Remote viewing of large image files

Abstract

In general, the subject matter described in this disclosure can be embodied in methods, systems, and program products for sending image data to a client device. The computing system sends first image data from which a computing device is able to generate an initial display of an image. The initial display is a reduced-resolution version of the image that is reduced in resolution in comparison to a full resolution of the image. The computing system sends second image data from which the computing device is able to generate a subsequent display of the image. The subsequent display of the image is an intermediate-resolution version of the image that has a resolution that is higher than a resolution of the reduced-resolution version of the image and that is lower than the full resolution of the image.

1 - 18 . (canceled) 
     
     
         19 . A computer-implemented method, comprising:
 receiving, by a computing system and from a remote computing device, a request to compress information including a plurality of data values that:
 (i) represent a corresponding plurality of pixels of an image, and 
 (ii) are encoded within a corresponding plurality of multi-byte data units, such that each data value in the plurality of data values is encoded within a corresponding multi-byte data unit; 
   receiving, by the computing system, the information for which the request was received;   identifying, by the computing system, that a dynamic range of data values in the plurality of data values requires less than all bits of each corresponding multi-byte data unit in order to encode the corresponding data values;   transforming, by the computing system, the data values in the plurality of data values to increase redundancy of symbols in the information, by rearranging the bits within each of the multi-byte data units in the plurality of multi-byte data units, wherein rearranging the bits within each of the multi-byte data units includes moving a subset of bits in the multi-byte data unit from occupying part of a first byte of the multi-byte data unit and part of a second byte of the multi-byte data unit to only occupying part of the second byte of the multi-byte data unit;   replacing, by the computing system after the data values have been transformed to increase redundancy of symbols in the information, symbols in multi-byte data units in the plurality of multi-byte data units using symbols from a lookup table;   compressing, by the computing system, the information after the computing system has transformed data values to increase redundancy of symbols in the information and after the computing system has replaced symbols in multi-byte data units using symbols from a lookup table; and   transmitting the information from the computing system to the remote computing device after the information has been compressed.   
     
     
         20 . A computer-implemented method, comprising:
 receiving, by a computing system, a request to compress information including a plurality of data values that are encoded within a corresponding plurality of multi-byte data units, such that each data value in the plurality of data values is encoded within a corresponding multi-byte data unit;   receiving, by the computing system, the information for which the request was received;   identifying, by the computing system, that a dynamic range of data values in the plurality of data values requires less than all bits of each corresponding multi-byte data unit in order to encode the corresponding data values;   transforming, by the computing system, the data values in the plurality of data values to increase redundancy of symbols in the information, by rearranging the bits within each of the multi-byte data units in the plurality of multi-byte data units; and   compressing, by the computing system, the information after the computing system has transformed data values to increase redundancy of symbols in the information.   
     
     
         21 . The computer-implemented method of  claim 19 , wherein:
 the plurality of multi-byte data units are a plurality of two-byte data units;   each data value in the plurality of data values is encoded within a corresponding two-byte data unit from among the plurality of two-byte data units; and   rearranging the bits within each of the multi-byte data units includes:
 (i) identifying, by the computing system, a quantity of bits in each two-byte data unit in the plurality of two-byte data units in which data values are encoded, wherein the quantity of bits is a subset of all bits in the two-byte data unit, wherein the quantity of bits span a range of bits in each two-byte data unit, and 
 (ii) shifting, by the computing system, bits located in an upper half of the range of bits in each two-byte data unit to a different location in each two-byte data unit, while leaving bits located in a lower half of the range of bits in each two-byte data unit in their original location. 
   
     
     
         22 . The computer-implemented method of  claim 21 , wherein the range of bits occupies all of a lowest byte of the two-byte data unit and a subset of a highest byte of the two-byte data unit. 
     
     
         23 . The computer-implemented method of  claim 19 , wherein rearranging the bits within each of the multi-byte data units includes moving a subset of bits in the multi-byte data unit from occupying part of a first byte of the multi-byte data unit and part of a second byte of the multi-byte data unit to only occupying part of the second byte of the multi-byte data unit. 
     
     
         24 . The computer-implemented method of  claim 23 , wherein moving the subset of bits from occupying part of the first byte and part of the second byte to only occupying part of the second byte includes masking a portion of the first byte at which the subset of bits had previously been located. 
     
     
         25 . The computer-implemented method of  claim 19 , wherein rearranging the bits within each of the multi-byte data units includes spreading the bits that encode the data value in each multi-byte data unit of the plurality of multi-byte data units evenly between each byte of the respective multi-byte data unit, so that the corresponding data value is represented by a same or substantially-same number of bits in each byte of the multi-byte data unit. 
     
     
         26 . The computer-implemented method of  claim 25 , wherein:
 the same or substantially-same number of bits in a first byte of the multi-byte data unit is a subset of bits in the first byte; and   the same or substantially-same number of bits in a second byte of the multi-byte data unit is a subset of bits in the second byte.   
     
     
         27 . The computer-implemented method of  claim 19 , wherein:
 the request to compress the information was received at the computing system from a remote computing device; and   further comprising transmitting the information from the computing system to the remote computing device after the information has been compressed.   
     
     
         28 . The computer-implemented method of  claim 19 , wherein:
 the information includes an image;   the plurality of data values represent a corresponding plurality of pixels in the image; and   each multi-byte data unit in the plurality of multi-byte data units encodes a single data value that represents a single pixel.   
     
     
         29 . The computer-implemented method of  claim 19 , further comprising:
 replacing, by the computing system after the data values have been transformed to increase redundancy of symbols in the information, and before the information is compressed, symbols in data units in the plurality of multi-byte data units using symbols from a lookup table.   
     
     
         30 . The computer-implemented method of  claim 19 , wherein identifying that the dynamic range of the data values in the plurality of data values requires less than all bits of each corresponding multi-byte data unit includes determining that the encoding of a data value within a multi-byte data unit occupies all of the least-significant byte of that multi-byte data unit and less than all of the most-significant byte of that multi-byte data unit. 
     
     
         31 . The computer-implemented method of  claim 19 , wherein transforming the data values by rearranging the bits within each of the multi-byte data units includes shifting bits within each of the multi-byte data units so that a number of bits encoding the corresponding data value in the least-significant byte of the multi-byte data unit decreases and a number of bits encoding the corresponding data value in the most-significant byte of the multi-byte data unit increases. 
     
     
         32 . One or more computer-readable devices including instructions that, when executed by one or more computer processors, cause performance of operations that comprise:
 receiving, by a computing system, a request to compress information including a plurality of data values that are encoded within a corresponding plurality of multi-byte data units, such that each data value in the plurality of data values is encoded within a corresponding multi-byte data unit;   receiving, by the computing system, the information for which the request was received;   identifying, by the computing system, that a dynamic range of data values in the plurality of data values requires less than all bits of each corresponding multi-byte data unit in order to encode the corresponding data values;   transforming, by the computing system, the data values in the plurality of data values to increase redundancy of symbols in the information, by rearranging the bits within each of the multi-byte data units in the plurality of multi-byte data units; and   compressing, by the computing system, the information after the computing system has transformed data values to increase redundancy of symbols in the information.