d; height is %d; stride is %d; format is %d;flags is %d",infoedges.width,infoedges.height,infoedges.stride, infoedges.format,infoedges.flags); if (infoedges.format != ANDROID_BITMAP_FORMAT_A_8) { LOGE("Bitmap format is not A_8 !"); return; } if ((ret = AndroidBitmap_lockPixels(env, bitmapgray, &pixelsgray)) < 0) { LOGE("AndroidBitmap_lockPixels() failed ! error=%d", ret); } if ((ret = AndroidBitmap_lockPixels(env, bitmapedges, &pixelsedge)) < 0) { LOGE("AndroidBitmap_lockPixels() failed ! error=%d", ret); } // modify pixels with image processing algorithm graydata = (uint8_t *) pixelsgray; edgedata = (uint8_t *) pixelsedge;

for (y=0;y<=infogray.height - 1;y++) { for (x=0;x<infogray.width -1;x++) { sumX = 0; sumY = 0; // check boundaries if (y==0 || y == infogray.height-1) { Ignore sum = 0; border pixels } else if (x == 0 || x == infogray.width -1) { sum = 0; } else { Calculate X // calc X gradient dimension for (i=-1;i<=1;i++) { for (j=-1;j<=1;j++) { sumX += (int) ( (*(graydata + x + i + (y + j) * infogray.stride)) * Gx[i+1][j+1]); } } Calculate Y // calc Y gradient dimension for (i=-1;i<=1;i++) { for (j=-1;j<=1;j++) { sumY += (int) ( (*(graydata + x + i + (y + j) * infogray.stride)) * Gy[i+1][j+1]); } } sum = abs(sumX) + abs(sumY); } if (sum>255) sum = 255; Constrain if (sum<0) sum = 0; pixel values

*(edgedata + x + y*infogray.width) = 255 - (uint8_t) sum; }

} AndroidBitmap_unlockPixels(env, bitmapgray); AndroidBitmap_unlockPixels(env, bitmapedges); }

Like the prior function, this one takes two Bitmap arguments, both of which are grayscale images. The first contains the grayscale image B created in the converttogray method. The second bitmap argument C becomes the edges only version of the image. A number of variables D are defined to aid in the edge-detection process. Like the prior function, we have local pointers E to the image data. The Sobel Edge Detection algorithm involves a mathematical operation known as a convolution, which requires initializing a pair of convolution masks F. The convolution must be performed across the entire image G with the exception of the border pixels, which are skipped H. First the calculations are made in the x dimension I and then in the y dimension J. Once the calculations have been performed for a particular pixel, a new value is calculated based on the surrounding pixels and stored in the output image 1). Prior to storing a value, the new pixel value is constrained to be between 0 and 255 1!. You re now ready to compile this code, but before you can do that you need to define the make file for the library.

In addition to the C source file, you require a make file to instruct the NDK on how the library is compiled. The following listing contains the make file used with this library.