Humberto Ochoa

Publications (37) View all

• Source

  Available from: Humberto Ochoa

  Chapter: Biometric Human Identification of Hand Geometry Features Using Discrete Wavelet Transform

  Osslan Osiris Vergara Villegas, Humberto de Jesu?s Ochoa Domi?nguez, Vianey Guadalupe Cruz Sa?nchez, Leticia Ortega Maynez, Hiram Madero Orozco
  09/2011; , ISBN: 978-953-307-654-6
• Conference Proceeding: A modified hybrid DCT-SVD image-coding system

  Y. Wongsawat, H. Ochoa, K.R. Rao
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  ABSTRACT: This paper proposes a hybrid image-coding system that combines the DCT and the SVD. A criterion based on the standard deviation of 8×8 blocks of an image is used to choose between DCT and SVD. The DCT is used to transform the high correlated blocks of the image, while the SVD is used to transform the low correlated blocks. The AMVQ is used to encode the eigenvectors of the blocks encoded using the SVD and the uniform quantization is used to encode the DCT coefficients. The simulation results show good image quality at low bit rates.
  TENCON 2004. 2004 IEEE Region 10 Conference; 12/2004
• Source

  Available from: Humberto Ochoa

  Conference Proceeding: A modified hybrid DCT-SVD image-coding system for color image

  Y. Wongsawat, H. Ochoa, K.R. Rao, S. Oraintara
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  ABSTRACT: We propose a modified hybrid DCT-SVD image-coding system (MHDCTSVD) to encode both monochromatic and color images. The color (RGB) components are transformed into YCbCr. Cb and Cr components are downsampled by a factor of two along both the horizontal and vertical directions. The standard deviation of 8×8 blocks of the Y component is used to select between DCT and SVD. The DCT is used to transform the highly correlated blocks of the YCbCr components, while the SVD is used to transform blocks with low correlation. The simulation results show good image quality at low bit rates compared with the conventional hybrid DCT-SVD image-coding algorithm.
  Communications and Information Technology, 2004. ISCIT 2004. IEEE International Symposium on; 11/2004
• Conference Proceeding: A hybrid DWT-SVD image-coding system (HDWTSVD)

  H. Ochoa, K.R. Rao
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  ABSTRACT: In this paper, the authors proposed the HDWTSVD system to encode both monochromatic and color images. Before encoding the color images, the color components (RGB) are transformed into YCbCr. Cb and Cr components are downsampled by a factor of two, both horizontally and vertically, before sending them through the encoder. If the input is a monochromatic image, only one frame (luminance) is encoded. A criterion based on the average standard deviation of 8times8 subblocks of the Y component is used to choose DWT or SVD for all the components. Standard test images are compressed based on the proposed system
  Circuits and Systems, 2003 IEEE 46th Midwest Symposium on; 01/2004
• Conference Proceeding: A modified hybrid DWT-SVD image-coding system (HDWTSVD) for monochromatic images

  H. Ochoa, K.R. Rao
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  ABSTRACT: In this paper, we propose a modification of the HDWTSVD system to encode monochromatic images. The modification was carried out in the SVD encoder, where the eigenvalues and eigenvectors are scalar and vector quantized respectively. If the MSE of the first three eigenvectors, with respect to the codevectors in the codebooks, is greater than a threshold then, the eigenvectors are scalar quantized and sent, otherwise the indices of the codevectors are sent. The remaining eigenvectors are quantized using small codebooks. Results show that the algorithm performs well for bitrates above and below 1 bpp.
  Video/Image Processing and Multimedia Communications, 2003. 4th EURASIP Conference focused on; 08/2003