Region-selective fluoroscopic image compression
View Patent ↗A method for displaying a sequence of fluoroscopic images of a subject defines, within the image area of a digital image receiver and in response to one or more viewer instructions, a region of interest and a background region that lies outside the defined region of interest. A succession of fluoroscopic images is obtained from the digital image receiver and, for image pixels within each of the succession of fluoroscopic images, background region pixel data are encoded and transmitted to the display apparatus using a lossy encoding. Region of interest pixel data is transmitted to the display apparatus using a lossless encoding. The succession of fluoroscopic images is displayed.
1. A method for displaying a sequence of fluoroscopic images of a patient, comprising:
defining, within the image area of a digital image receiver, in response to one or more viewer instructions, a region of interest and a background region disposed outside the defined region of interest;
obtaining a succession of fluoroscopic images at a digital image receiver and, for image pixels within each of the succession of images:
(i) encoding and transmitting background region pixels to a display apparatus using a lossy encoding, with transmission at a first refresh rate, wherein more than one type of lossy encoding is used for the background region pixels, according to distance from the region of interest; and
(ii) transmitting region of interest pixels to the display apparatus using a second encoding, with transmission at a second refresh rate that is higher than the first refresh rate; and
displaying the succession of fluoroscopic images on the display apparatus.
2. The method of claim 1 wherein the pixel data is transmitted wirelessly.
3. The method of claim 1 wherein the one or more viewer instructions are entered using a mouse or other pointer.
4. The method of claim 1 wherein the one or more viewer instructions are entered using a touch screen.
5. The method of claim 1 wherein the one or more viewer instructions define a rectangular region of interest.
6. The method of claim 1 wherein the one or more viewer instructions define a non-rectangular region of interest.
7. The method of claim 1 wherein the one or more viewer instructions comprise operator actions for setting up or initiating an exposure.
8. The method of claim 1 wherein the more than one type of lossy encoding includes transform-based encoding.
9. The method of claim 1 wherein the more than one type of lossy encoding includes bit field encoding.
10. The method of claim 1 wherein the more than one type of lossy encoding includes predictive encoding.
11. The method of claim 1 wherein displaying the succession of fluoroscopic images comprises displaying the region of interest and background region with different image contrast, brightness level, tone scale, filtering, or color.
12. The method of claim 1 wherein the one or more viewer instructions indicate use of an object to define the region of interest.
13. The method of claim 1 further comprising shifting the position of the region of interest according to operator gaze.
14. The method of claim 1 further comprising shifting the position of the region of interest according to movement of an object.
15. The method of claim 1 wherein a portion of the pixel data for either or both the background region and the region of interest is transmitted as difference data between successive image frames.
16. The method of claim 1 wherein the second encoding is lossless.
17. The method of claim 1 wherein the second encoding is less lossy than the lossy encoding used for background pixels.