- the observation in false stereoscopy of the two images which 
do not possess a stereoscopical basis but a "basis" given by the qualitative- 
quantitative difference between the two recordings; thus the contouring of 
the so called "isophenomena" may be done in an analogical, very simple and 
inexpensive way. This problem should be very attentively studied from a 
theoretical point of view and adaptations to the analogical classical 
plotting apparatus should be also done; 
- the comparison of the equidensities of the two recordings 
obtained by two way means, using photographical material specially made for 
this purpose; 
- the unsharp mask system in its analogous variant, using as mask 
one of the photographic-recordings not the unsharp classical mask; 
- the optical filtering in coherent light, in which case in the 
filtering scheme the two images obtaining the correlogram K afferent to them 
are used; the correlogram may be redisplayed under photographical aspect, 
materializing the difference between the two recordings; using possibly the 
comparison with a given signal a holographical scheme may be obtained - Fig. 
4; 
- digitally, either using the miscroscope-scanning photometer 
system with digital or analogical display or by direct processing of the 
recordings on magnetic tapes (CCT-computer compatible tapes). 
Regarding the improvement of the signal/noise ratio (S/N) with 
the efforts to assure the linearity, fidelity, repeatability of the records, 
the following are mentioned: 
- the "slicing" - dividing procedures of the images of multi 
emulsion colour-conventional or colour-composite type, may be used with 
success using the trichromie diagram and adequate sets of films. In the 
situation in which we did receive until June this year only one ERTS-1 
recording above Danube Delta of colour-composite type, the processings were 
done by its "slicing" using filters, lightings and adequate photosensible 
materials, i.e. combinations of these means. Thus we have simulated the 
recordings from the bands 4, 5 and 7 and by mixture some intermediate ones 
(one of them very close to the band 6). For the airborne recordings the 
colour-composite images have been "sliced" for the simulation of the bands 4 
and 5; 
- the enhancement and mixing procedures made in the image plan or 
by means of Fourier's double transforms, are also leading to good results in 
the processing of the recordings for their interpretation. 
CONCLUSIONS 
There is in the field of photointerpretation - remote sensing, 
and not only in it, a special interest due principally to the achievements