Image-audio transformation system

• US 5,097,326 A
• Filed: 07/27/1990
• Issued: 03/17/1992
• Est. Priority Date: 07/27/1989
• Status: Expired due to Fees

• Current Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Original Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Inventors: Meijer, Peter B. L.
• Primary Examiner(s): Groody, James J.
• Assistant Examiner(s): LEE, MICHAEL
• Application Number:
  US07/558,680
• Time in Patent Office: 599 Days
• Field of Search: 358/94, 358/93, 358/105, 358/107, 381/124, 381/61
• US Class Current: 348/62
• CPC Class Codes: A61F 9/08 Devices or methods enabling eye-patients to replace direct visual perception by another kind of perception
• CPC Class Codes: G09B 21/006 using audible presentation of the information

Abstract

In a device for converting visual images into representative sound information especially for visually handicapped persons an image processing unit is provided with a pipelined architecture with a high level of parallelisum. An image is scanned in sequential vertical scanlines and the acoustical representatives of the scanlines are produced in real time. Each scanline acoustical representation is formed by sinusoidal contributions from each pixel in the scanline, the frequency of the contribution being determined by the position of the pixel in the scanline and the amplitude of the contribution being determined by the brightness of the pixel.

Claims

1. Transformation system for converting a visual image signal representative of pixels in sequential scanlines through an image into an acoustic signal composed of sequential acoustic signal sections respectively corresponding to said scanlines, each acoustic signal section being formed of sequential output amplitude samples equally spaced apart by a predetermined time step and representing a superposition of signal contributions from respective pixels in the corresponding scanline, each signal contribution from a pixel being determined from a sinusoid frequency due to a position, of said pixel in the scanline and a sinusoid amplitude due to a brightness of said pixel, said system comprising:

a processing unit having an image signal input for a current image and an output, said unit comprising;

first memory means fed by said image signal input for storing sinusoid amplitudes respectively due to brightnesses of the pixels in a current scanline to be processed in the current image;

second memory means for storing phase increments due to the pixel positions in the current scanline respectively corresponding to sinusoid frequencies due to the pixel positions in said current scanline times the predetermined time step;

third memory means for storing cumulated phases for the signal contributions from the respective pixels positions in said current scanline to a currently processed output amplitude sample;

first summing means responsive to data outputs of said first and second memory means for forming a current cumulated phase for the signal contribution from a currently processed pixel position in said current scanline as a sum of a last cumulated phase for the signal contribution from said currently processed pixel position, stored in said second memory means, and the phase increment due to said currently processed pixel position, stored in said first memory means, and for updating said third memory means with said sum;

sine means responsive to a data output of the first memory means and to the current cumulated phase formed by the summing means for forming a signal contribution to the currently processed output amplitude sample due to the currently processed pixel position as a product of the sinusoid amplitude and a sinusoidal function of said current cumulated phase for the currently processed pixel position; and

second summing means responsive to the output of the sine means for forming a cumulative sum of contributions to the currently processed amplitude sample due to all pixel positions in the current scanline, having an output comprising the output of said image processing unit;

image input means coupled to said image signal input for successively updating the current image at a frame rate; and

audio transducer means responsive to the output of said image processing unit for successively forming the acoustic signal sections corresponding to each successive current scanline.

2. The system as claimed in claim 1, wherein said sine means comprises a ROM containing scaled sine values at memory addresses given by the combination of the current cumulated phase and sinusoid amplitude for the currently processed pixel position.

3. Transformation system as claimed in claim 1, characterized in that said image input means comprises a portable image sensing system for feeding said image signal input of said image processing unit.

4. Transformation system as claimed in claim 1, wherein said image input means updates said current image at a television frame rate and said image processing unit operates in real-time on successively updated current images.

5. Transformation system as claimed in claim 4, characterized in that said image processing unit comprises a pipelined digital processing architecture.

6. Transformation system as claimed in claim 1, wherein each scanline is a pixel column.

7. Transformation method for converting a visual image signal representative of pixels of sequential scanlines through an image into an acoustic signal composed of sequential acoustic signal sections respectively corresponding to said scanlines, each acoustic signal section being formed of sequential output amplitude samples equally spaced apart by a predetermined time step and representing a superposition of signal contributions from respective pixels in the corresponding scanline, each signal contribution from a pixel being determined from a sinusoid frequency due to a position of said pixel in the scanline and a sinusoid amplitude due to a brightness of said pixel, said method comprising:

first storing sinusoid amplitudes due to brightnesses of pixels in a current scanline to be processed;

second storing phase increments due to the pixel positions in the current scanline respectively corresponding to the sinusoid frequencies due to the pixel positions in the scanline times the predetermined time step;

third storing cumulated phases for the signal contributions from the respective pixel positions in said current scanline to a currently processed output amplitude sample;

first forming a current cumulated phase for the signal contribution from a currently processed pixel position in said current scanline as a sum of the third stored cumulated phase for said currently processed pixel position and the second stored phase increment for due to the currently processed pixel position, and updating the third stored cumulative phase for the currently processed pixel position with said sum;

second forming the signal contribution to the currently processed output amplitude sample due to the currently processed pixel position as a product of the sinusoid amplitude and a sinusoidal function of said current cumulated phase for the currently processed pixel position; and

third forming a cumulative sum of the second formed contributions to the currently processed amplitude sample due to all pixel positions in said scanline.

8. The method as claimed in claim 7, wherein said second forming comprises addressing a ROM containing scaled sine values at an address formed by the combination of the current cumulated phase and sinusoid amplitude for the currently processed pixel position.

9. A method as claimed in claim 7, wherein the sinusoid frequency associated with each pixel position increases geometrically with change of pixel position in a predetermined direction along a scan line.