A small question about the function -- insertObjectAnnotation.

The funtion insertObjectAnnotation can be used to insert some annotation and output a RGB image. The usage of this function is not hard. However, the output image is almost white.

The original image and annotated image are shown in http://t1.qpic.cn/mblogpic/4f0c4b6023e0068989ba/460.jpg. The original image, I,is full-disk solar image with the size 256-by- 256 and the intensity vary from 0 to 4726.

Some code:

     rgb = insertObjectAnnotation(I, 'rectangle', bbox, 'FI');

     figure,subplot(1,2,1),imshow(I,[]),title('original image')
            subplot(1,2,2),imshow(rgb,[]),title('Insert Annotation')

bbox is a 30-by-4 matrix.

Why the result is so strange.

[Jan]

Please define "strange" exactly. How do you obtain "the output image"? What is an intensity of -4? What is "I"? Is it an indexed image and the troubles come from an implicit conversion to a double RGB image? The shape of the sun differs between the both pictures. Is this expected?

[Donghui Sun]

Sorry for my vague expression.

Answer 1

[Dima Lisin]

What is the data type of your input image? Try converting the image to a double and rescaling it to the range [0,1] before calling insertObjectAnnotation. im2double should do that for you.